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Family Euphorbiaceae
Para rubber
Hevea brasiliensis (Willd. ex A.Juss.) Müll.Arg.
Xiang jiao shu

Scientific names Common names
Hevea brasiliensis (Willd. ex A.Juss.) Müll.Arg.            Para rubber (Philippines)
Hevea brasiliensis f. acreana (Ule) Ducke            Natural rubber (Engl.)
Hevea brasiliensis var. acreana Ule            Rubber plant (Engl.)
Hevea brasiliensis var. angustifolia Ule ex Huber Rubber tree (Engl.)
Hevea brasiliensis f. angustifolia (Ule ex Huber) Ule Sharinga tree (Engl)
Hevea brasiliensis monstr. granthamii Barth             
Hevea brasiliensis var. janeirensis (Müll.Arg.) Pax  
Hevea brasiliensis var. latifolia Ule ex Huber           
Hevea brasiliensis f. latifolia (Ule ex Huber) Ule         
Hevea brasiliensis f. randiana (Huber) Ducke         
Hevea brasiliensis var. randiana (Huber) Pax         
Hevea brasiliensis var. stylosa Huber         
Hevea granthamii Bartlett             
Hevea janeirensis Müll.Arg.   
Hevea randiana Huber         
Hevea sieberi Warb.         
Siphonia janeirensis (Müll.Arg.) O.F.Cook  
Siphonia ridleyana O.F.Cook  
Hevea brasiliensis (Willd. ex A.Juss.) Müll.Arg. is an accepted species. KEW: Plants of the World Online

Other vernacular names
CHINESE: Xiang jiao shu.
DUTCH: Braziliaanse rubberboom.
FRENCH: Hevea, Arbre de Para, Arbre a caoutchouc.
INDONESIAN: Pohon karet para.
MALAY: Pokok getah.
PORTUGUESE: Seringueria, Seringueria-branca, Pau-seringa, Seringueira-rosada, Seringueira-verdadeira.
SPANISH: Siringa, Jebe.
SUNDANESE: Tuwuhan karet.
VIETNAMESE: Cay cao su.

Gen info
- Hevea is a genus of flowering plants in the spurge family Euphorbiaceae, with about 10 members. The most economically important species is the rubber tree, H. brasiliensis.
- The genus was first described in 1775b by French botanist and explorer Jean Baptiste Christophore Fusée Aublet. (2)
- Hevea brasiliensis, the rubber tree, is a robust perennial crop with natural rubber as its main product. The majority of rubber production in the Philippines is sourced from Mindanao. In 2014, the country was ranked 10th in the world in terms of natural product production; in 2021, the top producing province was Cotobato, followed by Zamboanga and Basilan. (4)
- Natural rubber is largely produced in Asia, accounting for almost 94% of global requirement (Thailand, Indonesia, Malaysia, and the Philiippines). The Philippines is ranked 6th as a world rubber producing country. ( (4)
- The industry is challenged by natural calamities and long dry spells, causing only 186,000 trees out of 570,000 producing latex. (4) The tree requires a tropical or subtropical climate with a minimum of about 1,200 mm (50 in) per year of rainfall, and no frost. If frost does occur, the results can be disastrous for production. One frost can cause the rubber from an entire plantation to become brittle and break once it has been refined. (2)
- In plantations the trees are generally smaller because they grow more slowly when tapped for latex trees. The latex production declines when the trees age, and are cut down when no longer economically productive. (2)
- Of the 10 species of the genus Hevea, only H. brasiliensis is planted commercially for its rubber.  Worldwide, approximately 14 million hectares of land is planted with rubber. In 2020, about 13 million tons of rubber was produced globally. Production of natural rubber is mainly contributed by Asia (88%), Africa (10%), and Latin America (2%). In Asia, Thailand, Indonesia, Vietnam, and Malaysia represent 70% of global supply (IRSG,2021). (41)

• Large trees, up to 30 m tall, with much milky juice. Petiole 5-15 cm, apex usually with 2(-4) glands; leaflets 3, elliptic, 10-25 × 4-10 cm, both surfaces glabrous, base cuneate, margin entire, apex acute to acuminate; lateral veins 10-16, reticulate veins prominent. Panicles axillary, to 16 cm, gray-white pubescent. Male flowers: sepals ovate-lanceolate, ca. 2 mm; stamens 10, in 2 series; anthers 2-locular, longitudinally dehiscent. Female flowers: sepals as in male, but larger; ovary (2 or)3(-6)-locular; stigmas 3, sessile. Capsules ellipsoidal, 5-6 cm in diam., with 3 longitudinal grooves, apex rostrate, base retuse; epicarp thinner, with reticulate stripes; endocarp thicker, woody. Seeds ellipsoidal, gray-brownish, maculate-striate. (Flora of China)

Hevea brasiliensis is a tall deciduous tree growing to a height of up to 43 m (141 ft) in the wild. Cultivated trees are usually much smaller because drawing off the latex restricts their growth. Trunk is cylindrical and may have a swollen, bottle-shaped base. Bark is some shade of brown, and the inner bark oozes latex when damaged. Leaves have three leaflets, spirally arranged. Inflorescences include include separate male and female flowers. Glowers are pungent, creamy-yellow and have no petals. Fruit is a capsule that contains three large seeds; it opens explosively when ripe. 

- Introduced, cultivated.
- Native of South America introduced to Southeast Asia during the 19th century.

- Native to Bolivia, Brazil North, Brazil South, Brazil West-Central, Colombia, French Guiana, Peru, Venezuela. (1)

- Study of ethyl acetate (EA), ethanol (E), chloroform (C) and aqueous (A) extracts of leaves yielded flavonoid, alkaloids, protein, reducing sugar, and steroids in all test extracts. Other phytochemicals were saponins (C,A), tannins, amino acids, and cardiac glycosides (EA, E, C)
, with absence of triterpenoids and anthraquinones. (see study below) (7)
- Phytochemical study of methanol extract of roots yielded alkaloids, carbohydrates, glycosides, saponins, phytosterols, proteins and amino acids, fats and fixed oils. (8)
- Ethanol extract of dried leaves yielded presence of alkaloids, anthraquinones, cardiac glycosides, coumarin, flavonoids, saponin, steroids, tannins, and terpenoids. Total phenolic content was 63.95 mg GAE/g. (see study below) (10)
- Three main latex fractions separated by high speed centrifugation are rubber cream, centrifuged serum (C-serum) and a bottom fraction that mainly consists of a vacuole-like organelle known as lutoid body. The fluid released from ruptured lutoid bodies is known as B-serum. (see study below) (12)
- The latex is a colloidal dispersion where various micrometric objects, mainly rubber particles and lutooids are dispersed in cytoplasmic serum (C-serum). Rubber is most abundant, followed by C-serum, and lutoids. Composition of fresh latex is about 60% water, 35% of cis-1,4-polyisoprene and 5% non-isoprene molecules. Non-isoprenes are biochemical compounds, mostly proteins, lipids, carbohydrates, and minerals, in non-homogenous distribution in the fractions of latex. (see study below) (28)
- Extraction yield of rubber seed oil was 19.32 ± 0.54%. Fatty acid components were palmitic (18.90 ± 0.55%), stearic (10.91 ± 0.25%), oleic (35.91 ± 1.97%), and linoleic (33.31 ± 1.56%) acids. (see study below) (29)
- Study of decorticated H. brasiliensis seeds yielded 85.7% dry matter, 26.1% crude protein, 43.0% crude fiber, 13.8% nitrogen free extract, 11.0% ether extract, and 1.8% ash. (see study below) (34)
- Study of Hevea brasiliensis skim for chemical constituents isolated 13 compounds and twelve were identified as: Friedelin (1), lupeol (2), ß-sitosterol (3), hexadecanoic acid (4), heptadecanoic acid (5), daucosterol (6), nicotine acid (7), succinic acid (8), gallic acid (9), fructose (10), quebrachitol (11),
6-hydroxy-cleistopholine (12). (39)
- Nutritional composition study of rubber seed yielded a protein content of 18%, and the most limiting amino acid was threonine, with a chemical score of 71.6. Iron, calcium, and phosphorus contents were 6.2, 109, and 429 mg/100 g, respectively.  Fat content was 48% with total energy value of 702 cal/100 g (2,948 Kj/100g. Total cyanide content in fresh seed was 130-230 mg/100g, 6% in free form and 94% as bound cyanide. (see study below) (40)

- Studies have suggested antibacterial, wound healing, anti-fungal, anticancer, antiproliferative, antimelanogenesis, antioxidant, anti-inflammatory, nutritive, hemagglutinating properties.

Parts used
Latex, leaves, seed, seed oil.


- While the seeds are considered poisonous, they are staple food for local peoples in the jungle. The seeds require prolonged soaking or boiling to destroy cyanic poisons. (33)
- Seeds are used as famine food.
- No reported folkloric medicinal use in the Philippines.
- Agrofrestry: As a reforestation crop, it can help control the level of carbon dioxide in the atmosphere. Also one of the most profitable agroindustrial ventures in the country, grown in Mindanao with
commercial success. (4)
- Industries: Used in varied applications: industrial, technological, fashion, and household uses. A recent breakthrough was its use as a rubber component product in human pancreas. (5)
- Forage: Study showed potential for leaves as herbal nutrition for goats. (see study below) (26)
- Wood: Used for making furniture, interior finish, moulding, etc.
- Seed oil: Yields a semi-drying pale yellow oil used for soap-making, paint, varnish, and treatment against house flies and lice. (33)

Biomedical Applications / Latex:
Nature has provided us with the natural rubber latex from the rubber tree Hevea brasiliensis, a natural polymer that is biocompatible and has proven t7o induced tissue repair by enhancing vasculogenesis, guiding and recruiting cells for osteogenesis, and acting as a solid matrix for controlled drug release. Latex membranes can be applied to dermal wounds to promote healing. NRL serum has angiogenic, anti-inflammatory, antimicrobial, and osteogenic properties. (6)
Antibacterial / Leaves: Butyl alcohol, acetone, and chloroformic extracts of H. brasiliensis leaves yielded secondary metabolites such as flavanoids, alkaloids, tannins, cardiac glycosides, steroids, etc. Extracts showed antimicrobial activities against E. coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa, with activity stronger than standard antibiotics. (see constituents above) (7)
Increased Vascular Permeability / Angiogenesis / Wound Healing / Latex: Increases in vascular permeability and angiogenesis are crucial to wound repair. Increased vascular permeability allows cytokines and growth factors to reach damaged tissue. Study evaluated the healing properties and angiogenic activity of natural latex from H. brasiliensis, using chick embryo chorioallantoic membrane assay and rabbit ear dermal ulcer method. Serum fraction showed angiogenic effect and enhanced vascular permeability. It significantly accelerated wound healing in dermal ulcers. (8)
Analgesic / Antidiarrheal / Roots: Study evaluated the analgesic and antidiarrheal activity of methanol extracts of Hevea brailiensis roots. For analgesic activity using acetic acid induced writhing, the extract at doses of 250 and 500 mg showed significant activity compared to diclofenac Na. For antidiarrheal activity, the extract significantly reduced charcoal propulsion. (see constituents above) (9)
Antioxidant / Antimicrobial / Leaves: Ethanolic extract of dried leaves exhibited notable effectiveness in scavenging free radicals (71.2%) at 500 µg/ml concentration and antioxidant capacity (lowest IC50 of 42.57 µg/ml). The leaf extract showed inhibition zones on all selected bacteria viz., gram-positive Bacillus subtilis, Staphylococcus aureus, S. epidermis and gram-negative Escherichia coli, Pseudomonas aeruginosa at 200 mg/ml concentration. (see constituents above) (10)
Antifungal / Anti-Aspergillus niger / Latex C-Serum: The latex C-serum from H. brasiliensis exhibited specific antifungal activity against Aspergillus niger, but not Candida albicans. Low toxicity of the C-serum was demonstrated in Brine Shrimp Lethality Assay (BSLA) with LC50 of 98.4 mg/ml. The extract has potential as relatively low cost resource because of simplicity of latex preparation and abundance of latex that can be obtained in rubber producing regions. (11)
Anti-Proliferative Effect on Human Breast Cancer Epithelial Cells / Latex B-Serum: Study evaluated the specific anti-proliferation property of H. brasiliensis latex B-serum sub-fractions against human breast cancer epithelial cell line MCF-7 and MDA-MB231. Results showed the latex whole B-serum and DBP sub-fraction exerted a specific anti-proliferation activity against MDA-MB231, with little effect on non-cancer-origin cells. With low toxicity in BLST (Brine ShrimP Lethality Test) results suggest potential use of B-serum sub-fractions in cancer treatment. (see constituents above) (12)
Anti-Candida albicans Activity / Latex B-Serum: Study evaluated the antifungal activity of Hevea latex B-serum against Candida albicans (round cell fungus) and Aspergillus niger (filamentous fungus). Results showed antifungal activity of latex B-serum specific to C. albicans but not to A. niger. MIC for C. albicans was 2.5 mg/ml. BSLT showed non-toxicity of the serum with LC50 of 461.0 mg/ml. (13)
Cytotoxicity / Free Radical Scavenging / Latex C-Serum: Study evaluated the invitro antioxidant activity of latex C-serum of H. brasiliensis and cytotoxicity of the fraction in two human cell lines derived from normal tissue (MRC-5 and CCD 1059sk). Latex C-serum showed potent antioxidant activity, effectively scavenging hydroxyl and nitric oxide radicals and hydrogen peroxide comparable to standard antioxidant, ascorbic acid. The cytotoxicity of latex C-serum appears to be cell line dependent and concentrations up to 50 µg/mL and up to 200 µg/mL can be used without interference in cell viability of MRC-5 cells e CCD 1059 sk cells, respectively. (14)
Porosity Effects for Release of Biomedical Applications: Natural rubber latex biomedical (NRLb) obtained from rubber tree has shown great potential in biomedicine and biomaterial applications. NRLb has been used as a physical barrier against infectious agents and in controlled release of drugs and extracts. Study evaluated polymerized NRLb and the resultant membrane porosity and its effects on surface morphology, water vapor permeability, mechanical properties, hemolytic activity, and cytotoxicity. Drug release rates increased with porosity and membranes controlled protein release up to 12h. Water vapor permeability increase with quantity of pores. Results suggest the porosity control of natural latex membranes can be used to modulate properties and made them suitable for biomedical applications,  such as wound dressings, modulated gas-exchange membranes and controlled drug delivery systems. (15)
Latex as Source of Allergen Exposure: The prevalence of allergic reactions to H. brasiliensis natural rubber latex among high-risk health care  workers and patients undergoing multiple surgeries has diminished from epidemic levels in the mid-1990s. The decrease has been attributed to avoidance of powdered latex gloves and improved quality control in manufacturing process. However, sensitization continues from exposure to less-established sources. Study provides overview for testing methods for sensitization include quantifying of total protein, measurement of antigenic protein, Hevea allergenic proteins (H. brasiliensis 1, 3, 5, and 6.02) content in natural rubber latex toy balloons, dental dams, medical gloves, nitrile and guayule medical gloves. (16)
Comparative Study / Accelerated Regeneration of Bone Tissue by Latex Membranes: Bone loss is a common problem after accidental traumas, cancers, congenital defects, and surgical procedures. Large bone restoration usually involves complex invasive procedures such as grafting. Study assesses the osteogenic potential of natural rubber (NR) membranes of clones of high bioactivity of H. brasiliensis (RRIM 600 and IAN 873) and Hancornia speciosa. A fibrin sealant (FS) was used to fix the membranes as a replacement for cyanoacrylate. Both membranes showed great potential for regenerating bone tissue, with higher bioactivity compared to gold standard (PTFE), which was used as positive control. In both, the stress-strain profile showed low stress at small strain. The fibrin sealant acted satisfactorily in the test, being highly recommended as a substitute for cyanoacrylate. (17)
Wound Healing Study / Latex Sap Gel: Study evaluated the effect of topical delivery of latex cream-gel in acute cutaneous wounds induced on back of rats. A cream-gel-based latex was applied on the wound bed: a dermo-epidermal excision of a round dorsal skin flap with 2.5 cm diameter. Results showed no statistically significant difference in percentage wound closure, histopathological findings, or reduction of wound area. Results showed the latex cream gel did not interfere in the healing of acute cutaneous wounds in rats. (18)
Wound Healing / Skin Abrasion Wound Model / 1% Latex Serum: Study evaluated the invitro viability and migratory/proliferative effects of latex serum from H. brasiliensis and compared it with a commercially available standard antiseptic solution and saline in experimental dermabrasion on rats, in measures of re-epithelization, neutrophilic infiltration, and quantification of crust and epidermis. The latex showed viability at 1% and 0.1% concentrations and migratory/proliferative activity at 0.1% concentrations. The non-toxic latex stimulated migration/proliferation of keratinocytes in vitro and significantly accelerated wound healing in animal excoriation models compared to chlorhexidine or saline. (19)
Reconstruction of Abdominal Wall Defect / Latex Membrane: Study compared seringueira latex membrane implant, with and without polilysine at 0.1% and marlex mesh on the repair of iatrogenic abdominal defects in Wistar rats. Results showed the seringueira's latex membrane, with or without polilysine 0.1%, when used on reconstruction of abdominal defects in rats is eliminated at 13.8 days after implantation, leaving a fiber base of reparation, similar to that observed after marlex mesh implantation. (20)
Latex Allergen /  Hev b I / Rubber Elongation Factor: A 1993 study identified a protein of 58 kd with an isoelectric point of 8.45 from raw latex and from latex gloves as the major allergen (Heb b I) completely blocking specific IgE antibodies of latex-sensitized subjects. The allergen is a noncovalent homotetramer molecule, identified by amino acid composition and sequence homologies of tryptic peptides as the rubber elongation factor found in natural latex of the rubber tree. Competitive immunoinhibition tests showed the starch powder covering finished gloves is the airborne carrier of the allergen, resulting in bronchial asthma on inhalation. The purified allergen can induce allergic reactions in the nanogram range. (Other studies have identified other latex allergens. See studies below) (21)
Prohevein / Major Latex Allergen: Proteins eluting from different natural rubber latex products can cause immediate type hypersensitivity reactions. Study purified and characterized three natural latex proteins in natural rubber latex that may represent significant allergens. A 20 kDa protein was identified as prohevein, a major protein in rubber tree H. brasiliensis; another a 30 kDa natural rubber latex protein was identified as hevamine; and a third, a previously undescribed natural rubber latex protein, showing high homology to several plant endo-1,2-ß-glucosidases. The purified prohevein elicited positive skin-prick test reactions in all six latex-allergic patients showing IgE to prohevein. The high frequency of IgE antibodies to prohevein suggests the protein is a major natural rubber latex allergen. (22)
Protein Allergen / Hev b 5: Proteins in commercial latex products from rubber tree H. brasiliensis can cause anaphylaxis in susceptible individuals, especially health care workers (HCW) and children with spina bifida. To identify latex allergens, study utilized IgE from serum of latex-allergic health care workers to screen a cDNA library from Hevea latex. Fifty-six % of spina bifida patients and 92% of HCW with latex allergy have IgE specific to the protein encoded by cDNA Hev b5.  Results suggest the antigen Hev B5 contains a major epitope for IgE-mediated reactions to H. brasiliensis latex products.  (23)
Natural Latex Membranes as Delivery System: Study evaluated the development of membranes of natural latex incorporated with C. sylvestris leaf derivative (ethanolic extract, diterpene concentrated fraction, and casearin J) and its invitro skin permeation and retention of C. sylvestris bioactive secondary metabolites (diterpenes and phenolic compounds). Membranes were developed mixing hydroethanolic solutions of C. sylvestris derivatives with latex and drying them in a dessicator. There was dermal penetration of phenolic compounds for ethanolic extract membrane and of casearin-like clerodane diterpenes for all membranes.  Results indicated great potential for therapeutic application as topical system for releasing C. sylvestris components. (24)
Rubber Tree Dust Exposure / Effect on Lung Function: A cross-sectional study evaluated the potential health effects related to wood dust from rubber tree exposure to respiratory and skin symptoms, asthma, and lung function among 103 workers (office workers and rubber tree furniture factory workers). Results showed increased risk of wheezing, nasal symptoms, and asthma in factory workers compared to office workers. There was a dose dependent increase in wheeze and skin symptoms in relation to dust level. Workers exposed to ethyl cyanacrylate glue had significantly increased risk of cough, shortness of breath, and nasal symptoms. There was dose dependent reduction in spirometric lung function with wood dust level. Results suggest furniture industry using rubber tree wood should implement appropriate exposure control measures. (25)
Rubber Leaf as Herbal Nutrition for Goats: Study evaluated the potency of rubber leaf as herbal nutrition for ruminant. Results showed fresh or withered rubber leaves are a source of high energy and protein feed for goats. Contents of total tannins and condensed tannins in fresh or withered leaves and branches indicated nutritive levels (i.e., 2% to 4% at DM base), and also indicated a potency as herbal medicine for goats. Withering of leaves during the day could increase its quality and potency as herbal nutrition. (26)
Use in Controlled Crush Injury of Sciatic Nerve in Rats /  Laser Therapy vs Natural Latex Protein: Study evaluated the effects of low-level laser therapy (LLLT, 15J/cm2, 780 nm wave length) and natural latex protein (P1, 0.1%) in sciatic nerve after crush injury (15 Kgf, axonotmesis) in rats. Results showed the application of LLLT and/or P1 improved the recovery from nerve crush injury. In the long term, the P1 protein was the better treatment used, since sole application of LLLT did not reach the same results, and both treatments applied together did not potentiate the recovery. (27)
Biochemical Composition of Latex: The latex from H. brasiliensis tree is today the only commercial source of natural rubber (NR), the cis-1,4-polyisoprene polymer, a strategic raw material. The latex is a colloidal dispersion where various micrometric objects, mainly rubber particles and lutoids are dispersed in cytoplasmic serum (C-serum). Rubber is most abundant, followed by C-serum, and lutoids. Composition of fresh latex is about 60% water, 35% of cis-1,4-polyisoprene and 5% non-isoprene molecules. Non-isoprenes are biochemical compounds, mostly proteins, lipids, carbohydrates, and minerals, in non-homogenous distribution in the fractions of latex. Although the non-isoprenes represent a minor part of the latex, they are likely behind the better mechanical properties of NR over the synthetic counterpart, and are responsible for the high variability of BR quality. This variability is a major drawback in the NR industry. (28)
Antimelanogenesis / Antioxidant / Cosmetic Application / Seed Oil: Major unsaturated fatty acid components of rubber seed oil are involved in biological activities, with potential for cosmeceutical applications. Study evaluated the fatty acid components of rubber seed oil and its cytotoxicity by sulforhodamine B assay and biological activities. Non-cytotoxic concentrations of rubber seed oil at 0.0001-0.1 mg/mL showed cell viability higher than 80% in B16-F10 melanoma cells and 3T3-L1 cells.  Concentration that inhibited cell viability at 50% (IC50) was 0.29 mg/mL in B16-F10 melanoma cells. Melanogenesis assay of seed oil at 0.1 mg/mL showed inhibitory effect on melanin content (46.24%), tyrosinase activity (53.85%), and tyrosinase-related protein-2 activity (66.01%). Antioxidant activity demonstrated cellular protective effect at 0.001 mg/mL with cell viability of 99.72%. Results suggest the potential of rubber seed oil as functional raw material for incorporation into personal care and cosmetic preparations. (see constituents above) (29)
Anti-Inflammatory / Attenuation of Lung Lesions /  Hev b 13: A protein from natural rubber latex (H. brasiliensis), named Hev b 13, demonstrated anti-inflammatory effects. Study evaluated the effects of Hev b 13 on inflammatory response and lung lesions of septic rats. Treatment with Hev b 13 resulted in significant decline in total and differential leukocytes and suppression of TNF-α and IL-6 production, associated with increase in IL-10 and IL-4 in plasma and lung tissue. It reduced morphological and pathological changes in the lungs, including neutrophil infiltration, edema, and alveolar thickening. Results suggest Hev b 13 exerts anti-inflammation effects and attenuates lung lesions. (30)
Gold Nanoparticles / Cytotoxicity and Genotoxicity Studies / Latex: Study reports on the green synthesis of gold nanoparticles using latex extracted from H. brasiliensis tree and evaluated their in vitro cytotoxicity and genotoxicity. Lowest concentration of AuNPs presented minimal cytotoxicity and genotoxicity. High concentrations of AuNPS promoted DNA damage and cell death via apoptosis. Results suggest low concentrations of the NPs have potential use in biological applications. (31)
Antifungal / C-Serum from Fresh Latex: Study evaluated C-serum from fresh latex of H. brasiliensis and rubber-processing effluent for possible antifungal activities and its relation to polyphenols. The
C-serum showed highest inhibition percentage in Rigidoporus microporus at 59% and lowest on Aspergillus niger at 16%, while the effluent only showed R. microporus inhibition at 10%. Phenolics was found higher in C-serum (1.745 g/ml GAE) than effluent (0.061 g/ml GAE). PPO (polyphenol oxidase) activities were detected at  0.0145 unit/µg in H. brasiliensis and 0.0092 unit/µg in effluent. The attribution of phenolics content towards antifungal activities may be important in regulation of disease prevention through breeding activities. PPO activity may also contribute to the understanding of its relation in protecting against tapping wound in rubber plant and browning of latex produced from the crop. (32)
Nutritive Value of Seed: Study evaluated the chemical composition of rubber seeds collected in Bangladesh. Decorticated rubber seeds yielded substantial amount of metabolizable energy and proximate components, and, like other unconventional feeds, might be a promising feed resource for livestock. (see constituents above) (34)
Photoprotective against UVB Irradiation / Antioxidant / Latex C-Serum: UVB radiation induces various adverse skin alterations ranging from simple photoaging to skin cancer.  Reactive oxygen species (ROS) were found to be related to cancer development and progression. Study evaluated  the protective effect of latex C-serum on male hairless (SKH-1) mice (Mus musculus) that were chronically exposed to UVB radiation. Latex C-serum prevented progression of actinic keratosis (AK) to squamous cell carcinoma lesions, and treatment significantly prevented abnormal skin development. Latex C-serum protected skin of mice against oxidative stress damage, increasing catalase (CAT) activity, regenerating glutathione (GSH) levels, lowering thiobarbituric acid-reactive species (TBARS) production and regenerating total antioxidant capacity (TAC) of the skin. Data indicate latex C-serum plays an important antioxidant and photoprotective role, preventing serious skin damage from UVB radiation. (35)
Hemmaglutination Activity / Lectin from Bark: Study of a protein isolated and purified from extracts of bark strips from mature rubber agglutinated erythrocytes from rabbits and all human blood types except AB. Proteolytic treatment of Hevea bark lectin (HBL) abolished haemagglutinin activity. The HBL showed maximum haemagglutination activity over the pH range 4.5-9.5 and heat stability up to 60°. (36)
Non-Apoptotic Cell Death in HepG2 / Latex C-Serum: Study evaluated the specific anti-proliferative effects of latex whole C-serum and its subfractions on human cancer cell lines. MTT assay revealed very low LC50s of 2.0 and 280 ng/ml, for DCS and DCP treatments. DCS was shown to be more potent compared to DCP in conferring anti-proliferative effects on cancer cell lines. Pre-heated C-serum fractions showed significantly diminished antiproliferative activity.  Results also suggested cell death was not promoted via the classical apoptotic signaling pathway. (37)
Anti-Proliferative Effect on Human Breast Cancer Epithelial Cells / Latex B-Serum: Study evaluated the specific anti-proliferation property of H. brasiliensis latex B-serum subfractions against human breast cancer epithelial cell lines MCF-7 and MDA-MB231. Results showed latex whole B-serum and DPB sub-fractions exerted specific antiproliferation activity against cancer-origin cells MDA-MB231 but little effect on non-cancer-origin cells. Anti-proliferative activity was diminished in pre-heated B-serum fractions. With low toxicity in BSLT (Brine Shrimp Lethality Test), results suggest potential use of B-serum sub-fractions in cancer treatment. (38)
Chemical and Nutritional Study of Seeds / Cyanide Content and Reduction Treatment: Study evaluated the chemical and nutritional composition of rubber seed. Protein content was 18%, and the most limiting amino acid was threonine, with a chemical score of 71.6. Iron, calcium, and phosphorus contents were 6.2, 109, and 429 mg/100 g, respectively.  Fat content was 48% with total energy value of 702 cal/100 g (2,948 Kj/100g. Total cyanide content in fresh seed was 130-230 mg/100g, 6% in free form and 94% as bound cyanide. The most effective treatment for reducing cyanide content was soaking in water for 20 hour, combined with one hour of cooking. Raw seed has low nutritive value and produced weight loss and death when fed to rats. Protein value of seed improved after treatment, reaching PER values close to traditional cereals such as corn. Results suggest the seed is a good source of energy, calcium, valine, isoleucine, phenylalanine and tyrosine; and a poor source of threonine, leucine, and lysine. High cyanide content s removed by treatment i.e., soaking in water, cooking or fat extraction. (40)

- Wild-crafted.
- Cultivated.

February 2024

                                                 PHOTOS / ILLUSTRATIONS
IMAGE SOURCE: Hevea brasiliensis / © Province of Davao Oriental / Image modified / Click on image or link to go to source page / DavaoOriental
OTHER IMAGE SOURCE: Hevea brasiliensis seeds / Luis Fernandez Garcia / CC BY-SA 2.5 es / Image modified / Click on image or link to go to source page / Wikipedia
OTHER IMAGE SOURCE: Hevea brasiliensis / Latex being collected from an incised rubber tree and a bucket of collected latex / Irvin Calicut / Public Domain / Image modified / Click on image or link to go to source page / Wikipedia
OTHER IMAGE SOURCE: Hevea brasiliensis flowers / Vinayaraj / CC BY-SA 4.0 International / Image modified / Click on image or link to go to source page / Wikipedia
OTHER IMAGE SOURCE: Hevea brasiliensis flowers / Vinayaraj / CC BY-SA 4.0 International / Image modified / Click on image or link to go to source page / Wikipedia
OTHER IMAGE SOURCE: Hevea brasiliensis leaves / Axel Boldt / Public Domain / Image modified / Click on image or link to go to source page / Feedipedia

Additional Sources and Suggested Readings
Hevea brasiliensis / KEW: Plants of the World Online
Hevea brasiliensis / Wikipedia
Rubber (Hevea brasiliensis) / Feedipedia: Animal Feed Resources Information System

Rubber Industry Profile / RISE: 30(2)-Para Rubber / PCAARRD'S Industry Strategic Science and Technology Plans
Rubber Industry / Province of Davao Oriental
Biomedical applications of natural rubber latex from the rubber tree Hevea brasiliensis / Nayrim Brizuela Guerra, Giovana Sant'Ana Pegorin, Miguel Henrique Boratto, Natan Roberto de Barros, Carolos Frederico de Oliveira Graeff, Rondinelli Donizetti Herculano / Materials Science and Engineering: C / 2021/ Vol 126: 112126
Phytochemical and antibacterial efficacy of Hevea brasiliensis / Sanjeet Kumar Singh, S Selva Kumar /  Journal of Chemical and Pharmaceutical Research, 2015; 7(12): pp 777-783
Increased vascular permeability, angiogenesis and wound healing induced by the serum of natural latex of the rubber tree Hevea brasiliensis / Ricardo Jose Mendonca, Vanessa Beatriz Mauricio, Larissa de Bortolli Teixeira, João Jose Lachat, Joaquim Coutinho-Netto / Phytotherapy Research, 2010; 24(5): pp 764-768 / DOI: 10.1002/ptr.3043
A Study on Hevea Brasiliensis for evaluation of phytochemical and pharmacological properties in Swiss Albino Mice / Md Salim Ahammed, Mst Monira Khanom, Md Eleas Kobir, Md Kayes Mahmud et al /
Discovery Phytomedicine, 2020; 7(2): pp 72-75 / DOI: 10.15562/phytomedicine.2019.122
Phytochemical, Antioxidant and Antimicrobial Activities of Hevea brasiliensis Leaves Extract / Kusumarn Noipha, Piyanuch Suwannarat, Supattra Prom-in, Titpawan Nakpheng /  HAYATI Journal of Biosciences, 2024; 31(2) / pISSN: 1978-3019 / eISSN: 2086-4094 / DOI: 10.4308/hjb.31.2.241-247
Anti-fungal effect of Hevea brasiliensis latex C-serum on Aspergillus niger / KMA Daruliza, KL Lam KL Yang, JT Priscila, E Sunderasan, MT Ong / European Review for Medical and Pharmacological Sciences, 2011; 15: pp 1027-1033
Anti-proliferation effect of Hevea brasiliensis latex B-serum on human breast epithelial cells / Yang Kok Lee, Lam Kit Lay, Mansor Sharif Mahsufi, Teoh Siang Guan, Sunderasan Elumalai, Ong Ming Thong / Pak J Pharm Scii., 2012; 25(3): pp 645-650
Anti-Candida albicans activity and brine shrimp lethality test of Hevea brasiliensis latex B-serum / KMA Daruliza, KL Yang, KL Lam, JT Priscilla, E Sunderasan, M T Ong / European Review for Medical and Pharmacological Sciences, 2011; 15: pp 1163-1171
Free-radical Scavenging properties and Cytotoxic Activity Evaluation of Latex C-serum from Hevea brasiliensis RRIM 600 / Leandra Ernst Kerche-Silva, Dalita Gomes Silva Morais Cavalcante, Aldo Eloizo Job et al / Free Radicals and Antioxidants, 2017; 7(1): pp 107-114 / DOI: 10.5530/fra.2017.1.16
Porosity effects of natural latex (Hevea brasiliensis) on release of compounds for biomedical applications  / MCR Miranda, FG Prezotti, FA Borges, NR Barros, BSF Cury, RD Herculano et al / Joournal of Biomaterials Science, Polymer Edition, 2017; 28(18): pp 2117-2130
LATEX AS A SIGNIFICANT SOURCE OF HEVEA BRASILIENSIS ALLERGEN EXPOSURE / David Kostyal PhD, Kelly Horton BS. Donald Beezhold PhD, Suzanne Lockwood CST, Robert G Hamilton PhD / Annals of Allergy, Asthma & Immunology, 2009; 103(4): pp 354-355 /
DOI: 10.1016/S1081-1206(10)60537-6
Comparative study of bone tissue accelerated regeneration by latex membranes from Hevea brasiliensisand Hancornia speciosa / Juliana Ferreira Floriano, Fausto Capuano Neto, Ligia Souza Lima Silveira da Mota et al / Biomedical Physics & Engineering Express, 2016; 2(4) / DOI: 10.1088/2057-1976/2/4/045007
Effect of Hevea brasiliensis latex sap gel on healing of acute skin wounds induced on the back of rats / Maria Vitoria Carmo Penhavel, Victor Henrique Tavares, Fabiana Pirani Carneiro, João Batista de Sousa / Rev. Col. Bras. Cir., 2016; 43(1) / DOI: 10.1590/0100-69912016001010
Healing effects of natural latex serum 1% from Hevea brasiliensis in an experimental skin abrasion wound model /  Marcel Nani Leite, Saulo Nani Leite, Guiilherme Ferreira Caetano,  Thiago Antonio Moretti de Andrade, Marcio Fronza, Marco Andrey Cipriani Frade / An Bras Dermatol, 2020; 95(4) /
DOI: 10.1016/j.abd.2019.12.003
Seringueira's latex membrane (Hevea brasiliensis) with and without polylysine 0,1% and marlex mesh for the reconstruction of iatrogenics abdominal wall defects in rats / Neusa Margarida Paulo, Flavia Gontijo de Lima, Juarez Tavora de Siqueira Junior,, Luis Fernando Froes Fleury, Fabiano Jose Ferreira de Sant'Ana, Alinne Cardoso Borges, Thalita da Costa Telles / Acta Cir. Bras, 2005; 20(4) /
DOI: 10.1590/S0102-86502005000400008
The rubber elongation factor of rubber trees (Hevea brasiliensis) is the major allergen in latex / Adam B Czuppon PhD, Z Chen PhD, Stefan Rennert MD, Thomas Engelke MD, Helmut E Meyer PhD, Markus Heber MS, Xaver Baur MD / Journal of Allergy and Clinical Immunology, 1993; 92(5): pp 690-697 /
DOI: 10.1016/0091-6749(93)90012-5
Prohevein from the rubber tree (Hevea brasiliensis) is a major latex allergen / H Alenius, N Kalkkinen, M Lukka, T Reunala, K Turjanmaa, S Mäkinen-Kiljunen, E Yip, T Palosuo / Clinical & Experimental Allergy, 1995; 25(7): pp 659-665 / DOI: 10.1111/j.1365-2222.1995.tb01114.x
Identification, Cloning, and Sequence of a Major Allergen (Hev b 5) from Natural Rubber Latex (Hevea brasiliensis) / Jaay E Slater, Thomas Vedvick, Ann Arthur-Smith, Diane E Trybul, Roy G O Kekwick / Protein Chemistry and Structure, 1996; 271(41): pp 25394-25399 / DOI 10.1074/jbc.271.41.25394
Natural membranes of Hevea brasiliensis latex as delivery system for Casearia sylvestris leaf components / Flavio A Carvalho, Helena S Uchina, Felipe A Borges, Marcia H Oyafuso, Rondinelli D Herculano, Maria P D Gremião, Andre G Santos / Re Bras. Farmacogn., 2018; 28(1) /
DOI: 10.1016/j.bjp.2017.10.007
Respiratory and skin effects of exposure to wood dust from the rubber tree Hevea brasiliensis
/ P Sripaiboonkij, W Phanprasit, M S Jaakkola / Occupational & Environmental Medicine, 66(7) /
DOI: 10.1136/oem.2008.042150
Analysis of Rubber Leaf (Hevea brasiliensis) Potency as Herbal Nutrition for Goats / Sri Wigati, Maksudi Maksudi, Abdul Latief / Proceedings of the 16th AAAP Annual Science Congress Vol II, Nov 2014; Gadjah Mada University, Indonesia
Application of a Low-Level Laser Therapy and the Purified Protein from Natural Latex (Hevea brasiliensis) in the Controlled Crush Injury of the Sciatic Nerve of Rats: A Morphological, Quantitative, and Ultrastructural Study /  Fernando Jose Dias, João Paulo Mardegan Issa, Ii-sei Watanabe et al / BioMed Research International, Volume 2013: Article ID 597863 / DOI: 10.1155/2013/597863
Chapter Seven - Biochemical composition of Hevea brasiliensis latex: A focus on the protein, lipid, carbohydrate and mineral contents / Celine Bottier / Advances in Botanical Research, 2020; Volume 93: pp 201-237 / DOI: 10.1016/bs.abr.2019.11.003
Protein from Hevea brasiliensis “Hev b 13” latex attenuates systemic inflammatory response and lung lesions in rats with sepsis / L A Araujo, P R Melo-Reis, F Mrue, C M Gomes et al / Braz, J. Biol., 2018; 78(2) / DOI: 10.1590/1519-6984.06316
Green synthesis of colloidal gold nanoparticles using latex from Hevea brasiliensis and evaluation of their in vitro cytotoxicity and genotoxicity / Natalia M Santos, Andressa S Gomes, Dalita GSM Cavalcante, Luis F Santos, Silvio R Teixeira / IET Nanobiotechnology, 2019; 13(3): pp 307-315 /
DOI: 10.1049/iet-nbt.2018.5225
Hevea brasiliensis / Plants For A Future
NUTRITIVE VALUE OF RUBBER SEED (Hevea brasiliensis) / Md Emran Hossain, Mohammad Hasanul Karim, Sanjiida Alam, Sabuj Kanti Nath /  Online Journal of Animal and Feed Research, 2015; 5(1): pp 18-21 / ISSN: 2228-7701
Antioxidant and photoprotective role of latex C-serum from Hevea brasiliensis during 15-week UVB irradiation in male hairless SKH-1 mice / Leandra E Kerche, Iriana M Carrara, Poliana C Marinello et al / Journal of Toxicology and Environmental Health, Part A; 2023; 86(22): pp 846-858 /
DOI: 10.1080/15287384.2023.2255885
A lectin from the bark of the rubber tree (Hevea brasiliensis) / Rapepun Wittsuwannakul, Dhirayos Wititsuwannakul, Chanchai Sakulborirug / Phytochemistry, 1998; 47(2): pp 183-187 /
DOI: 10.1016/S0031-9422(97)00329-4
Latex C-serum from Hevea brasiliensis induces non-apoptotic cell death in hepatocellular carcinoma cell line (HepG2) / K L Lam, K L Yang, E sunderasan, M T Ong / Cell Proliferation in Basic and Clinical Sciences, 2012; 45(6): pp 577-585 / DOI: 10.1111/j.1365-2184.2012.00841.x
Anti-proliferation effect of Hevea brasiliensis latex B-serum on human breast epithelial cells / Yang Kok Lee, Lam Kit Lay, Mansor Sharif Mahsufi et al / Pak. J. Pharm. Sci., 2012; 25(3): pp 645-650
Chemical components of the Hevea brasiliensis skim. / Tang LiChang, Wang Ning, Yao HaiPing, Yang Xian Hui et al / Chemistry and Industry of Forest Products, 2013; 33(1): pp 125-129 / pISSN: 0253-2417 / CABI Record No: 20133163625
Evaluation of chemical and nutritional characteristics of the seed of the rubber tree (Hevea brasiliensis) / C M Selle, E Gonzalez de Mejia, L G Elias, R Bressani / Arch Latinoam Nutr., 1983; 33(4): pp 884-901
Chapter 18 - Diseases of rubber trees: Malaysia as a case study / Murnita Mohmad Mahyudin, Aizat Shamin Noran et al / Forest Microbiology, 2023; Volume 3: pp 401-414

DOI: It is not uncommon for links on studies/sources to change. Copying and pasting the information on the search window or using the DOI (if available) will often redirect to the new link page. (Citing and Using a (DOI) Digital Object Identifier)

                                                            List of Understudied Philippine Medicinal Plants
                                          New plant names needed
The compilation now numbers over 1,300 medicinal plants. While I believe there are hundreds more that can be added to the collection, they are becoming more difficult to find. If you have a plant to suggest for inclusion, native or introduced, please email the info: scientific name (most helpful), local plant name (if known), any known folkloric medicinal use, and, if possible, a photo. Your help will be greatly appreciated.

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