- Sechium is a genus in the tribe Sicyoeae of the gourd family, Cucurbitaceae. The best known member is the edible and widely cultivated chayote.
- The fruit was first cultivated in Mesoamerica between souther Mexico and Honduras. It was one of several foods introduced to the Old World during the Columbian Exchange.
The fruit name derives from the Spanish word chayote, a derivate of the Nahuatl word chayohtli.
- The plant was first recorded by modern botanists in P. Browne's 1956 work, the Civil and Natural History of Jamaica. Swartz included it in 1800 in its current genus Sechium.
- Etymology: The genus name Sechium is likely an alteration, derived from Greek sikyos "cucumber". The species epithet edule means "edible".
Sayote is a tropical perennial vine, with stems climbing to 40 feet high. Rootstock is tuberous. Leaf petioles are 6 inches long. Leaves
are hairy, broadly cordate, entire or angled, 10 to 20 centimeters long. Flowers are staminate, yellowish to pale green, in long racemes. Pistillate flowers are solitary, corolla 12 to 17 millimeters. Fruit is pear-shaped, light green, and slightly wrinkled or with shallow, narrow, longitudinal grooves, in some forms set with soft spines. Seed is single, large, with a smooth testa, clinging to the flesh, protruding from the fruit apex.
Chayote is a
monoecious, vigorous, perennial herbaceous vine with a large tuberous root. Stem climbing or sprawling, longitudinally grooved, growing 10-15 m in a single season. Tendrils large, 2-5-branched. Leaves simple, spirally arranged; petiole 3-25 cm long; leaf-blade broadly ovate-circular in outline, 7-25 cm in diameter, base deeply cordate, 3-7-angular or lobed, acute, margins obtusely dentate, scabrid hairy. Inflorescences axillary racemes with small, greenish or cream, 5-merous flowers; hypanthium saucer-shaped, with 10 pouch-like nectaries on the bottom; male racemes with peduncle 6-30 cm long, 10-30-flowered; stamens 5, filaments united; female flowers usually solitary on short pedicels, in same axil as male; corolla ca. 2 mm in diameter; connate style and stigmas, forming a small head. Fruit a one-seeded fleshy berry, variable, commonly pear-shaped, 7-20 cm long, somewhat ribbed, smooth or shortly spiny, dark green to almost white; fruit stalk 2-3 cm long, pendent; pulp white or greenish-white. Seed solitary, ovoid to ellipsoid, 2.5-5 cm long, compressed, white, germinating within the fruit, usually while the fruit is still attached to the plant; in some genotypes seed-coat with fibres radiating into the flesh, in others obsolescent and the flesh fibreless. (44)
- Native to Belize, Mexico.
- Study yielded eight flavonoids
including three C-glycosyl and five O-glycosyl flavones. The leaves
gave the highest amount of flavonoids
- Phytochemical analysis of fruit (pulps and seeds) yielded alkaloids, flavonoids, saponins, and terpenoids.
(See study below) (10)
- Nutrient analysis of raw chayote per 100 g: (Proximates) water 94.24 g, energy 19 Kcal, carbohydrates 4.51 g, protein 0.82 g, total fat 0.13 g, cholesterol 0, dietary fiber 1.7 g, total sugars 1.66 g; (Vitamins) thiamin 0.025 mg, vitamin B6 0.076 mg, folates 93 µg, niacin 0.470 mg, pantothenic acid 0.249 mg, pyridoxine 0.076 mg, riboflavin 0.029 mg, vitamin A 0 IU, vitamin C 7.7 mg, vitamin E 0.12 mg, vitamin K 4.1 µg; (Electrolytes) sodium 2 mg, potassium 125 mg; (Minerals) calcium 17 mg, iron 0.34 mg, magnesium 12 mg, manganese 0.189 mg, phosphorus 18 mg, selenium 0..2 µg, zinc 0.74 mg; (Lipids) total saturated fatty acids 0.028 g,total monosaturated FA 0.010 g, total polyunsaturated FA 0.057 g, trans FA 0, cholesterol 0. (23)
- Study of dichlormethane extract of leaves isolated a mixture of trans-cinnamic acid (1a) and phenylacetic acid (1b) in 3:2 ratio, 3-octadecenoic acid (2), trilinolenin (3), and α-linoleic acid (4). (see study below) (30)
- Antiulcer, laxative, diuretic, antihypertensive, antioxidant.
- Studies have shown antioxidant, anti-hypertensive,
anti-epileptic, antimicrobial, anti-ulcer, vasorelaxant, membrane stabilizing, hepatoprotective, antihyperglycemic, hypouricemic, antifungal, catalytic, HDL-enhancing, cardioprotective, antilipogenesis properties.
Leaves and fruit.
- The fruit, tuber, stems and leaves are edible.
- Chayote fruit is usually used cooked. Raw chayote may be added to salads or salsas, most often marinated with lemon or lime juice, but as such, often considered unpalatable or rough in texture.
- Leaves are used in stews.
- Low in fiber, high in carbohydrate and caloric content.
- Fruit is laxative.
- Raw pulp of the fruit is soothing for skin rashes.
- Roasted leaves help in the suppuration of boils.
- Decoction of leaves drunk to relieve urinary retention and dysuria (burning when urinating) and to dissolve kidney stones.
(Lira 1988; Flores 1989; Yang and Walters 1992) (27)
- Fiber: Stem fibers used to make baskets and hats. In Ghana, used as binding material in construction of mud houses. (25)
Leaf ethanolic extracts and leaf and seed water extracts showed strong
inhibitory activity by B-carotene bleaching. Results may be potentially
exploited as biopreservatives and for health supplements or food to
alleviate oxidative stress. (1)
Extract studies produced a fall in blood pressure. The mechanisms
were not determined in the preliminary experiments. Further studies are indicated to delineate the mechanisms involved in decreased mean arterial pressure. (2)
Phytochemical study yielded eight flavonoids, including three C-glycosyl and five o-glycosyl flavones. Results showed the highest amount of flavonoids was in the leaves (35.0 mg/10 g of dried part), followed by roots (30.5 mg/10 g) and by stems (19.3 mg/10g). (3)
Alcoholic extracts of Sechium edule were tested against bacteria of clinical relevance as nosocomial pathogens. Results showed both fluid extract and tincture have very good antimicrobial efficacy against all strains of multiresistant staphylococci and enterococci and warrants further studies to isolate and identify the active principle/s. (4)
• Radiopharmaceutical Labeling and Uptake Effect:
The Effect of a Chayote (Sechium edule) Extracts (decocted and Macerated) on the Labeling of Blood Elements with Technetium- 9m and on the Biodistribution of the Radiopharmaceutical Sodium Pertechnetate in Mice: an In vitro and In vivo Analysis. The study suggests that some component of chayote extracts present an oxidant power to alter the biodistribution of Technitium-9m and cause alteration of the uptake in organs. (5)
• Antiulcer / Fruit:
Treatment with an ethanolic extract of fruit significantly protected against aspirin-induced ulceration with reduction of total acidity, free acidity, gastric output and increase pH of gastric secretion. (8).
Study yielded eight flavonoids, including three C-glycosyl and five o-glycosyl flavones. Aglycone moieties are represented by apigenin and luteolin; the sugar units by glucose, apiose and rhamnose.
• Antiepileptic / CNS Depressant Effect / Fruit:
An ethanol extract of fruits was evaluated for antiepileptic and CNS depressant effect in a rats. Results showed significant reduction of duration of various phases of convulsion in MES- and PTZ-induced convulsion. There was dose-dependent reduction of locomotor activity in the CNS depressant model. (9)
• Antibacterial / Food Borne Bacteria / Pulp:
Study evaluated various extracts of S. edule fruits (pulp and seed) against food borne bacteria. Chloroform and methanolic extracts exhibited antibacterial activity against most of the gram negative bacteria tested (E coli, S. typhimurium, and S. flexneri). (10)
• Antioxidant / RBC Membrane Stabilization:
Study evaluated the influence of chayote extract on the morphology of red blood cells and on the radiolabeling of blood elements with technetium-99m. Results showed the chayote extract has antioxidant compounds which could be responsible for alteration of RBC morphology without altering the radiolabeling of blood elements. (11)
• Antihypertensive / Vasorelaxant Effect:
Study evaluated the a hydroalcoholic extract from roots, including fractions and subfractions, on different hypertension models induced with angiotensin II. Results showed an antihypertensive and vasorelaxant effect probably due to an AG II antagonism activity. The AG II antagonistic effect could also have a calcium antagonist effect. The presence of cinnamic acid derivatives could be responsible for the angiotensin II and calcium antagonist effect. (12)
• Hepatoprotective / Carbon Tetrachloride Induced Injury / Fruits:
Study of ethanolic fruit extracts and its fractions showed significant hepatoprotective activity against CCl4 induced hepatotoxicity in rats in a dose dependent manner through it antioxidative effect on hepatocytes. (13)
• Effect on Plasmid Puc.9.1. DNA:
In this study, plasmid DNA was exposed to chayote extracts in the presence of stannous chloride and analyzed through agarose gel electrophoresis. Results showed the chayote extract was capable of damaging the DNA in the presence and/or absence of SnCl2. The effect might be due to generation of free radicals which might have induced lesions in the DNA molecule. (14)
• Antihyperglycemic / Fruit:
Study evaluated the preventive and therapeutic potentials of fruit juice of Benincasa hispida and Sechium edule in fructose and sucrose-sweetened beverages induced impaired glucose tolerance, oxidative stress and other IGT induced metabolic disturbances in rats. Results showed consumption of raw juice from vegetables may help ameliorate sweetened-beverages induced metabolic disturbances and impart health benefits to IGT individuals. (15)
• Lowers Uric Acid:
Study of sayote leaf extracts administered to hyperuricemic-induced rabbits showed a significant decrease of at least 25% of uric acid levels. Activity was attributed to flavonoids. No signs of toxicity or deaths occurred among the tested rabbits. (16)
• Antidiabetic / Fruits:
Study evaluated the effect of S. edule fruit extracts on alloxan induced diabetes in Wistar rats. Results showed significant decrease in blood glucose level, together with improvement of lipid profile. (17)
Study evaluated the antibacterial activities of methanol extracts of ten Cameroonian vegetables against a panel of twenty nine Gram negative bacteria including MDR strains. All extracts exhibited antibacterial activities. S. edule was one of three extracts which displayed the largest spectra of activity, with inhibitory effects against all 29 Gram-negative test bacteria. S. edule was also more active than chloramphenicol on at least one of the test MDR bacteria. (18)
Study evaluated the antimicrobial properties of Sechium edule alcoholic extracts against bacteria of clinical relevance as nosocomial pathogens. Results indicate that both fluid extract and tincture have very good antimicrobial efficacy against all strains of multiresistant staphylococci and enterococci. (19)
• Antibacterial / Antifungal:
Study of various extracts of aerial parts of D. esculentum and Sechium edule and the fruits of S. muricatum showed significant antimicrobial activity against a panel of 12 medically important microorganisms. All plant extracts showed antifungal activity, with 66% and 49% of the bioassays showing fungistatic and fungicidal activity, respectively. Two yeasts, Cryptococcus neoformans and Issatchenkia orientalis were susceptible to all extracts. In the antibacterial screening assays, 49% showed bacteriostatic activity, while 21% showed bactericidal activity. (21)
• Leaves Lowering River Water Bacterial Count: Study evaluated the effectivity of Sechium edule leaves extract in lowering the bacterial count of water sample from Wawa River for household use. Results showed upstream and midstream colony count showed no significant difference while the downstream bacterial count showed significant difference, indicating a positive result for downstream colony count. (24)
• Cardioprotective / Fruits: Study evaluated an ethanolic extract of fruits of Sechium edule for cardioprotective activity in rats challenged with s.c. administration of isoproterenol. Histopathology of hearts of ISO treated rats showed infiltration of inflammatory cells and muscle fiber changes suggesting of irreversible cell injury. Extract treated rats showed less degenerative changes compared to ISO-treated animals. (26)
• Antiproliferative on Tumor Cell Lines / Fruits: Study evaluated the anti-proliferative activity of crude ethanol extracts of fruits against three cancer cell lines viz., human cervical carcinoma (HeLa), mouse lung fibrosarcoma (L929), and mouse macrophage leukemia (P388). All varietal groups exhibited anti-proliferative activity against all tumour cell lines tested. (28)
• Inhibition of Lipogenesis / Stimulation of Lipolysis / Preventing of Fatty Liver / Polyphenol Extracts: Study investigated the effects and mechanisms of polyphenol extracts (SPE) of Sechium edule shoots in reducing lipid accumulation in oleic acid-treated HepG2 cells. Results showed a decrease in serum and hepatic lipid contents (e.g., triacylglycerol and cholesterol). Also, the water extracts and polyphenol extracts could decrease lipogenic relative enzymes (FAS, HMG-CoA reductase and SREBPs) via the AMPK signaling pathway, and increase the expression of CPT-1 and PPARa which are critical regulators of hepatic lipid metabolism. Study suggest potential for shoots as health food for prevention and treatment of fatty liver. (29)
• Alpha-Linoleic Acid and Trans-cinnamic Acid / Known Biologic Activities / Leaves: Study of dichlormethane extract of leaves isolated a mixture of trans-cinnamic acid (1a) and phenylacetic acid (1b) in 3:2 ratio, 3-octadecenoic acid (2), trilinolenin (3), and α-linoleic acid (4). Trans-cinnamic acid has been reported to show in-vitro antioxidant effects, antimicrobial activities, antifertility effect, and antihyperglycemic effect. α-Linolenic acid has been reported to possess hypotensive, cardioprotective, and hepatoprotective effects. The biologic activities of S. edule may be attributed to these two isolated compounds. (30)
• Anti-Inflammatory / Antibacterial / Fruits: Study evaluated three different extracts of S. edule plant for anti-inflammatory and antimicrobial activity. Using human red blood cell membrane stability model, the aqueous extract showed more protection from inflammation by reducing the precipitation of proteins present in human cell membrane. For in vitro antimicrobial activity, the methanol extract showed highest activity against Bacillus subtilis (MTCC 736) with MIC of 125 µg/ml. (31)
• Anti-Endothelial Dysfunction Activity / Roots: Endothelial dysfunction induced by Angiotensin II plays an important role in the pathogenesis of hypertension and is accompanied by prooxidative condition, which induces an inflammatory state, vascular remodeling, and tissue damage. Study evaluated the in vivo anti-endothelial activity of acetone fraction (rSe-ACE) of hydroalcoholic extract of S. edule roots. The rSe-ACE fraction at dose of 10 mg/kg was able to control hypertension, as well as the prooxidative and proinflammatory status in kidney as efficiently as losartan, returning mice to normotensive levels. The mixture yielded cinnamic acid as a major compound, and linoleic, palmitic, and myristic acids as the most abundant non-polar components. Results demonstrated rSe-ACE has anti-endothelial dysfunction activity and highlights the role of cinnamic acid and fatty acids. (32)
• Attenuation of QT-Prolongation in Induced-Hyperlipidemic Mice / Fruits: Study evaluated the effect of hydroalcoholic extract of S. edule fruits on lipid profile and ECG parameters in high fat-diet (HFD) induced hyperlipidemic mice. Treatment with SE extract (200 and 400 mg/kg) showed significant improvement in lipid profile and significantly normalized prolonged QT or QTc and RR interval and increased heart rate in HFD-challenged mice. (33)
• Reduction of Uric Acid Levels Through Inhibition of Xanthine Oxidase Activity / Leaves: Study evaluated the effect of chayote leaves flavonoid fraction on the level of uric acid and activity of xanthine oxidase (XO) in Sprague Dawley rats. Hyperuricemia was induced by potassium oxonate and broth block for 21 days. Chayote leaves flavonoid fraction contains apigenin, apigenin o-glucoside, and luteolin. Results showed significant reduction in xanthine oxidase activity in groups treated with flavonoid fraction (p<0.005). Best dose of flavonoid fraction affecting XO activity was 100 mg/200g body weight. The combination of FF and allopurinol can be more effective in decreasing uric acid levels through inhibition of xanthine oxidase. (34)
• Effect on Insulin Production and Malondialdehyde Level in STZ-Induced Rats / Fruits: Study evaluated the effect of Sechium edule ethanolic extract of fruits on insulin and malondialdehyde (MDA) levels in STZ-induced diabetic rats. Treatment with S. edule ethanol extract was unable to increase insulin, however treatment with 42 mg/kbw of ethanolic extract showed significantly decreased MDA levels on the liver but non-significant on kidney and pancreas. (35)
• Reduction of Blood Pressure in the Elderly / Chayote Juice: Study evaluated the effect of chayote juice on blood pressure in 13 elderly patients with hypertension, aged 60 - 90. Juice was prepared with peeled chayote (122 gms), boiled in 180 cc of water, and liquified in a blender to make juice, drunk 1 - 2 hours before a meal for 4 consecutive days. Results showed a median decrease in systolic pressure 30 mmHg and diastolic 10 mmHg (p value 0.001 <a 0.05). (36)
• Effect on HDL Cholesterol Level / Fruit: A randomized clinical trial evaluated the effect of chayote ethanol extract, fraction, and juice on HDL levels of male Wistar rats (Rattus novergicus sp.). The ethanol extract of chayote fruit (150 mg/kbw) showed highest average HDL levels compared to other groups, the effect attributed to presence of more bioactive compounds than the EA and n-hexane fraction. (37)
• Nephroprotective / Gentamicin, Potassium Dichromate and STZ Toxicity / Leaves: Study evaluated the aqueous extract of S. edule leaves for protective effect against gentamicin, potassium dichromate nephrotoxicity and streptozotocin-induced diabetic nephropathy in experimental animals. The S. edule extract (200 mg/kg) significantly (p<0.001) decreased the levels of blood urea, BUN, creatinine and significantly (p<0.001) increased the level of serum protein. Serum uric acid was also significantly decreased (p<0.001). There was improvement in kidney histology. Results showed a nephroprotective effect. (38)
• Chayote Flour-Based Biscuits: Study evaluated the potential and nutritional content of chayote flour-based biscuits. The process of making chayote flour involved washing, crushing, oven-drying, grounding, and sieving. The flour is mixed with baking soda and vanilla powder, sugar and eggs, and oven-baked at 160-175°C for 30-35 minutes. Proximate analysis per 100 g showed carbohydrates 57.66 g, fat 19.39g, protein 16.99g, water 6.68g, and ash 5.28g. Vitamins by % were vitamin C 13.97%, E 0.11%, and A 0.41%. Potassium was the highest mineral in the biscuit with 3,902 g/100g, followed by sodium 861, and calcium 665.g g/100g. Results suggest potential as a health food product. (39)
• Silver Nanoparticles / Antimicrobial / Fruit: Study reports on the cost effective, eco-friendly, green synthesis of silver nanoparticles from aqueous extract of Chayote squash. The AgNPs showed antimicrobial activity and catalytic activity toward the reduction of methylene blue. The reduction of MB by AgNPs is attributed to the electron relay effect. (40)
• Effect on Uric Acid, Oxidative Stress and Inflammatory Markers / Flavonoid Fraction of Leaves: Study evaluated the effect of flavonoid fraction of chayote leaves (FFCL) on uric acid, oxidative stress, and inflammatory markers in hyperuricemic Sprague Dawley
rats. Treatment with FFCL significantly reduced uric acid levels, oxidative stress marker malondialdehyde level, inflammatory marker tumor- necrosis factor-α level. The 100 mg/200 g BW/d FFCL decreased the levels more compared to 50 mg/200 g BW/d FFCL. (41)
• Formulation of Effervescent Granules: The S. edule fruit is traditionally used as an antiulcer herbal medicine. The active ingredients in S. edule that function as antiulcer are tannin, flavonoid and alkaloid compounds in the skin and fruit. Study evaluated the formulation of an alternative form of drug delivery using a mixture of ciitric acid, tartrate acid, and sodium bicarbonate for an effervescent granule. The formula that produced the best effervescent granules is formula III with a composition of 2:4:18 citric acid, tartaric acid, and sodium bicarbonate. (42)
• Photoprotection / Genoprotection Against UVA Irradiation in Keratinocytes / Fruit: Photoprotection is essential in preventing long-term deleterious effects of ultraviolet (UV) radiation, including skin cancer and photoaging. Study evaluated the effects of S. edule fruit extract in terms of photoprotection against UVA in primary human keratinocytes. The SEE protected keratinocytes against UVA-induced cytotoxicity, decreased intracellular amounts of reactive oxygen species (ROS), and reduced oxidatively induced DNA lesions after UVA exposure. It decreased induction of CPD lesions in UVA-irradiated keratinocytes and increased DNA repair of photoproducts. The SEE effects against UVA is a combination of antioxidant activity, reduction in DNA damage, and enhancement of DNA repair capacities. (43)