Botanical description of
Abstract
Momordica charantia L. is growing in many tropical and subtropical regions; the fruits of bitter melon are also gradually becoming popular for treating diabetes and associated diseases. Over 248 compounds belonging to the lipids, phenolics and terpenoids class are reported by diverse studies. However, M. charantia L. appears to be an inimitable species that synthesizes a diverse range of natural products in the fruits, leaves, stems and roots. The cucurbitane types of triterpenes exist in the various tissues of the plant in their aglycone as well as glycosylated forms. The bitter melon seems to exert their lipid lowering and antiobesity effects via several mechanisms like PPARs, LXRs, SREBPs, and Sirts mediated fat metabolism in various tissues, prevent adipocyte hypertrophy and visceral fat accumulation. M. charantia L. has been comprehensively studied worldwide for its therapeutic properties to treat a number of diseases like diabetes, dyslipidaemia, obesity, and certain cancers. This chapter apparently displays an encompassing literature review on vast potential of bitter melon as antiobesity agent and assembles data on complex phytochemistry.
Keywords
- obesity
- phytochemicals
- bitter melon
- cucurbitane type terpenoids
1. Introduction
The therapeutic significance of the plant is symbolized by the fruits which contain about half a dozen seeds per gram of the fresh fruit. As the name implies, the fruits are bitter and bitterness enhance with the level of maturity and hence earlier harvesting required to battle bitter taste. The leaves and young shoots of bitter melon recognized to be used in traditional medicine as an herbal tea. The range of pharmacological activities reported for bitter melon is rapidly increasing in recent years and its claimed uses and potential applications for cancer and other diseases have been extensively reviewed. Likewise, the range of medicinal claims range from diabetes, hypertension, obesity, cancer, as well as AIDS.
2. Plant profile
2.1 Botanical description
Plant parts | Description |
---|---|
Leaves | Broadly ovate to orbicular in outline, cordate, narrowly decurrent on to petiole, sparsely pubescent to densely villous on veins beneath, deeply palmately 3–7-lobed, lobes variously sinuate-dentate or lobulate. Leaf lamina 10 × 12.5 cm. |
Flowers | Flowers are monoecious and solitary. |
Fruits | Fruit 2.5–4.8 × 1.5–2.3 cm, ovoid-rostrate or ellipsoid, longitudinally ribbed and tuberculate, bright orange-red, dehiscent into 3 valves; fruit-stalk 3.4–15 cm long. |
Seeds | Seeds 8–11, 4.5–8 × 2–3.5 mm, enveloped in sticky red pulp, ovate-elliptic to oblong in outline; faces flattened, sculptured, with sinuate edges; margins grooved. |
Petiole | Petiole 0.5–7 cm long. |
2.2 Phytochemistry
The main constituents of bitter melon are triterpenoids, saponins, protein, polysaccharides, steroid, alkaloid, lipid, and phenolic compounds. Several bioactive compounds of
2.2.1 Triterpenoids
The most abundant phytochemical components of bitter melon fruits are the triterpenoids class of secondary metabolites, and are well-known for their bitterness and toxicity. These were divided in two types primarily the cucurbitane-type and to a less extent oleane type which may occur either in their glycosylated or aglycone forms. The sugar monomers as β-D-glucopyranosyl, β-D-allopyranosyl, β-D-xylopyranosyl occur in cucurbitane-type triterpenes either by their own as O-linked glycosides, or in different combinations as disaccharides or polysaccharides. The rare glycoside in these compounds was the 3-keto-glucoside [6]. An extremely large and certainly exhibited 193 number of cucurbitane-type triterpenes isolated from bitter melon having various pharmacological effects (Table 3) [7]. The fruits are predominance source of terpenoids with great deal of structural diversity but the leaves, stems and roots have also been shown to be good sources of these compounds [8].
Sr. No. | Bioactive compounds | Distribution | Pharmacological effects |
---|---|---|---|
1 | Triterpenoids | Leaves, stem, fruits | Chemo protective, anticancer, antioxidant, antidiabetic |
2 | Peptides and proteins | Seed | Antiviral, anti-tumor, immune suppressant, antimicrobial |
3 | Phenolics | Fruit and seed | Antioxidant, anti-inflammatory, immunostimulant |
4 | Saponin | Fruit, root, seed | Antihyperglycemic, hypolipidemic, antiviral, bacteriostatic |
5 | Polysaccharide | All parts of plant | Antioxidant, antidiabetic, immune enhancement, neuroprotective, antitumor |
6 | Lipid | Seed | Anti-tumor, antioxidant |
7 | Steroids | Fruit and pericarp | Antimicrobial |
Momordicosides A and B were isolated firstly from the seeds of bitter melon fruits; While, Momordicosides C, D and E were isolated as minor components of the seeds [9]. The study on the fruits of
The Goyaglycosides-a, −b, −c, −d, −e, −f, −g, and -h were isolated from the fresh fruits of Japanese
Another group of interesting triterpenoids are those known by their trivial names kuguacins. Kuguacins A-E and Kuguacins F-S were isolated from the roots and the leaves of bitter melon plant respectively [17]. Kuguacins II-VI was novel compounds isolated together with various other known compounds from the fruit of
2.2.2 Flavonoids and phenolic compounds
A number of phenolic compounds with many biological activities have been isolated from bitter melon including, coumaric, caffeic, and ferulic acids as well as the caffeic acid ester, chlorogenic acid, Benzoic, gallic and gentisic acid. The major flavonoids and phenolic acids in the dried leaves of bitter melon were also analyzed and found to be rutin, gentisic acid and coumaric acid [19]. While the phenolic acids and flavonoids as well as their glycosides can be readily extracted by water, their non-polar derivatives may be present in the oil components of the plant.
2.2.3 Other components
Other than the bioactive compounds, unsaturated fatty acids, alkaloids, amino acids minerals and vitamins are also present in bitter melon. The extracts of bitter melon shows nine kinds of unsaturated fatty. It has also been demonstrated that 12, 13 and 12 carbon fatty acids are found in young, mature, and senescent leaves of
3. Antiobesity and lipid lowering effects
The various experimental studies reported decrease in serum TC, TG and LDL-C concentrations and an increase in serum high density lipoprotein-cholesterol (HDL-C) for bitter melon by different authors. The action of bitter melon in lowering fat has been supported by plentiful studies, its effect on the level of serum FFAs have been contradictory with some authors showing reduction, some shown same level, and others reported an increased levels. For example, the serum FFAs concentration increased in obese rats treated with bitter melon shown by Chen et al. [21]. An increased level of TG and LDL-C in the serum that may arises due to either overproduction by the liver or defective removal from the circulation or the overall dyslipidaemia in diabetes. It is not clear why bitter melon increase the serum level of FFAs. It may facilitate fat mobilization due to the suppression of lipogenesis or lipid deposition. While other revealed
The findings of experimental research conclude that,
While further study revealed that, bitter melon supplementation into HFD notably suppressed the levels of fatty acid synthase (FAS), acetyl-CoA carboxylase-1 (ACC-1), lipoprotein lipase (LPL) and adipocyte fatty acid binding protein [25]. Water extract of
The methanolic extract of fruit of bitter melon showed antidiabetic and antihyperlipidemic action during different seasons of the year, this suggests that antidiabetic and hypolipidemic activity of
Moreover, bitter melon reduced the lipid accumulation during differentiation from a pre-adipocyte to adipocyte and down-regulated PPAR [32]. PPAR is considered the master regulator of adipogenesis during differentiation of pre-adipocyte to adipocyte [33]. Bitter melon juice inhibited adipocyte differentiation by reducing PPAR, SREBP, and perilipin mRNA gene expression and by increasing lipolysis in primary human adipocyte [34]. Several transcriptional regulatory factors like AMPK, PPAR, and PGC-1 regulate the mitochondrial biogenesis, which would be a possible way of increasing lipid metabolism and utilization in energy demanding cells and tissues [35]. PGC-1 stimulates mitochondrial biogenesis and respiration in multiple cell types and modulates biological programs normally associated with increased oxidative metabolism. Also decreased plasma level of TGs, cholesterol, and FFA in plasma of rats fed a HF diet revealed by bitter melon supplementation due to up regulation and activation of PGC-1 [36].
Bitter melon affects on various body organs to treat obesity and diabetes as [37]:
Liver
Increased β-oxidation
Increased PPAR-α and PPAR-gamma expression
Increased expression of the transcription coactivator PGC-1α
Decreased fatty acid synthesis
Decreased fat
Pancreas
Increased insulin secretion
Prevents cell damage
Increased PPAR-α and PPAR- gamma expression in skeletal muscle
Fat cells
Inhibited adipocyte hypertrophy
Inhibited adipocyte differentiation
Increased PPAR-gamma expression
Increased expression of the transcription co-activator PGC-1α
Decreased visceral fat mass
AMPK synchronized PPAR and PGC-1 activation encouraged most of the transcriptional signal to augment fatty acid oxidation and mitochondrial function [38]. Recent investigation also reported that increased hepatic AMPK p, AMPK, AMPK-2, and Sirt1 content in HF diet fed mice with supplementation of 1.2% bitter melon extract [39]. LXRs were first recognized as orphan members of the nuclear receptor plays an important role in lipid and cholesterol metabolism and oxidized derivatives of cholesterol act as ligands for the LXRs. A high cholesterol diet fed mice develop enlarged fatty livers, degeneration of liver cells, high cholesterol levels in liver, and impaired liver function by LXR knockout [40]. The
4. Toxic effects
The severe adverse reactions were not reported during the short term studies while extensive data on the potential toxic effect of bitter melon are not available. Bitter melon fruits are edible and assumed to be well tolerated, at the same time toxicological evidences were reported to discover its therapeutic potential for diabetes. The two cases of acute intoxication reported after taking bitter melon tea [43]. The fruit and seeds demonstrated greater toxicity than the leaf or aerial parts of the plant. Abdominal pain as a side effect has also been reported in some studies [44]. The antifertility and abortifacient effects of the
Several studies have been directed to reduce the bitterness of
5. Conclusion
References
- 1.
Subratty AH, Gurib-Fakim A, Mahomoodally F. Bitter melon: An exotic vegetable with medicinal values. Nutr Food Sci 2005;35:143–147 - 2.
Grover JK, Yadav SP. Pharmacological actions and potential uses of Momordica charantia : A review. J Ethnopharmacol 2004;93:123–132 - 3.
Fang EF, Ng TB. Bitter gourd ( Momordica charantia ) is a cornucopia of health: a review of its credited antidiabetic, anti-HIV, and anti-tumor properties. Curr Mol Med 2011;11(5):417–436 - 4.
Joseph B, Jini D. Antidiabetic effects of Momordica charantia (bitter melon) and its medicinal potency. Asian Pac J Trop Dis 2013;3(2):93–102 - 5.
Svobodova BB, Calhelha L, Heleno RC, Alves S, Walcott MJ. Bioactive properties and phenolic profile of Momordica charantia L. medicinal plant growing wild in Trinidad and Tobago. Ind Crop Prod 2017;95:365–373 - 6.
Akihisa T, Higo N, Tokuda H, Ukiya M, Akazawa H, Tochigi Y. Cucurbitane-type triterpenoids from the fruits of Momordica charantia and their cancer chemo-preventive effects. J Nat Prod 2007;70:1233–1239 - 7.
Karale P., Dhawale S. C., Karale M. A. Antiobesity potential and complex phytochemistry of Momodica charantia Linn. With promising molecular targets. Indian J Pharm Sci. 2020; 82(4): 548–561 - 8.
Chang CI, Chen CR, Liao YW, Cheng YW, Chen YC, Chou CH. Cucurbitane-type triterpenoids from Momordica charantia . J Nat Prod 2006;69(8):1168–1171 - 9.
Miyahara Y, Okasbe H, Yamauchi T. Studies on the constituents of Momordica charantia L. II. Isolation and characterization of minor seed glycosides, momordicosides C, D and E. Chem Pharm Bull 1981;29:1561–1566 - 10.
Okabe H, Miyahara Y, Yamauchi T. Structures of momordicosides F1, F2, G, I, K and L, novel cucurbitacins in the fruits of Momordica charantia L. Tetrahedron Lett 1982a; 23(1):77–80 - 11.
Li QY, Liang H, Chen HB, Wang B, Zhao YY.A new cucurbitane triterpenoid from Momordica charantia . Chin Chem Lett 2007; 18(7):843–845 - 12.
Nguyen XN, Phan VK, Chau VM, Ninh KB, Nguyen XC, Le MH. Cucurbitane-type triterpene glycosides from the fruits of Momordica charantia . Magn Reson Chem 2010; 48:392–396 - 13.
Okabe H, Miyahara Y, Yamauchi T. Structures of momordicine I, II and III. The bitter principles in the leaves and vines of Momordica charantia L. Chem. Pharm. Bull 1982b;30:4334–4340 - 14.
Murakami T, Emoto A, Matsuda H, Yoshikawa M. Medicinal foodstuffs XXI. Structures of new cucurbitane-type triterpene glycosides, goyaglycosides-a,-b, −c, −d, −e, −f, −g, and -h, and new oleanane-type triterpene saponins, goyasaponins I, II, and III, from the fresh fruit of Japanese Momordica charantia L. Chem. Pharm. Bull 2001;49:54–63 - 15.
Nakamura S, Murakami T, Nakamura J, Kobayashi H, Matsuda H, Yoshikawa M. Structures of new cucurbitane-type triterpenes and glycosides, karavilagenins and karavilosides, from the dried fruit of Momordica charantia L. in Sri Lanka. Chem Pharm Bull 2006;54:1545–1550 - 16.
Zhao GT, Liu JQ, Deng YY, Li HZ, Qiu MH. Cucurbitane-type triterpenoids from the stems and leaves of Momordica charantia . Fitoterapia 2014;95:75–82 - 17.
Yue J, Sun Y, Xu J, Cao J, Zhao Y. Cucurbitane triterpenoids from the fruit of Momordica charantia L. and their anti-hepatic fibrosis and anti-hepatoma activities. Phytochemistry 2019;157:21–27 - 18.
Yue J, Xu J, Cao J, Zhang X, Zhao Y. Cucurbitane triterpenoids from Momordica charantia L. and their inhibitory activity against α-glucosidase, α-amylase and protein tyrosine phosphatase 1B (PTP1B). J Funct Foods 2017;37:624–631 - 19.
Minh NP. Extraction of polyphenol in bitter melon ( Momordica charantia ). IJMRD 2014;1(4):115–125 - 20.
Krawinkel MB, Keding GB. Bitter gourd ( Momordica charantia ): A dietary approach to hyperglycemia. Nutr Rev 2006;64:331–337 - 21.
Chen Q, Chan LL, Li ET. Bitter melon ( Momordica charantia ) reduces adiposity, lowers serum insulin and normalizes glucose tolerance in rats fed a high fat diet. J Nutr 2003;133:1088–1093 - 22.
Wehash FE, Abpo-Ghanema II, Saleh RM. Some physiological effects of Momordica charantia and Trigonella foenum-graecum extracts in diabetic rats as compared with cidophage®. World Acad Sci Eng Technol 2012;64:1206–1214 - 23.
Nerurkar PV, Lee YK, Motosue M, Adeli K, Nerurkar VR. Momordica charantia (bitter melon) reduces plasma apolipoprotein B-100 and increases hepatic insulin receptor substrate and phosphoinositide-3 kinase interactions. Br J Nutr 2008;100:751–759 - 24.
Chen Q, Li ET. Reduced adiposity in bitter melon ( Momordica charanita ) fed rats is associated with lower tissue triglyceride and higher plasma catecholamines. Br J Nutr 2005;93:747–754 - 25.
Huang HL, Hong YW, Wong YH, Chen YN, Chyuan JH, Huang CJ. Bitter melon ( Momordica charantia L.) inhibits adipocyte hypertrophy an down regulates lipogenic gene expression in adipose tissue of dietinduced obese rats. Br J Nutr 2008;99:230–239 - 26.
Shih CC, Lin CH, Lin WL. Effects of Momordica charantia on insulin resistance and visceral obesity in mice on high-fat diet. Diabetes Res Clin Pract 2008;81:134–143 - 27.
Rajalakshmi A, Senthikumar B, Devi K. Antihyperglycemic and antihyperlipidemic effect of aqueous fruit extract of Momordica charantia against alloxan induced diabetic rats. Int J Pharma Res Sch 2013;2(4):54–60 - 28.
Fernandes NP, Lagishett CV, Panda VS, Suresh RN. An experimental evaluation of the antidiabetic and antilipidemic properties of a standardized Momordica charantia fruit extract. BMC Complement Altern Med 2007;7:29 - 29.
Kolawole OT and Ayankunle AA. Seasonal variation in the anti-Diabetic and hypolipidemic effects of Momordica charantia fruit extract in rats. European Journal of Medicinal Plants 2012;2(2):177–185 - 30.
Li X, Yi X, Shuang W, Qianchun D, Chun-Yan W, Xiang-Tao C et al. Novel bitter melon extracts highly yielded from supercritical extraction reduce the adiposity through the enhanced lipid metabolism in mice fed a high fat diet. Journal of Nutrition & Intermediary Metabolism 2016;6:26–32 - 31.
Wang J and Ho KR. The effects of Momordica charantia on obesity and lipid profiles of mice fed a high-fat diet. Nutrition Research and Practice 2015;9(5):489–495 - 32.
Popovich DG, Li L and Zhang W. Bitter melon ( Momordica charantia ) triterpenoid extract reduces preadipocyte viability, lipid accumulation and adiponectin expression in 3T3-L1 cells. Food and Chemical Toxicology 2010;48(6):1619–1626 - 33.
Wakabayashi KI, Okamura M, Tsutsumi S. The peroxisome proliferator-activated receptor gamm/retinoid X receptor alpha/heterodimer targets the histone modification enzyme PRSet7/Setd8 gene and regulates adipogenesis through a positive feedback loop. Molecular and Cellular Biology 2009;29(13):3544–3555 - 34.
Nerurkar PV, Lee YK, and Nerurkar VR. Momordica charantia (bitter melon) inhibits primary human adipocyte differentiation bymodulating adipogenic genes. BMC Complementary and Alternative Medicine 2010;10:34 - 35.
Puigserver P. and Spiegelman BM. Peroxisome proliferator activated receptor-alpha coactivator 1alpha (PGC-1α): transcriptional coactivator and metabolic regulator. Endocrine Reviews 2003;24(1):78–90 - 36.
Ching RHH, Yeung LOY, Tse IMY, Sit WH, Li ETS. Supplementation of bitter melon to rats fed a high-fructose diet during gestation and lactation ameliorates fructose-induced dyslipidemia and hepatic oxidative stress in male offspring. Journal of Nutrition 2011;141(9):1664–1672 - 37.
Md Ashraful Alam, Riaz Uddin, Nusrat Subhan, Md Mahbubur Rahman, Preeti Jain, and Hasan Mahmud Reza. Beneficial Role of Bitter Melon Supplementation in Obesity and Related Complications in Metabolic Syndrome. Journal of Lipids, 2015 ; 1–18 - 38.
Canto C. and Auwerx J. PGC-1α, SIRT1 and AMPK, an energy sensing network that controls energy expenditure. Current Opinion in Lipidology 2009;20(2):98–105 - 39.
Yu Y, Zhang XH, Ebersole B, Ribnicky D, Wang ZQ. Bitter melon extract attenuating hepatic steatosis may be mediated by FGF21 and AMPK/Sirt1 signaling in mice. Scientific Reports 2013;3:3142 - 40.
Peet DJ, Turley SD, Ma W. Cholesterol and bile acid metabolism are impaired in mice lacking the nuclear oxysterol receptor LXR-α Cell 1998;93(5):693–704 - 41.
Matsui S, Yamane T, Takita T, Oishi Y, Kobayashi-Hattori K. The hypocholesterolemic activity of Momordica charantia fruit ismediated by the altered cholesterol- and bile acidregulating gene expression in rat liver. Nutrition Research 2013;33(7):580–585 - 42.
Chikkavadaragudi RS, Vishwanath P, Prashant A, Rangaswamy C, Maduvanahalli NS, Hattur B. Fifty percent ethanolic extract of Momordica charantia inhibits adipogenesis and promotes adipolysis in 3T3-L1 pre-adipocyte cells. Rep Biochem Mol Biol 2017;6(1):23–32 - 43.
Hulin A. Intoxication aigue par Momordica charantia (sorrossi). A propos de deux cas (acute intoxication due toMomordica charantia (sorrossi). Study of two cases). Sem. Hop 1988;64:2847–2848 - 44.
Dans AM, Villarruz MV, Jimeno CA, Javelosa MA, Chua J, Bautista R. The effect of Momordica charantia capsule preparation on glycemic control in type 2 diabetes mellitus needs further studies. J Clin Epidemiol 2007;60:554–559 - 45.
Dutta PK, Chakravarty AK, Chowdhury US, Pakrashi SC. Vicine, a Favism-inducing toxin from Momordica charantia Linn. seeds. Indian J Chem 1981;20:669–671 - 46.
Deshaware S, Gupta S, Singhal RS, Joshi M, Variyar PS. Debittering of bitter gourd juice using β-cyclodextrin: Mechanism and effect on antidiabetic potential. Food Chem 2018;262:78–85 - 47.
Tan SP, Kha TC, Parks SE, Stathopoulos CE, Roach PD. Effects of the spray-drying temperatures on the physiochemical properties of an encapsulated bitter melon aqueous extract powder. Powder Technol 2015;281:65–75