Antidiabetic Evaluation of Momordica charantia L Fruit Extracts

Plant bioactive compounds and their mechanistic approaches in the treatment of diabetes: a review

Background

Diabetes mellitus (DM) is a growing disease across the world; diabetes is a complex metabolic disorder in which blood glucose concentration level increases and continue for a prolonged period due to a decrease secretion of insulin or action, resulting in the disorder of carbohydrate, lipid, and protein metabolism. The plant-related bioactive compounds have proven their efficacy with least toxicities and can be utilized for the disease treatment. Our objective is to elucidate the mechanism of action of plant bioactive compounds which can give future direction in diabetes treatment.

Main body

In this review paper, we briefly study more than 200 research papers related to disease and bioactive compounds that have therapeutic applicability in treatment. The plant contains many bio-active compounds which possess in vitro and in vivo anti-diabetic effect which may be responsible for the hypoglycaemic property by inhibiting the digestive enzyme i.e. alpha-amylase and alpha-glucosidase, by producing mimetic action of insulin, by reducing the oxidative stress, by showing antihyperglycemic activity and hypolipidemic activity, by inhibition of aldose reductase, and by increasing or enhancing glucose uptake and insulin secretion.

Conclusion

Our study revealed that terpenes, tannin, flavonoids, saponin, and alkaloids are important bioactive constituents for anti-diabetic activity. The mechanistic approach on alpha-glucosidase and alpha-amylase, hypolipidemic activity, and AR inhibitory action clear-cut explain the therapeutic applicability of these bioactive compounds in disease. Plants that contain these bioactive compounds can be good drug candidates for future research on diabetes treatment.

Antihyperglycemic and Antilipidemic Effects of the Ethanol Extract Mixture of Ligularia fischeri and Momordica charantia in Type II Diabetes-Mimicking Mice

The extract of the Momordica charantia fruit (MCE) is recognized as an alternative treatment for diabetes. The extract of Ligularia fischeri leaves (LFE) is traditionally used as a folk medicine for treating inflammatory diseases in Korea as well. In this study, we investigated the synergistic effect of MCE combined with LFE on antihyperglycemic and antihyperlipidemic potentials. Based on the α-glucosidase inhibitory effect and promotion of adipocyte differentiation in the 3T3-L1 cell line, the MLM was prepared with MCE:LFE (8:2 weight:weight). MLM showed the synergistic effects in the promotion of the glucose uptake rate, suppression of dipeptidyl peptidase-4 (DPP-4) mRNA expression, upregulation of an insulin receptor substrate and glucose transporter type-4 expression, and an increase in insulin-associated signaling in C2C12 cells. In addition, the efficacy of peroxisome proliferator-activated receptor-γ agonism and glucose uptake rate by MLM supplementation was significantly enhanced in vitro. Then, the antihyperglycemic and antihyperlipidemic effects of MCE, LFE, and MLM at the dose of 50, 100, and 200 mg/kg/day (n = 6 per each group) were determined in streptozotocin (STZ)-insulted mice fed an atherogenic diet (ATH) for 4 weeks. In addition, MLM (50, 100, and 200 mg/kg/day, n = 5 per each group) was supplemented in ATH-fed db/db mice for 10 weeks. Compared with MCE or LFE alone, MLM supplementation led to a more significant reduction of glucose levels in both STZ/ATH and db/db/ATH mice as well as lowered lipid profiles in STZ/ATH mice. In addition, the stimulation of islet of Langerhans regeneration was more pronounced by MLM supplementation in both mice models. In conclusion, antihyperglycemic and antihyperlipidemic effects were strengthened by the combined extracts of L. fischeri and M. charantia (MLM) in diabetes-mimicking mice.

Identification and Characterization of Phenylpropanoid Biosynthetic Genes and Their Accumulation in Bitter Melon (Momordica charantia)

Phenylpropanoids and flavonoids belong to a large group of secondary metabolites, and are considered to have antioxidant activity, which protects the cells against biotic and abiotic stresses. However, the accumulation of phenylpropanoids and flavonoids in bitter melon has rarely been studied. Here, we identify ten putative phenylpropanoid and flavonoid biosynthetic genes in bitter melon. Most genes were highly expressed in leaves and/or flowers. HPLC analysis showed that rutin and epicatechin were the most abundant compounds in bitter melon. Rutin content was the highest in leaves, whereas epicatechin was highly accumulated in flowers and fruits. The accumulation patterns of trans-cinnamic acid, p-coumaric acid, ferulic acid, kaempferol, and rutin coincide with the expression patterns of McPAL, McC4H, McCOMT, McFLS, and Mc3GT, respectively, suggesting that these genes play important roles in phenylpropanoid and flavonoid biosynthesis in bitter melon. In addition, we also investigated the optimum light conditions for enhancing phenylpropanoid and flavonoid biosynthesis and found that blue light was the most effective wavelength for enhanced accumulation of phenylpropanoids and flavonoids in bitter melon.

Accumulation of Charantin and Expression of Triterpenoid Biosynthesis Genes in Bitter Melon (Momordica charantia)

Charantin, a natural cucurbitane type triterpenoid, has been reported to have beneficial pharmacological functions such as anticancer, antidiabetic, and antibacterial activities. However, accumulation of charantin in bitter melon has been little studied. Here, we performed a transcriptome analysis to identify genes involved in the triterpenoid biosynthesis pathway in bitter melon seedlings. A total of 88,703 transcripts with an average length of 898 bp were identified in bitter melon seedlings. On the basis of a functional annotation, we identified 15 candidate genes encoding enzymes related to triterpenoid biosynthesis and analyzed their expression in different organs of mature plants. Most genes were highly expressed in flowers and/or fruit from the ripening stages. An HPLC analysis confirmed that the accumulation of charantin was highest in fruits from the ripening stage, followed by male flowers. The accumulation patterns of charantin coincide with the expression pattern of McSE and McCAS1, indicating that these genes play important roles in charantin biosynthesis in bitter melon. We also investigated optimum light conditions for enhancing charantin biosynthesis in bitter melon and found that red light was the most effective wavelength.

An Update Review on the Anthelmintic Activity of Bitter Gourd, Momordica charantia

Momordica charantia (Family: Cucurbitales), as known as bitter melon or gourd, is a daily consumption as food and traditional medicinal plant in Southeast Asia and Indo-China. It has been shown to possess anticancer, antidepressant, antidiabetic, anti-inflammatory, antimicrobial, antiobesity, antioxidant, and antiulcer properties. Its common phytochemical components include alkaloids, charantin, flavonoids, glycosides, phenolics, tannins, and terpenoids. This plant is rich in various saponins including momordicin, momordin, momordicoside, karavilagenin, karaviloside, and kuguacin, all of which have been reported to contribute to its remedial properties including antibacterial, antifungal, antiviral, and antiparasitic infections. Based on established literature on the anthelmintic activity of M. charantia and possible mode of action, this review article has attempted to compile M. charantia could be further explored for the development of potential anthelmintic drug.