Metabolite Profile of Cucurbitane-Type Triterpenoids of Bitter Melon (Fruit of Momordica charantia) and Their Inhibitory Activity against Protein Tyrosine Phosphatases Relevant to Insulin Resistance

Euonymus hamiltonianus Extract Improves Amnesia in APPswe/Tau Transgenic and Scopolamine-Induced Dementia Models

Dementia is a syndrome exhibiting progressive impairments on cognition and behavior beyond the normal course of aging, and Alzheimer's disease (AD) is one of the neurodegenerative diseases known to cause dementia. We investigated the effect of KGC07EH, the 30% ethanol extract of Euonymus hamiltonianus, against amyloid-β (Aβ) production and cognitive dysfunction in dementia models. KGC07EH was treated on Hela cells expressing the Swedish mutant form of amyloid precursor protein (APP), and the AD triple transgenic (3× TG) mice were given KGC07EH orally during 11-14 months of age (100 and 300 mg/kg/day). SH-SY5Y cell line was used to test KGC07EH on scopolamine-induced elevation of acetylcholinesterase (AChE) activity. ICR mice were intraperitoneally injected with scopolamine, and KGC07EH was administered orally (50, 100, and 200 mg/kg/day) for 4 weeks. KGC07EH treatment decreased Aβ, sAPPβ-sw, and sAPPβ-wt levels and APP protein expressions while sAPPα was increased in Swedish mutant-transfected HeLa cells. KGC07EH treatment also significantly reduced the accumulation of Aβ plaques and tau tangles in the brain of 3× TG mice as well as improving the cognitive function. In SH-SY5Y cells cultured with scopolamine, KGC07EH dose-dependently attenuated the increase of AChE activity. KGC07EH also improved scopolamine-induced learning and memory impairment in scopolamine-injected mice, and in their cerebral cortex and hippocampus, the expression levels of p-ERK, p-CREB, p-Akt, and BDNF were attenuated. KGC07EH inhibits APP processing and Aβ production both in vitro and in vivo, while enhancing acetylcholine signaling and cognitive dysfunction which are the major symptoms of dementia.

Momordica charantia Bioactive Components: Hypoglycemic and Hypolipidemic Benefits Through Gut Health Modulation

Momordica charantia (MC), a member of the Cucurbitaceae family, is well known for its pharmacological activities that exhibit hypoglycemic and hypolipidemic properties. These properties are largely because of its abundant bioactive compounds and phytochemicals. Over the years, numerous studies have confirmed the regulatory effects of MC extract on glycolipid metabolism. However, there is a lack of comprehensive reviews on newly discovered MC-related components, such as insulin receptor-binding protein-19, adMc1, and MC protein-30 and triterpenoids 3β,7β,25-trihydroxycucurbita-5,23(E)-dien-19-al, and the role of MC in gut microbiota and bitter taste receptors. This review offers an up-to-date overview of the recently reported chemical compositions of MC, including polysaccharides, saponins, polyphenolics, peptides, and their beneficial effects. It also provides the latest updates on the role of MC in the regulation of gut microbiota and bitter taste receptor signaling pathways. As a result, this review will serve as a theoretical basis for potential applications in the creation or modification of MC-based nutrient supplements.

New insights into the bioactive polysaccharides, proteins, and triterpenoids isolated from bitter melon (Momordica charantia) and their relevance for nutraceutical and food application: A review

The recent trend in infectious diseases and chronic disorders has dramatically increased consumers' interest in functional foods. As a result, the research of bioactive ingredients with potential for nutraceutical and food application has rapidly become a topic of interest. In this optic, the plant Momordica charantia (M. charantia) has recently attracted the most attention owing to its numerous biological properties including anti-diabetic, anti-obesity, anti-inflammatory, anti-cancers among others. However, the current literature on M. charantia has mainly been concerned with the plant extract while little is known on the specific bioactive compounds responsible for the plant's health benefits. Hence, the present review aims to provide a comprehensive overview of the recent research progress on bioactives isolated from M. charantia, focusing on polysaccharides, proteins, and triterpenoids. Thus, this review provides an up-to-date account of the different extraction methods used to isolate M. charantia bioactives. In addition, the structural features and biological properties are presented. Moreover, this review discusses the current and promising applications of M. charantia bioactives with relevance to the nutraceutical and food industries. The information provided in this review will serve as a theoretical basis and practical support for the formulation of products enriched with M. charantia bioactives.

Antiskin Aging Effects of Indole Alkaloid N-Glycoside from Ginkgo Fruit (Ginkgo biloba fruit) on TNF-α-Exposed Human Dermal Fibroblasts

Human skin aging has internal and external factors, both of which are characterized by TNF-α overproduction. Therefore, we aimed to identify a natural product that suppresses the damage that occurs in cutaneous dermal fibroblasts exposed to TNF-α. The protective effects of the indole alkaloid N-glycoside, ginkgoside B dimethyl ester (GBDE), isolated from ginkgo fruit (Ginkgo biloba fruit) were evaluated in TNF-α stimulated human dermal fibroblasts (HDFs). GBDE inhibited TNF-α-induced MMP-1 expression to 2.2 ± 0.1-fold (p < 0.01) and reversed the decrease in collagen levels to 0.4 ± 0.00-fold (p < 0.01) at 50 μM. The effect of GBDE was due to the suppression of the phospolylaton of MAPKs (ERK, 0.47 ± 0.05; JNK, 1.21 ± 0.07; p38, 0.77 ± 0.07-folds, p < 0.001) and Akt (0.14 ± 0.03-fold, p < 0.001) compared to the TNF-α group. GBDE also reduced the expression of COX-2 to 2.06 ± 0.12-fold (p < 0.001) and increased the expression of HO-1 to 10.64 ± 0.2-fold (p < 0.001). In addition, GBDE inhibited the expression of the pro-inflammatory cytokines (IL-8, 2.2 ± 0.0; IL-1β, 1.6 ± 0.0; IL-6, 2.0 ± 0.10-folds, p < 0.05). These results provide experimental evidence that GBDE can protect against skin damage, including aging.

Momordica charantia Extract Confers Protection Against Hypertension in Dahl Salt-Sensitive Rats

Hypertension is one of the main factors of cardiovascular disease worldwide and is strongly related to the overall mortality. High salt intake is a major risk factors for hypertension. Identifying functional foods that can help prevent mechanistic abnormalities mediating salt-induced hypertension is an issue of considerable nutraceutical and scientific interest. Dietary Momordica charantia may be an alternative approach to avoid salt-induced hypertension. Dahl salt-sensitive (DSS) rats were used to determine whether Momordica charantia water extracts (ME) exerts anti-hypertensive effects in the present study. ME gavage could significantly prevented the increase of blood pressure, blood urea nitrogen, creatinine, and urine protein-to-creatinine ratio of DSS rats. Metabolomics analysis indicated that high-salt diet induced abnormal amino acid metabolism was related to nitric oxide (NO) deficiency, but ME gavage could upregulate the activities of nitric oxide synthase, aspartate aminotransferase, argininosuccinate lyase, argininosuccinate synthase and restore endogenous synthesis of arginine and NO. Meanwhile, renal function was improved after ME gavage. Citrulline, as one of the important component in ME, could attenuate salt-induced hypertension by increasing endogenous synthesis of arginine and NO. Antioxidants in ME, such as phenolic compound, may avoid high-salt induced oxidative stress in DSS rats, which may be another mechanism by which ME prevented blood pressure increase. Thus, the present study indicated that feeding Momordica charantia could avoid high-salt-induced hypertension in DSS rats.

Weizhouochrones: Gorgonian-Derived Symmetric Dimers and Their Structure Elucidation Using Anisotropic NMR Combined with DP4+ Probability and CASE-3D

Natural product dimers have intriguing structural features and often have remarkable pharmacological activities. We report here two uncommon marine gorgonian-derived symmetric dimers, weizhouochrones A (1) and B (2), with indenone-derived monomers, that were isolated from the coral Anthogorgia ochracea collected from the South China Sea. These dimers are difficult targets for structure elucidation that solely relies upon conventional NMR data such as NOEs and J-couplings. Here, to explore the application of emerging methods on the structure elucidation of challenging molecules, we explored a number of different anisotropic and computational NMR approaches. The measurements of anisotropic NMR parameters of weizhouochrone A, including residual dipolar couplings (RDCs) and residual chemical shift anisotropy (RCSA), allowed us to successfully determine the planar structure and its relative configuration. This result was corroborated by a computational NMR analysis based on DP4+ probability and computer-assisted 3D structure elucidation (CASE-3D).

Momordica charantia L.-Diabetes-Related Bioactivities, Quality Control, and Safety Considerations

Momordica charantia L. (Cucurbitaceae), commonly known as bitter gourd or bitter melon, is widely cultivated in many tropical and subtropical regions of the world, where its unripe fruits are eaten as a vegetable. Apart from its culinary use, M. charantia has a long history in traditional medicine, serving as stomachic, laxative or anthelmintic, and, most notably, for the treatment of diabetes and its complications. Its antidiabetic properties and its beneficial effects on blood glucose and lipid concentrations have been reported in numerous in vitro and in vivo studies, but the compounds responsible for the observed effects have not yet been adequately described. Early reports were made for charantin, a mixture of two sterol glucosides, and the polypeptide p-insulin, but their low concentrations in the fruits or their limited bioavailability cannot explain the observed therapeutic effects. Still, for many decades the search for more reasonable active principles was omitted. However, in the last years, research more and more focused on the particular cucurbitane-type triterpenoids abundant in the fruits and other parts of the plant. This mini review deals with compounds isolated from the bitter gourd and discusses their bioactivities in conjunction with eventual antidiabetic or adverse effects. Furthermore, methods for the quality control of bitter gourd fruits and preparations will be evaluated for their meaningfulness and their potential use in the standardization of commercial preparations.

Structure determination, bitterness evaluation and hepatic gluconeogenesis inhibitory activity of triterpenoids from the Momordica charantia fruit

Triterpenoids are hypoglycemic substances and flavor components of Momordica charantia L., whether their bitterness correlated with hypoglycemic potential remain unknown. Thus, triterpenoids in M. charantia were isolated by phytochemical methods and identified by spectroscopic analysis. The bitterness levels and hypoglycaemic activity of isolated triterpenoids were evaluated by electronic tongue and hepatic gluconeogenesis assay. Eighteen triterpenoids including two new ones, Momordicoside Y and Z, were identified. Among the six identified bitter triterpenoids, karaviloside III, goyaglycoside C, and momordicoside F2 were bitterer than caffeine (P < 0.05), with caffeine equivalent (CE) values of 289.19, 4.32, and 41.24 mg CE/mg, respectively. Momordicoside Y, charantoside C, momordicoside F1, and momordicoside G could inhibit hepatic gluconeogenesis by 23.9%, 36.2%, 33.4%, 34.4% at 40 μM, respectively. These four compounds could interact with active site of phosphoenolpyruvate carboxykinase in molecular docking simulation. No correlation was observed between hepatic gluconeogenesis inhibitory activity and bitterness of triterpenoids.

Antidiabetic Medicinal Plants Used in Democratic Republic of Congo: A Critical Review of Ethnopharmacology and Bioactivity Data

Several studies have been conducted and published on medicinal plants used to manage Diabetes Mellitus worldwide. It is of great interest to review available studies from a country or a region to resort to similarities/discrepancies and data quality. Here, we examined data related to ethnopharmacology and bioactivity of antidiabetic plants used in the Democratic Republic of Congo. Data were extracted from Google Scholar, Medline/PubMed, Scopus, ScienceDirect, the Wiley Online Library, Web of Science, and other documents focusing on ethnopharmacology, pharmacology, and phytochemistry antidiabetic plants used in the Democratic Republic of Congo from 2005 to September 2021. The Kew Botanic Royal Garden and Plants of the World Online web databases were consulted to verify the taxonomic information. CAMARADES checklist was used to assess the quality of animal studies and Jadad scores for clinical trials. In total, 213 plant species belonging to 72 botanical families were reported. Only one plant, Droogmansia munamensis, is typically native to the DRC flora; 117 species are growing in the DRC and neighboring countries; 31 species are either introduced from other regions, and 64 are not specified. Alongside the treatment of Diabetes, about 78.13% of plants have multiple therapeutic uses, depending on the study sites. Experimental studies explored the antidiabetic activity of 133 plants, mainly in mice, rats, guinea pigs, and rabbits. Several chemical classes of antidiabetic compounds isolated from 67 plant species have been documented. Rare phase II clinical trials have been conducted. Critical issues included poor quality methodological protocols, author name incorrectly written (16.16%) or absent (14.25%) or confused with a synonym (4.69%), family name revised (17.26%) or missing (1.10%), voucher number not available 336(92.05%), ecological information not reported (49.59%). Most plant species have been identified and authenticated (89.32%). Hundreds of plants are used to treat Diabetes by traditional healers in DRC. However, most plants are not exclusively native to the local flora and have multiple therapeutic uses. The analysis showed the scarcity or absence of high-quality, in-depth pharmacological studies. There is a need to conduct further studies of locally specific species to fill the gap before their introduction into the national pharmacopeia.

Three Selected Edible Crops of the Genus Momordica as Potential Sources of Phytochemicals: Biochemical, Nutritional, and Medicinal Values

Momordica species (Family Cucurbitaceae) are cultivated throughout the world for their edible fruits, leaves, shoots and seeds. Among the species of the genus Momordica, there are three selected species that are used as vegetable, and for medicinal purposes, Momordica charantia L (Bitter melon), Momordica foetida Schumach (Bitter cucumber) and Momordica balsamina L (African pumpkin). The fruits and leaves of these Momordica species are rich in primary and secondary metabolites such as proteins, fibers, minerals (calcium, iron, magnesium, zinc), β-carotene, foliate, ascorbic acid, among others. The extracts from Momordica species are used for the treatment of a variety of diseases and ailments in traditional medicine. Momordica species extracts are reputed to possess anti-diabetic, anti-microbial, anthelmintic bioactivity, abortifacient, anti-bacterial, anti-viral, and play chemo-preventive functions. In this review we summarize the biochemical, nutritional, and medicinal values of three Momordica species (M. charantia, M. foetida and M. balsamina) as promising and innovative sources of natural bioactive compounds for future pharmaceutical usage.