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

Kaguacidine A: a novel spirohydantoin-containing cucurbitane glycoside from vines of Momordica charantia L

The spirohydantoin-containing cucurbitane-type triterpenoid, kaguacidine A (1), was isolated and purified from 95% ethanol extract of vines of Momordica charantia L. (Cucurbitaceae). Its unprecedented chemical structure, a spirohydantoin substituent at C-23 of cucurbitane, was elucidated by extensive spectroscopic analyses, including HRESIMS, IR, optical rotation, 1 D- and 2 D-NMR spectra. The possible biosynthetic pathway is deduced and may be attributed to the metabolic activity of microbial symbionts in M. charantia L. Compound 1 was evaluated for anti-inflammatory activity against LPS-induced NO production in RAW 264.7 cells and anti-proliferative activity against four cancer cell lines, including HEp-2, MCF-7, Hep-G2, and WiDr. Compound 1 showed moderate anti-inflammatory activity with an IC50 value of 18.5 ± 0.4 μg/mL and weak anti-proliferative activity against MCF-7, HEp-2, Hep-G2, and WiDr with IC50 values of >40, 33.8 ± 0.6, 31.0 ± 0.7, and 27.0 ± 0.7 μM, respectively.

The Effects of Momordica charantia on Type 2 Diabetes Mellitus and Alzheimer's Disease

T2DM is a complex metabolic disorder characterized by hyperglycemia and glucose intolerance. It is recognized as one of the most common metabolic disorders and its prevalence continues to raise major concerns in healthcare globally. Alzheimer's disease (AD) is a gradual neurodegenerative brain disorder characterized by the chronic loss of cognitive and behavioral function. Recent research suggests a link between the two diseases. Considering the shared characteristics of both diseases, common therapeutic and preventive agents are effective. Certain bioactive compounds such as polyphenols, vitamins, and minerals found in vegetables and fruits can have antioxidant and anti-inflammatory effects that allow for preventative or potential treatment options for T2DM and AD. Recently, it has been estimated that up to one-third of patients with diabetes use some form of complementary and alternative medicine. Increasing evidence from cell or animal models suggests that bioactive compounds may have a direct effect on reducing hyperglycemia, amplifying insulin secretion, and blocking the formation of amyloid plaques. One plant that has received substantial recognition for its numerous bioactive properties is Momordica charantia (M. charantia), otherwise known as bitter melon, bitter gourd, karela, and balsam pear. M. charantia is utilized for its glucose-lowering effects and is often used as a treatment for diabetes and related metabolic conditions amongst the indigenous populations of Asia, South America, India, and East Africa. Several pre-clinical studies have documented the beneficial effects of M. charantia through various postulated mechanisms. Throughout this review, the underlying molecular mechanisms of the bioactive components of M. charantia will be highlighted. More studies will be necessary to establish the clinical efficacy of the bioactive compounds within M. charantia to effectively determine its pertinence in the treatment of metabolic disorders and neurodegenerative diseases, such as T2DM and AD.

An overview of bitter compounds in foodstuffs: Classifications, evaluation methods for sensory contribution, separation and identification techniques, and mechanism of bitter taste transduction

The bitter taste is generally considered an undesirable sensory attribute. However, bitter-tasting compounds can significantly affect the overall flavor of many foods and beverages and endow them with various beneficial effects on human health. To better understand the relationship between chemical structure and bitterness, this paper has summarized the bitter compounds in foodstuffs and classified them based on the basic skeletons. Only those bitter compounds that are confirmed by human sensory evaluation have been included in this paper. To develop food products that satisfy consumer preferences, correctly ranking the key bitter compounds in foodstuffs according to their contributions to the overall bitterness intensity is the precondition. Generally, three methods were applied to screen out the key bitter compounds in foods and beverages and evaluate their sensory contributions, including dose-over-threshold factors, taste dilution analysis, and spectrum descriptive analysis method. This paper has discussed in detail the mechanisms and applications of these three methods. Typical procedures for separating and identifying the main bitter compounds in foodstuffs have also been summarized. Additionally, the activation of human bitter taste receptors (TAS2Rs) and the mechanisms of bitter taste transduction are outlined. Ultimately, a conclusion has been drawn to highlight the current problems and propose potential directions for further research.

A Review of Traditional Uses, Phytochemistry and Pharmacological Properties of Some Vietnamese Wound-Healing Medicinal Plants

Wound healing is a sophisticated process that results in the repair of damaged tissues. Any impairment to this process can lead to non-healing (chronic) wounds. Since these can cause a massive burden on the healthcare system, alternative therapies that promote wound healing should be considered. Therapies of natural origins that are safe and with no adverse side effects are especially promising. Vietnam, a tropical-climate country, has many medicinal plants that possess the potential for healing wounds. This report explores the use of some common plants used in Traditional Vietnamese medicine and their molecular mechanisms.

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.

Cucurbitane-type triterpenoids from the vines of Momordica charantia and their anti-inflammatory, cytotoxic, and antidiabetic activity

Phytochemical investigation of the ethanol extract from wild Momordica charantia vines has resulted in isolation of seven cucurbitane-type triterpenoids, including six undescribed compounds, kuguaovins H‒M, and the known compound, momordicoside K. The structures of the isolated compounds were elucidated on the basis of spectroscopic analyses, including 1D and 2D NMR, and MS experiments. The chemical structure of momordicoside K was determined for the first time by X-ray crystallographic analysis and its absolute configuration assigned. The cytotoxicity against four human tumor cell lines and anti-inflammatory activities on LPS-stimulated RAW264.7 macrophages were evaluated. Of the isolates, kaguaovin L exhibited potential cytotoxicity against MCF-7, HEp-2, Hep-G2, and WiDr cancer cell lines and showed moderate anti-NO production activity. In addition, kuguaovins H and J also showed the stimulatory effect of GLP-1 secretion on the murine intestinal secretin tumor cell line (STC-1).

Charantoside L, A New Cucurbitane-Type Glycoside from Momordica charantia L. with α-Glucosidase Inhibitory Activities

A new cucurbitane-type glycoside (1) and two known compounds (2-3) were isolated from the ethanol extract of the fruits of Momordica charantia L. Their chemical structures were determined as (19 S,23 E)-5 β­,19-epoxy-19-methoxycucurbita-6,23-diene-3 β,25-diol 3 -O-β-D-allopyranoside (1), goyaglycoside d (2), and (19 S,23 E)-5 β,19-epoxy-19-methoxycucurbita-6,23-diene-3 β,25-diol (3) on the basis of the extensive spectroscopic methods, including 1D, 2D NMR, HRESIMS, and in comparison with the reported data. Compounds 1 to 3 were evaluated for α-glucosidase inhibitory effects. Compounds 1 and 2 showed anti α-glucosidase activity with IC50 values of 134.12 ± 11.20 and 163.17 ± 13.71 µM, respectively, compared with the positive control, acarbose, IC50 160.99 ± 14.30 μM. Compounds 2 and 3 were first isolated from plant M. charantia growing in Vietnam.

Antioxidants profile of Momordica charantia fruit extract analyzed using LC-MS-QTOF-based metabolomics

Momordica charantia fruit is claimed to have healthy benefit. Despite this potential claim, the phytochemical study of this fruit is still lacking. Thus, this study aimed to evaluate the antioxidants profile of Momordica charantia (Cucurbitaceae) fruit. The antioxidant activity of the ethanolic extracts of various polarities was evaluated and the metabolites that are responsible for its activity were identified using metabolomics approach. Six different mixture of ethanol in water that are 0%, 20%, 40%, 60%, 80%, and 100% (v/v) was extracted using dveseeded fruit sample. Liquid chromatography-mass spectrometry-quadrupole time of flight and multivariate data analysis was used to identify the metabolites that were either antioxidants or pro-oxidants. The 80% ethanol extract exhibited the most antioxidant activity when tested in both 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) antioxidant assays. This extract showed the most intense LC-MS signals represented to ascorbic acid, margarolic acid, brevifolincarboxylic acid, quercetin 3-O-glycoside, kuguacin H, cucurbitacin E, 3-malonylmomordicin I, and goyaglycoside G correlating to the anti-oxidant activity. This study reports for the first time the existence of brevifolincarboxylic acid in this fruit, and the antioxidant activity of 3-malonylmomordicin I and goyaglycoside G. In addition, the loading plots revealed the unknown compounds possessing the antioxidant activity which are potential to be isolated in the future study.

Inhibitory Effects of Cucurbitane-Type Triterpenoids from Momordica charantia Fruit on Lipopolysaccharide-Stimulated Pro-Inflammatory Cytokine Production in Bone Marrow-Derived Dendritic Cells

The bitter melon, Momordica charantia L., was once an important food and medicinal herb. Various studies have focused on the potential treatment of stomach disease with M. charantia and on its anti-diabetic properties. However, very little is known about the specific compounds responsible for its anti-inflammatory activities. In addition, the in vitro inhibitory effect of M. charantia on pro-inflammatory cytokine production by lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells (BMDCs) has not been reported. Phytochemical investigation of M. charantia fruit led to the isolation of 15 compounds (1-15). Their chemical structures were elucidated spectroscopically (one- and two-dimensional nuclear magnetic resonance) and with electrospray ionization mass spectrometry. The anti-inflammatory effects of the isolated compounds were evaluated by measuring the production of the pro-inflammatory cytokines interleukin IL-6, IL-12 p40, and tumor necrosis factor α (TNF-α) in LPS-stimulated BMDCs. The cucurbitanes were potent inhibitors of the cytokines TNF-α, IL-6, and IL-12 p40, indicating promising anti-inflammatory effects. Based on these studies and in silico simulations, we determined that the ligand likely docked in the receptors. These results suggest that cucurbitanes from M. charantia are potential candidates for treating inflammatory diseases.

Lipidomics-Based Comparison of Molecular Compositions of Green, Yellow, and Red Bell Peppers

Identifying and annotating the molecular composition of individual foods will improve scientific understanding of how foods impact human health and how much variation exists in the molecular composition of foods of the same species. The complexity of this task includes distinct varieties and variations in natural occurring pigments of foods. Lipidomics, a sub-field of metabolomics, has emerged as an effective tool to help decipher the molecular composition of foods. For this proof-of-principle research, we determined the lipidomic profiles of green, yellow and red bell peppers (Capsicum annuum) using liquid chromatography mass spectrometry and a novel tool for automated annotation of compounds following database searches. Among 23 samples analyzed from 6 peppers (2 green, 1 yellow, and 3 red), over 8000 lipid compounds were detected with 315 compounds (106 annotated) found in all three colors. Assessments of relationships between these compounds and pepper color, using linear mixed effects regression and false discovery rate (<0.05) statistical adjustment, revealed 11 compounds differing by color. The compound most strongly associated with color was the carotenoid, β-cryptoxanthin (p-value = 7.4 × 10⁻⁵; FDR adjusted p-value = 0.0080). These results support lipidomics as a viable analytical technique to identify molecular compounds that can be used for unique characterization of foods.

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

Qualitative analysis of cucurbitane-type triterpenoids of bitter melon (fruit of Momordica charantia L.) using ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry revealed 27 promising cucurbitane-type triterpenoids, and LC/MS-guided chemical analysis of M. charantia fruit extract led to the isolation and structural characterization of 22 cucurbitane-type triterpenoids (1-22), including 8 new cucurbitane-type triterpenoidal saponins, yeojoosides A-H (1-8). The structures of the new compounds (1-8) were elucidated by spectroscopic methods, including 1D and 2D NMR and high-resolution electrospray ionization mass spectrometry. Their absolute configurations were assigned by quantum chemical electronic circular dichroism calculations, chemical reactions, and DP4+ analysis using gauge-including atomic orbital NMR chemical shift calculations. All isolated compounds (1-22) were examined for inhibitory activity against protein tyrosine phosphatases relevant to insulin resistance. Nine compounds (7, 8, 9, 11, 14, 15, 19, 20, and 21) showed selective inhibitory effects of over 70% against PTPN2. The present results suggested that these compounds would be potential antidiabetic agents.

Cucurbitane-Type Triterpene Glycosides from Momordica charantia and Their α-Glucosidase Inhibitory Activities

Ten cucurbitane-type triterpene glycosides, including five new compounds named charantosides H (1), J (2), K (3), momorcharacoside A (4), goyaglycoside-L (5), and five known compounds (6-10), were isolated from the EtOAc extract of Momordica charantia fruits. The chemical structures of these compounds were identified by 1D and 2D NMR and HRESIMS spectroscopic analyses. Configurations of new compounds were determined by ROESY correlations and comparison of their ¹³C NMR data with literature reported values. All compounds were evaluated for their inhibition against α-glucosidase, in which compounds 2, 5, 7, 8, 9 showed moderate inhibitory activities with IC₅₀ values ranging from 28.40 to 63.26 μM comparing with the positive control (acarbose, IC₅₀ 87.65 ± 6.51 μM).

Cucurbitane-Type Triterpenoids from the Vines of Momordica charantia and Their Anti-inflammatory Activities

Seven new cucurbitane-type triterpenoids, kuguaovins A-G (1-7), and five known ones were isolated from the rattans of wild Momordica charantia. Their structures were established by spectroscopic data analyses, including 1D and 2D NMR, IR, and MS techniques. The absolute configurations of the cucurbitanes were determined from NOESY data and partially by X-ray crystallographic analysis. In pharmacological studies, compounds 1-7 and 9-12 exhibited weak anti-inflammatory effects (IC50 = 15-35 μM), based on an anti-NO production assay.

Immunomodulatory Activity of Momordica charantia L. (Cucurbitaceae) Leaf Diethyl Ether and Methanol Extracts on Salmonella typhi-Infected Mice and LPS-Induced Phagocytic Activities of Macrophages and Neutrophils

Infections due to Salmonella strains constitute one of the major health problems in humans, particularly in Africa. The use of traditional herbs has proven effective in reducing the incidence of infection in some high-risk groups. To assess the effects of Momordica charantia leaf extracts that influence blood infection, an in vitro study of the effect on macrophages and neutrophils and treatment of mouse model of S. typhi infection was done. Methanol and diethyl ether extracts were concerned by this study. In vitro study was to assess the effects of extracts on phagocytosis, and related intracellular killing mechanisms of macrophages were examined. Later, mobilization of leukocytes and production of antibodies against S. typhi were measured followed by quantitating cultures evaluation of the blood infection of orally inoculated mice with S. typhi. Ingestion or attachment of carbon particles, production of superoxide anion, nitric oxide, and that of lysosomal acid phosphatase by macrophages and neutrophils were significantly increased by methanol and diethyl extracts at concentrations ranging from 40 μg/ml to 640 μg/ml. Antibody titer and mobilization of leukocytes, particularly lymphocytes against S. typhi, were highly increased by both methanol and diethyl extracts at concentrations of 500 and 1000 mg/kg. At the same time, the extracts have reduced the rate of blood colonization in mice inoculated with 10⁸ CFU of S. typhi for 28 days. Reduction in blood colonization or infection rates was similar for the levamisole mice group. The results of this study should prove that the leaves of Momordica charantia are useful for the treatment of infections by Salmonella strains and for the assessment of drugs for therapeutic intervention.

Allylic hydroxylation of triterpenoids by a plant cytochrome P450 triggers key chemical transformations that produce a variety of bitter compounds

Cucurbitacins are highly oxygenated triterpenoids characteristic of plants in the family Cucurbitaceae and responsible for the bitter taste of these plants. Fruits of bitter melon (Momordica charantia) contain various cucurbitacins possessing an unusual ether bridge between C5 and C19, not observed in other Cucurbitaceae members. Using a combination of next-generation sequencing and RNA-Seq analysis and gene-to-gene co-expression analysis with the ConfeitoGUIplus software, we identified three P450 genes, CYP81AQ19, CYP88L7, and CYP88L8, expected to be involved in cucurbitacin biosynthesis. CYP81AQ19 co-expression with cucurbitadienol synthase in yeast resulted in the production of cucurbita-5,24-diene-3β,23α-diol. A mild acid treatment of this compound resulted in an isomerization of the C23-OH group to C25-OH with the concomitant migration of a double bond, suggesting that a nonenzymatic transformation may account for the observed C25-OH in the majority of cucurbitacins found in plants. The functional expression of CYP88L7 resulted in the production of hydroxylated C19 as well as C5-C19 ether-bridged products. A plausible mechanism for the formation of the C5-C19 ether bridge involves C7 and C19 hydroxylations, indicating a multifunctional nature of this P450. On the other hand, functional CYP88L8 expression gave a single product, a triterpene diol, indicating a monofunctional P450 catalyzing the C7 hydroxylation. Our findings of the roles of several plant P450s in cucurbitacin biosynthesis reveal that an allylic hydroxylation is a key enzymatic transformation that triggers subsequent processes to produce structurally diverse products.

The Role of Momordica charantia in Resisting Obesity

Momordica charantia (M. charantia), commonly known as bitter gourd, bitter melon, kugua, balsam pear, or karela, is a tropical and sub-tropical vine belonging to the Cucurbitaceae family. It has been used to treat a variety of diseases in the traditional medicine of China, India, and Sri Lanka. Here, we review the anti-obesity effects of various bioactive components of M. charantia established at the cellular and organismal level. We aim to provide links between various bioactive components of M. charantia and their anti-obesity mechanism. An advanced search was conducted on the worldwide accepted scientific databases via electronic search (Google Scholar, Web of Science, ScienceDirect, ACS Publications, PubMed, Wiley Online Library, SciFinder, CNKI) database with the query TS = “Momordica charantia” and “obesity”. Information was also obtained from International Plant Names Index, Chinese Pharmacopoeia, Chinese herbal classic books, online databases, PhD and MSc dissertations, etc. First, studies showing the anti-obesity effects of M. charantia on the cells and on animals were classified. The major bioactive components that showed anti-obesity activities included proteins, triterpenoids, saponins, phenolics, and conjugated linolenic acids. Their mechanisms included inhibition of fat synthesis, promotion of glucose utilization, and stimulation of auxiliary lipid-lowering activity. Finally, we summarized the risks of excessive consumption of M. charantia and the application. Although further research is necessary to explore various issues, this review establishes the therapeutic potential of M. charantia and it is highly promising candidate for the development of anti-obesity health products and medicines.

Identification of chemotypes in bitter melon by metabolomics: a plant with potential benefit for management of diabetes in traditional Chinese medicine

INTRODUCTION

Bitter melon (Momordica charantia, Cucurbitaceae) is a popular edible medicinal plant, which has been used as a botanical dietary supplement for the treatment of diabetes and obesity in Chinese folk medicine. Previously, our team has proved that cucurbitanes triterpenoid were involved in bitter melon's anti-diabetic effects as well as on increasing energy expenditure. The triterpenoids composition can however be influenced by changes of varieties or habitats.

OBJECTIVES

To clarify the significance of bioactive metabolites diversity among different bitter melons and to provide a guideline for selection of bitter melon varieties, an exploratory study was carried out using a UHPLC-HRMS based metabolomic study to identify chemotypes.

METHODS

Metabolites of 55 seed samples of bitter melon collected in different parts of China were profiled by UHPLC-HRMS. The profiling data were analysed with multivariate (MVA) statistical methods. Principle component analysis (PCA) and hierarchical cluster analysis (HCA) were applied for sample differentiation. Marker compounds were identified by comparing spectroscopic data with isolated compounds, and additional triterpenes were putatively identified by propagating annotations through a molecular network (MN) generated from UHPLC-HRMS & MS/MS metabolite profiling.

RESULTS

PCA and HCA provided a good discrimination between bitter melon samples from various origins in China. This study revealed for the first time the existence of two chemotypes of bitter melon. Marker compounds of those two chemotypes were identified at different MSI levels. The combined results of MN and MVA demonstrated that the two chemotypes mainly differ in their richness in cucurbitane versus oleanane triterpenoid glycosides (CTGs vs. OTGs).

CONCLUSION

Our finding revealed a clear chemotype distribution of bioactive components across bitter melon varieties. While bioactivities of individual CTGs and OTGs still need to be investigated in more depth, our results could help in future the selection of bitter melon varieties with optimised metabolites profile for an improved management of diabetes with this popular edible Chinese folk medicine.

Identification of triterpene biosynthetic genes from Momordica charantia using RNA-seq analysis

Cucurbitaceae plants contain characteristic triterpenoids. Momordica charantia, known as a bitter melon, contains cucurbitacins and multiflorane type triterpenes, which confer bitter tasting and exhibit pharmacological activities. Their carbon skeletons are biosynthesized from 2,3-oxidosqualene by responsible oxidosqualene cyclase (OSC). In order to identify OSCs in M. charantia, RNA-seq analysis was carried out from ten different tissues. The functional analysis of the resulting four OSC genes revealed that they were cucurbitadienol synthase (McCBS), isomultiflorenol synthase (McIMS), β-amyrin synthase (McBAS) and cycloartenol synthase (McCAS), respectively. Their distinct expression patterns based on RPKM values and quantitative RT-PCR suggested how the characteristic triterpenoids were biosynthesized in each tissue. Although cucurbitacins were finally accumulated in fruits, McCBS showed highest expression in leaves indicating that the early step of cucurbitacins biosynthesis takes place in leaves, but not in fruits.

Abbreviations: OSC: oxidosqualene cyclase; RPKM: reads perkilobase of exon per million mapped reads

Cucurbitane triterpenoids from the fruit of Momordica charantia L. and their anti-hepatic fibrosis and anti-hepatoma activities

Momordica charantia L. (Cucurbitaceae) is a popular vegetable and traditional folk medicine, that has been used for hundreds of years. In this study, three undescribed cucurbitane-type triterpene glycosides furpyronecucurbitane A, goyaglycoside I and charantagenin F along with nine known compounds were isolated from the immature fruit of Momordica charantia L. Their structures were identified on the basis of extensive 1D, 2D NMR and HRESIMS spectroscopy analysis. All isolated compounds were examined for their anti-hepatic fibrosis activity against murine hepatic stellate cells (t-HSC/Cl-6) and anti-hepatoma activity against two kinds of liver cancer cell lines (HepG2 and Hep3B). Among them, karaviloside III exhibited excellent inhibitory activity against activated t-HSC/Cl-6 cells and cytotoxic activity against Hep3B and HepG2 cell lines with IC₅₀ values of 3.74 ± 0.13, 16.68 ± 2.07 and 4.12 ± 0.36 μM, respectively, which may potential to be developed as a chemotherapy agent for treatment hepatic fibrosis or carcinoma and protection against both diseases.

Antiaging of Cucurbitane Glycosides from Fruits of Momordica charantia L

Methanol extracts of Momordica charantia L. fruits are extensively studied for their antiaging activities. A new cucurbitane-type triterpenoid (1) and nine other known compounds (2–10) were isolated, and their structures were determined according to their spectroscopic characteristics and chemical derivatization. Biological evaluation was performed on a K6001 yeast bioassay system. The results indicated that all the compounds extended the replicative lifespan of K6001 yeast significantly. Compound 9 was used to investigate the mechanism involved in the increasing of the lifespan. The results indicated that this compound significantly increases the survival rate of yeast under oxidative stress and decreases ROS level. Further study on gene expression analysis showed that compound 9 could reduce the levels of UTH1 and SKN7 and increase SOD1 and SOD2 gene expression. In addition, it could not extend the lifespan of the yeast mutants of Uth1, Skn7, Sod1, and Sod2. These results demonstrate that compound 9 exerts antiaging effects via antioxidative stress and regulation of UTH1, SKN7, SOD1, and SOD2 yeast gene expression.

Recent Advances in Momordica charantia: Functional Components and Biological Activities

Momordica charantia L. (M. charantia), a member of the Cucurbitaceae family, is widely distributed in tropical and subtropical regions of the world. It has been used in folk medicine for the treatment of diabetes mellitus, and its fruit has been used as a vegetable for thousands of years. Phytochemicals including proteins, polysaccharides, flavonoids, triterpenes, saponins, ascorbic acid and steroids have been found in this plant. Various biological activities of M. charantia have been reported, such as antihyperglycemic, antibacterial, antiviral, antitumor, immunomodulation, antioxidant, antidiabetic, anthelmintic, antimutagenic, antiulcer, antilipolytic, antifertility, hepatoprotective, anticancer and anti-inflammatory activities. However, both in vitro and in vivo studies have also demonstrated that M. charantia may also exert toxic or adverse effects under different conditions. This review addresses the chemical constituents of M. charantia and discusses their pharmacological activities as well as their adverse effects, aimed at providing a comprehensive overview of the phytochemistry and biological activities of M. charantia.

Momordica charantia: a popular health-promoting vegetable with multifunctionality

Products derived from edible medicinal plants have been used for centuries to prevent, treat, and even cure multiple diseases. Momordica charantia L., widely cultivated around the world, is a typical one bred for vegetables and medicinal usage. All parts of M. charantia possess important medicinal properties, including antidiabetic, anticancer, hypotensive, anti-obesity, antimicrobial, antihyperlipidemic, antioxidant, anti-inflammatory, immuno-modulatory, anthelmintic, neuro-protective, as well as hepato-protective properties both in vitro and in vivo. This review summarizes the active components and medicinal properties of M. charantia, especially the activities and mechanisms of its anti-diabetic and anti-cancer properties. The anti-diabetic properties involve inhibiting intestinal α-glucosidase and glucose transport, protecting islet β-cells, enhancing insulin secretion, increasing hepatic glucose disposal, decreasing gluconeogenesis, and even ameliorating insulin resistance. Moreover, the expressions of PPARs could also be activated and up-regulated. Meanwhile, its anticancer properties are mostly due to apoptosis, cell cycle arrest, and expression of serum factors associated with immunity. In this review, we aim to provide an overview of M. charantia and its benefits for development as a functional food.

Cucurbitane-Type Triterpenoids from Momordica charantia

Two new cucurbitane-type triterpenoids, 7β,23( S)-dimethoxycucurbita-5,24-dien-3β-ol (1) and 3 β-hydroxycucurbita-6,23( E),25-trien-5 β,19-olide (2), and two known cucurbitane-type triterpenoids, 7 β,25-dimethoxycucurbita-5,23( E)-dien-3 β-ol (3) and karavilagenin D (4), were isolated from the fruit pulp of Momordica charantia. Their structures were established by means of 1D and 2D NMR spectra (1H, 13C, COSY, HMQC, HMBC, and NOESY) as well as EI-MS data.

A New Cardenolide and Other Compounds from Salsola tetragona

One new cardenolide, 3- O-β-D-allopyranosylcoroglaucigenin (salsotetragonin) (1), was isolated from the aerial parts of Salsola tetragona Delile with four known cardenolides (2–5), two known flavonoids (6–7), three known phenolic compounds (8–10) and two known fatty acids (11–12). Their structures were identified by spectroscopic analyses and by comparison of their spectral data with those reported in the literature. Compounds 1–5, 7, 10 and 12 were isolated from the genus Salsola for the first time. This is the first report on cardenolides identified in the Amaranthaceae family.

Promise of bitter melon (Momordica charantia) bioactives in cancer prevention and therapy

Recently, there is a paradigm shift that the whole food-derived components are not 'idle bystanders' but actively participate in modulating aberrant metabolic and signaling pathways in both healthy and diseased individuals. One such whole food from Cucurbitaceae family is 'bitter melon' (Momordica charantia, also called bitter gourd, balsam apple, etc.), which has gained an enormous attention in recent years as an alternative medicine in developed countries. The increased focus on bitter melon consumption could in part be due to several recent pre-clinical efficacy studies demonstrating bitter melon potential to target obesity/type II diabetes-associated metabolic aberrations as well as its pre-clinical anti-cancer efficacy against various malignancies. The bioassay-guided fractionations have also classified the bitter melon chemical constituents based on their anti-diabetic or cytotoxic effects. Thus, by definition, these bitter melon constituents are at cross roads on the bioactivity parameters; they either have selective efficacy for correcting metabolic aberrations or targeting cancer cells, or have beneficial effects in both conditions. However, given the vast, though dispersed, literature reports on the bioactivity and beneficial attributes of bitter melon constituents, a comprehensive review on the bitter melon components and the overlapping beneficial attributes is lacking; our review attempts to fulfill these unmet needs. Importantly, the recent realization that there are common risk factors associated with obesity/type II diabetes-associated metabolic aberrations and cancer, this timely review focuses on the dual efficacy of bitter melon against the risk factors associated with both diseases that could potentially impact the course of malignancy to advanced stages. Furthermore, this review also addresses a significant gap in our knowledge regarding the bitter melon drug-drug interactions which can be predicted from the available reports on bitter melon effects on metabolism enzymes and drug transporters. This has important implications, given that a large proportion of individuals, taking bitter melon based supplements/phytochemical extracts/food based home-remedies, are also likely to be taking conventional therapeutic drugs at the same time. Accordingly, the comprehensively reviewed information here could be prudently translated to the clinical implications associated with any potential concerns regarding bitter melon consumption by cancer patients.

Bitter melon: a panacea for inflammation and cancer

Nature is a rich source of medicinal plants and their products that are useful for treatment of various diseases and disorders. Momordica charantia, commonly known as bitter melon or bitter gourd, is one of such plants known for its biological activities used in traditional system of medicines. This plant is cultivated in all over the world, including tropical areas of Asia, Amazon, east Africa, and the Caribbean and used as a vegetable as well as folk medicine. All parts of the plant, including the fruit, are commonly consumed and cooked with different vegetables, stir-fried, stuffed or used in small quantities in soups or beans to give a slightly bitter flavor and taste. The plant is reported to possess anti-oxidant, anti-inflammatory, anti-cancer, anti-diabetic, anti-bacterial, anti-obesity, and immunomodulatory activities. The plant extract inhibits cancer cell growth by inducing apoptosis, cell cycle arrest, autophagy and inhibiting cancer stem cells. The plant is rich in bioactive chemical constituents like cucurbitane type triterpenoids, triterpene glycosides, phenolic acids, flavonoids, essential oils, saponins, fatty acids, and proteins. Some of the isolated compounds (Kuguacin J, Karaviloside XI, Kuguaglycoside C, Momordicoside Q-U, Charantin, α-eleostearic acid) and proteins (α-Momorcharin, RNase MC2, MAP30) possess potent biological activity. In the present review, we are summarizing the anti-oxidant, anti-inflammatory, and anti-cancer activities of Momordica charantia along with a short account of important chemical constituents, providing a basis for establishing detail biological activities of the plant and developing novel drug molecules based on the active chemical constituents.

One new 19-nor cucurbitane-type triterpenoid from the stems of Momordica charantia

One new 19-nor cucurbitane-type triterpenoid (3β,9β,25-trihydroxy-7β-methoxy-19-nor-cucurbita-5,23(E)-diene) (1), together with other six known cucurbitane-type triterpenoids (2-7), were isolated from the stems of Momordica charantia L. The chemical structure of 1 was elucidated by extensive 1D NMR and 2D NMR (HSQC, HMBC, COSY and ROESY), MS experiments. Using MTT assay, compound 1 exhibited weak cytotoxicity against HL-60, A-549, and SK-BR-3 cell lines with the IC50 values at 27.3, 32.7 and 26.6 μM, respectively.

Beneficial role of bitter melon supplementation in obesity and related complications in metabolic syndrome

Diabetes, obesity, and metabolic syndrome are becoming epidemic both in developed and developing countries in recent years. Complementary and alternative medicines have been used since ancient era for the treatment of diabetes and cardiovascular diseases. Bitter melon is widely used as vegetables in daily food in Bangladesh and several other countries in Asia. The fruits extract of bitter melon showed strong antioxidant and hypoglycemic activities in experimental condition both in vivo and in vitro. Recent scientific evaluation of this plant extracts also showed potential therapeutic benefit in diabetes and obesity related metabolic dysfunction in experimental animals and clinical studies. These beneficial effects are mediated probably by inducing lipid and fat metabolizing gene expression and increasing the function of AMPK and PPARs, and so forth. This review will thus focus on the recent findings on beneficial effect of Momordica charantia extracts on metabolic syndrome and discuss its potential mechanism of actions.

The effect of Momordica charantia intake on the estrogen receptors ESRα/ESRβ gene levels and apoptosis on uterine tissue in ovariectomy rats

Estrogen or combinational hormone therapy can protect to menopausal symptoms but exogenous estrogen therapy has some potential risks which in turns lead to the appearance of various diseases. In recent years plants with high phytoestrogen content are recommended as therapeutic agents for postmenopausal hormonal treatment. In this research, we investigated the effects of Momordica charantia (MC) on the estrogen production and E2 as well as anti-oxidative and anti-apoptotic role on the ovariectomy rat model. The rats were ovariectomized and fed on 2 g/kg of fruit extra of MC for 30 days by gavage. 17-β estradiol (E2) and 8-OHdG levels in serum, markers of oxidative damage of ROS and ESRα, ESRβ and NF-kB gene levels were measured in uterus horn tissue. Caspase-3, caspase-9, TNF-α, IL-6, IL-10, Bcl-2 and Nf-kB proteins expression were assessed by western blotting. Structural changes in tissue were examined with H&E staining. MC administration also stimulated the E2 production and ESRα/ESRβ gene levels and the inhibited oxidative damage. Furthermore, MC treatment enhanced anti-apoptotic and anti-inflammatory process and tissue regeneration. Data herein support that MC directly regulates uterine estrogen response and may serve as a new phytoestrogenic substance for the treatment of post-menopausal symptoms.

Inhibition of Increases in Blood Glucose and Serum Neutral Fat byMomordica charantiaSaponin Fraction

Focusing on a functional component of Momordica charantia, saponin, we investigated its effects on serum glucose and neutral fat levels. Saponin was extracted as a butanol-soluble fraction (saponin fraction) from hot blast-dried Momordica charantia powder. The disaccharidase-inhibitory activity and the pancreatic lipase-inhibitory activity of the saponin fraction were measured, and in vivo sugar- and lipid-loading tests were performed. The saponin fraction inhibited disaccharidase activity and elevation of the blood glucose level after sucrose loading. The fraction also markedly inhibited pancreatic lipase activity and elevation of the serum neutral fat level after corn oil loading. Based on these findings, the main active component related to the anti-diabetic effect of Momordica charantia is present in the butanol fraction, and it may be saponin. The blood glucose and serum neutral fat-lowering effects of Momordica charantia were closely associated with its inhibitory activity against disaccharidase and pancreatic lipase.

Two new cucurbitane triterpenoids from the seeds of Momordica charantia

Two new cucurbitane triterpenoids 1 and 2 were isolated, together with six known compounds, from the seeds of Momordica charantia L. The structures of new compounds were determined to be 3-O-{[β-d-galactopyranosyl(1 → 6)]-O-β-d-galactopyranosyl}-23(R), 24(R), 25-trihydroxycucur-bit-5-ene (1), 3-O-[β-d-galactopyranosyl]-25-O-β-d-galactopyranosyl-7(R), 22(S), 23(R), 24(R), 25-pentahydroxycucurbit-5-ene (2), respectively. Their structures were elucidated by the combination of mass spectrometry, one- and two-dimensional NMR experiments and chemical reactions.

Two new bidesmoside triterpenoid saponins from the seeds of Momordica charantia L

Two new bidesmoside triterpenoid saponins which were identifed as 28-O-β-d-xylopyranosyl(1→3)-β-d-xylopyranosyl(1→4)-α-l-rhamnopyranosyl(1→2)-[α-l-rhamno-pyranosyl(1→3)]-β-d-fucopyranosyl gypsogenin 3-O-β-d-glucopyranosyl (1→2)-β-d-glucopyranosiduronic acid (C1) and 28-O-β-d-xylopyranosyl(1→4)-α-l-rhamnopyranosyl (1→2)-[α-l-rhamnopyranosyl(1→3)]-β-d-fucopyranosyl gypsogenin 3-O-β-d-gluco-pyranosyl(1→2)-β-d-glucopyranosiduronic acid (C2) were isolated together with two known compounds from the seeds of Momordica charantia L. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments and chemical reactions.

Antiproliferative and hypoglycemic cucurbitane-type glycosides from the fruits of Momordica charantia

This paper reports that bioassay-guided fractionations of EtOH extract of Momordica charantia fruits led to the isolation of 15 cucurbitane-type triterpene glycosides including 4 new compounds, kuguaosides A-D (1-4), along with 11 known ones, charantoside A (5), momordicosides I (6), F1 (7), F2 (8), K (9), L (10), and U (11), goyaglycosides-b (12) and -d (13), 7β,25-dihydroxycucurbita-5,23(E)-dien-19-al 3-O-β-d-allopyranoside (14), and 25-hydroxy-5β,19-epoxycucurbita-6,23-dien-19-on-3β-ol 3-O-β-d-glucopyranoside (15). Their structures were elucidated on the basis of spectroscopic analyses and chemical methods. This study also established the HPLC-ELSD fingerprinting profile of an antiproliferative fraction of which 11 main peaks were identified. Biological evaluation showed that several isolated cucurbitane-type triterpene glycosides had antiproliferative activities against MCF-7, WiDr, HEp-2, and Doay human tumor cell lines. In addition, compound 14 showed potent hypoglycemic activities by glucose uptake assay.

Cucurbitane-Type Triterpenoids from the Fruit Pulp of Momordica Charantia

Three new cucurbitane-type triterpenoids, 5β,19-epoxy-23(R)-methoxycucurbita-6,24-dien-3β-ol (1), 5β,19-epoxy-23(S)-methoxycucurbita-6,24-dien-3β-ol (2), and 3β-hydroxy-23(R)-methoxycucurbita-6,24-dien-5β,19-olide (3), were isolated from the fruit pulp of Momordica charantia. Their structures were established on the basis of extensive NMR (1H, 13C, COSY, HMQC, HMBC, and NOESY) and EI-MS studies. Compound 1 exhibited cytotoxic activity against the SK-Hep 1 cell line.

Cucurbitane triterpenoids from the leaves of Momordica charantia, and their cancer chemopreventive effects and cytotoxicities

Seventeen cucurbitane-type triterpenoids, 1-17, including six new compounds, (23E)-3β,25-dihydroxy-7β-methoxycucurbita-5,23-dien-19-al (1), (23S*)-3β-hydroxy-7β,23-dimethoxycucurbita-5,24-dien-19-al (6), (23R*)-23-O-methylmomordicine IV (7), (25ξ)-26-hydroxymomordicoside L (8), 25-oxo-27-normomordicoside L (9), and 25-O-methylkaravilagenin D (12), were isolated from a MeOH extract of the leaves of Japanese Momordica charantia. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses and comparison with literature. Compounds 1-17 were examined for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, a known primary screening test for inhibitors of tumor promotion. Four compounds, 1, (23E)-3β,7β-dihydroxy-25-methoxycucurbita-5,23-dien-19-al (2), karavilagenin D (11), and 12, showed potent inhibitory effects on EBV-EA induction with IC(50) values in the range of 242-264 mol ratio/32 pmol TPA. In addition, compounds 1 and 11 exhibited inhibitory effects on skin-tumor promotion in an in vivo two-stage mouse skin carcinogenesis test based on 7,12-dimethylbenz[a]anthracene (DMBA) as initiator, and with TPA as a promoter. Furthermore, upon evaluation of the cytotoxic activities of compounds 1-17 against human cancer cell lines, compounds 2, 5-7, 9, and 14 showed potent activities against HL60 cell line, and compound 2 against SK-BR-3 cell line.

Structures of new triterpenoids and cytotoxicity activities of the isolated major compounds from the fruit of Momordica charantia L

Two new cucurbitane-type triterpene glycosides, charantagenins D (1) and E (2), and one new sterol, 7-oxo-stigmasta-5,25-diene-3-O-β-d-glucopyranoside (3), were isolated from the fruit of Momordica charantia L. together with another eight known compounds. Their structures were determined on the basis of spectral analysis. Cytotoxicity activities of the isolated major compounds were evaluated against lung cancer cell line A549, glioblastoma cell line U87, and hepatoma carcinoma cell line Hep3B by using a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) in vitro assay. Results showed compounds 1 and 7 (goyaglycoside d) with an -OMe substituent group in the side chain exhibited significant cytotoxic activities against cancer cells. Impressively, the IC(50) values of the new compound 1 to A549, U87, and Hep3B were 1.07, 1.08, and 14.01 μmol/L, respectively, which were much lower than those of other tested compounds.