Antioxidant and Anti-diabetic Properties of Bitter Gourd (Momordica charantia) Fruit

This study aimed to determine the therapeutic values of local bitter gourd relative to the conventional drugs, especially in managing oxidative stress and blood glucose. The therapeutic values of bitter gourd fruit were evaluated using three antioxidant assays (2,2-diphenyl-1-picrylhydrazyl scavenging system [DPPH], the ability of ferric ion reduction in plasma [FRAP], total phenolic content [TPC]) and three hyperglycemic assays (inhibition of α-amylase and α-glucosidase and glucose uptake by human carcinoma liver cell [HepG2]). The result showed that bitter gourd fruit is not only a powerful secondary antioxidant but also a potent anti-diabetic food, which supported the use of bitter gourd fruit in suppressing high blood sugar in traditional medicine

Bioaccessibility of apigenin from Mangifera indica (Water Lily var.) during in vitro gastrointestinal digestion

The bioaccessibility property of apigenin from Mangifera indica (Water Lily var.) was investigated using in vitro gastrointestinal digestion model. Two digestion stages were simulated namely the gastric and small intestinal digestion by using different enzymes and physiological conditions that mimicked the digestion process. Following digestion, the bioaccessible apigenin was analysed using HPLD-DAD-MS. Results showed that the apigenin fraction in intestinal phase was higher than in gastric phase with amounts 1.03 ± 0.35 mg/100 g DW and 0.50 ± 0.08 mg/100 g DW, respectively. After 1 h exposure to gastric juice, the bioaccessibility of apigenin was 20.26 ± 3.06% with 79.74 ± 3.06% losses during the digestion, whereas in intestinal phase, the percentage of bioaccessibility significantly increased to 41.53 ± 13.99% and 58.47 ± 13.99% losses after 2 h treatment with pancreatin. It was concluded that the apigenin in Water Lily mango became bioaccessible, suggesting the absorption possibility of the compound in the upper part of intestine, which can lead to the health-related outcomes

Intestinal permeability and transport of apigenin across caco-2 cell monolayers

Investigation on bioavailability was carried out by determining the absorption and transport of bioaccessible apigenin from Mangifera indica (Water Lily var.) into Caco-2 human intestinal cell using a reliable and sensitive analytical method of LC-MS/MS. Results revealed that the concentration of glucuronidated apigenin lower than apigenin. The apigenin was metabolised inside the cells through glucuronidation process, and cross the monolayer to reach the basolateral sides or effluxed back to the apical side. The permeability coefficient of apigenin from apical to basolateral sides and basolateral to apical sides showed a medium permeability was less than 20 x10-6 cm.sec-1. Since the value of efflux ratio was 1.5, it suggested that the apigenin was absorbed and transported through a simple diffusion mechanism

Antioxidant and hypoglycaemic effects of local bitter gourd fruit (Momordica charantia)

Antioxidant and anti-diabetic properties of two local bitter gourd species namely peria kambas and peria katak were screened with 3 antioxidant assays (2,2-diphenyl-1-picrylhydrazyl [DPPH], the ability of ferricion reduction in plasma [FRAP] and total phenolic content [TPC]) and 2 inhibition assays of key enzymes in carbohydrate metabolism (α-amylase and α-glucosidase). Mature peria katak appeared as stronger antioxidant vegetables in three antioxidant assays (51.1 % in DPPH inhibition, 0.63 g gallic acid equivalent and 2.29 g Trolox equivalent/100 g dried weight of peria katak) than peria kambas. Besides, it also reported to be 21% and almost three fold stronger in inhibiting the activity of enzymes α-amylase and α-glucosidase as compared to another bitter gourd cultivar. These pharmacology properties of peria katak were further determined along the ripening stages. Again, it was found that mature peria katak showed the highest antioxidant potential as well as the highest half maximal inhibitory concentration (IC50) values of 0.63 mg/mL and 0.62 mg/mL for α-amylase and α-glucosidase enzyme inhibition assays respectively. Interestingly, mature peria katak was more effective than acarbose, one of the commonly used oral anti diabetic drug in inhibiting α -amylase activity and almost as good as acarbose in inhibiting α-glucosidase activity. In conclusion, peria katak is more effective than peria kambas in suppressing free radical and decreasing hyperglycemia post-ingestion. Therefore, the local mature peria katak can serve as a better antioxidant and anti-diabetic tool in food and nutraceutical product development

New diprenylated dihyrochalcones from leaves of Artocarpus elasticus

Two new diprenylated dihydrochalcones, elastichalcone A 1 and elastichalcone B 2 and three known compounds were isolated from the leaves of Artocarpus elasticus. Their structures were determined by various spectroscopic techniques (UV, IR, MS, 1D-NMR and 2D-NMR). Elastichalcone B 2 and a known compound exhibited good free radical scavenging activity with IC50 values of 11.30 and 11.89 μg/ml, respectively. © 2013 Phytochemical Society of Europe

Xanthorrhizol inhibits cell proliferation, cellular cholesterol uptake in HT29 colon cells and adipogenesis in 3T3-L1 adipocytes

Hyperlipidemia is defined as the presence of either hypertriglyceridemia or hypercholesterolemia, which could cause atherosclerosis, cardiovascular diseases and certain cancers. Although hyperlipidemia can be treated by hypolipidemic drugs, they are limited due to lack of effectiveness and safety. Since flavonoids and tannins have been reported to possess antihyperlipidemic activity, it is believed that phytochemicals isolated from plants may decrease the lipid levels with lower side effects. Previous studies demonstrated that xanthorrhizol (XNT) isolated from Curcuma xanthorrhizza reduced the levels of free fatty acid and triglyceride in vivo. However, antiproliferative activity of XNT and its ability to inhibit cholesterol uptake and adipogenesis are yet to be reported. In this study, the IC50 values of XNT were 15.12 ± 0.68 μg/mL in HT29 cells and 35.07 ± 0.24 μg/mL in 3T3-L1 adipocytes, respectively. Cholesterol uptake inhibition study was conducted in HT29 colon cells using fluorescent cholesterol analogue NBD. The result showed that XNT (15 μg/mL) siginificantly inhibited the cholesterol uptake by up to 37.6 ± 1.53 % relative to control. On the other hand, higher concentration of XNT (50 μg/mL) significantly suppressed the growth of 3T3-L1 adipocytes (5.9 ± 0.58 %) compared to 3T3-L1 preadipocytes (80.42 ± 8.29 %). It was found that XNT (3.125 μg/mL) impeded adipogenesis by reducing lipid content of 3T3-L1 adipocytes for 25.37 ± 3.24 % comparable to positive control (quercetin), 20.07 ± 8.78%. We postulate that inhibition of cholesterol uptake, adipocyte number and adipogenesis may be utilized as treatment modalities to reduce the prevalence of lipidemia. To conclude, XNT could be a potential hypolipidemic agent and further studies could be done on its mechanism of action

Hypolipidemic activities of xanthorrhizol purified from centrifugal TLC

Hyperlipidemia is defined as the presence of either hypertriglyceridemia or hypercholesterolemia, which could cause atherosclerosis. Although hyperlipidemia can be treated by hypolipidemic drugs, they are limited due to lack of effectiveness and safety. Previous studies demonstrated that xanthorrhizol (XNT) isolated from Curcuma xanthorrhizza Roxb. reduced the levels of free fatty acid and triglyceride in vivo. However, its ability to inhibit cholesterol uptake in HT29 colon cells and adipogenesis in 3T3-L1 cells are yet to be reported. In this study, XNT purified from centrifugal TLC demonstrated 98.3% purity, indicating it could be an alternative purification method. The IC50 values of XNT were 30.81 ± 0.78 μg/mL in HT29 cells and 35.07 ± 0.24 μg/mL in 3T3-L1 adipocytes, respectively. Cholesterol uptake inhibition study using HT29 colon cells showed that XNT (15 μg/mL) significantly inhibited the fluorescent cholesterol analogue NBD uptake by up to 27 ± 3.1% relative to control. On the other hand, higher concentration of XNT (50 μg/mL) significantly suppressed the growth of 3T3-L1 adipocytes (5.9 ± 0.58%) compared to 3T3-L1 preadipocytes (81.31 ± 0.55%). XNT was found to impede adipogenesis of 3T3-L1 adipocytes in a dose-dependent manner from 3.125 to 12.5 μg/mL, where 12.5 μg/mL significantly suppressed 36.13 ± 2.1% of lipid accumulation. We postulate that inhibition of cholesterol uptake, adipogenesis, preadipocyte and adipocyte number may be utilized as treatment modalities to reduce the prevalence of lipidemia. To conclude, XNT could be a potential hypolipidemic agent to improve cardiovascular health in the future

Clausenidin from Clausena excavata induces apoptosis in hepG2 cells via the mitochondrial pathway

Ethnopharmacological relevance: Clausena excavata Burm.f. is used locally in folk medicine for the treatment of cancer in South East Asia. Aim of the study: To determine the mechanism of action of pure clausenidin crystals in the induction of hepatocellular carcinoma (hepG2) cells apoptosis. Materials and methods: Pure clausenidin was isolated from Clausena excavata Burm.f. and characterized using 1H and 13C NMR spectra. Clausenidin-induced cytotoxicity was determined by MTT assay. The morphology of hepG2 after treatment with clausenidin was determined by fluorescence and Scanning Electron Microscopy. The effect of clausenidin on the apoptotic genes and proteins were determined by real-time qPCR and protein array profiling, respectively. The involvement of the mitochondria in clausenidin-induced apoptosis was investigated using MMP, caspase 3 and 9 assays. Results: Clausenidin induced significant (p<0.05) and dose-dependent apoptosis of hepG2 cells. Cell cycle assay showed that clausenidin induced a G2/M phase arrest, caused mitochondrial membrane depolarization and significantly (p<0.05) increased expression of caspases 3 and 9, which suggest the involvement of the mitochondria in the apoptotic signals. In addition, clausenidin caused decreased expression of the anti-apoptotic protein, Bcl 2 and increased expression of the pro-apoptotic protein, Bax. This finding was confirmed by the downregulation of Bcl-2 gene and upregulation of the Bax gene in the treated hepG2 cells. Conclusion: Clausenidin extracted from Clausena excavata Burm.f. is an anti-hepG2 cell compound as shown by its ability to induce apoptosis through the mitochondrial pathway of apoptosis. Clausenidin can potentially be developed into an anticancer compound

Comparative study of the antidiabetic potential of Paederia foetida twig extracts and compounds from two different locations in Malaysia

Context: Paederia foetida L. (Rubiaceae) is an edible plant distributed in Asian countries including Malaysia. Fresh leaves have been traditionally used as a remedy for indigestion and diarrhea. Several phytochemical studies of the leaves have been documented, but there are few reports on twigs. Objective: This study investigates the enzyme inhibition of P. foetida twig extracts and compound isolated from them. In addition, in silico molecular docking of scopoletin was investigated. Materials and methods: Plants were obtained from two locations in Malaysia, Johor (PFJ) and Pahang (PFP). Hexane, chloroform and methanol extracts along with isolated compound (scopoletin) were evaluated for their enzyme inhibition activities (10,000-0.000016 µg/mL). The separation and identification of bio-active compounds were carried out using column chromatography and spectroscopic techniques, respectively. In silico molecular docking of scopoletin with receptors (α-amylase and α-glucosidase) was carried out using AutoDock 4.2. Results: The IC50 values of α-amylase and α-glucosidase inhibition activity of PFJ chloroform extract were 9.60 and 245.6 µg/mL, respectively. PFP chloroform extract exhibited α-amylase and α-glucosidase inhibition activity (IC50 = 14.83 and 257.2 µg/mL, respectively). The α-amylase and α-glucosidase inhibitory activity of scopoletin from both locations had IC50 values of 0.052 and 0.057 µM, respectively. Discussion and conclusions: Separation of PFJ chloroform extract afforded scopoletin (1), stigmasterol (2) and γ-sitosterol (3) and the PFP chloroform extract yielded (1), (2), (3) and ergost-5-en-3-ol (4). Scopoletin was isolated from this species for the first time. In silico calculations gave a binding energy between scopoletin and α-amylase of -6.03 kcal/mol

Xanthorrhizol: a review of its pharmacological activities and anticancer properties

Xanthorrhizol (XNT) is a bisabolane-type sesquiterpenoid compound extracted from Curcuma xanthorrhiza Roxb. It has been well established to possess a variety of biological activities such as anticancer, antimicrobial, anti-inflammatory, antioxidant, antihyperglycemic, antihypertensive, antiplatelet, nephroprotective, hepatoprotective, estrogenic and anti-estrogenic effects. Since many synthetic drugs possess toxic side effects and are unable to support the increasing prevalence of disease, there is significant interest in developing natural product as new therapeutics. XNT is a very potent natural bioactive compound that could fulfil the current need for new drug discovery. Despite its importance, a comprehensive review of XNT’s pharmacological activities has not been published in the scientific literature to date. Here, the present review aims to summarize the available information in this area, focus on its anticancer properties and indicate the current status of the research. This helps to facilitate the understanding of XNT’s pharmacological role in drug discovery, thus suggesting areas where further research is required