The antihyperglycaemic and antiobesity effects of selected compounds from garcinia malaccensis on 3t3-l1 adipocytes

The increase incidence in diabetes-and obesity-related diseases in developed and developing countries has driven serious efforts towards the discovery of adipogenic differentiation-inhibitory compounds in natural products. Mangostins and triterpenoids from Garcinia have been reported to contain a wide range of bioactivities. However, its antidiabetic and antiobesity activity has not been previously addressed. With regard to the fact, this research is designed to study the antihperglycaemic and antiobesity effects of selected phytochemicals isolated from Garcinia malaccensis namely beta-mangostin and cycloartane triterpenoid. The compounds were tested for their antihyperglycaemic and antiobesity effects in 3T3-L1 adipocytes. In this study, we first elucidated the effects the compounds on the lipid accumulation of 3T3-L1 preadipocytes by using Oil Red O staining. The ability of the cell to uptake glucose was measured by liquid scintillation counter. Peroxisome proliferator-activated receptors gamma (PPARy), glucose transporter four (GLUT4) and leptin genes expression was determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The results showed that β-mangostin reduced the triglyceride accumulation in 3T3-L1 adipocytes with highest lipid inhibition activity was observed at 50 μM concentration (p<0.05) when compared to MDI (0.5 mM 3-isobutyl-1-methyl-xanthine (IBMX), 0.25 mM dexamethasone, 1 μg/mL insulin) treated cells. On the other hand, treatment with cycloartane triterpenoid significantly induced lipid accumulation. Analyses of 2-deoxy-D-[3H] glucose uptake activities showed that all the compounds including the MDI, metformin and sodium orthovanadate (positive control) significantly (p<0.05) improved the glucose uptake when compared to the basal cell. In addition, evaluation by using the adipolysis kit (Cayman Chemicals) showed that β-mangostin increases the amount of free fatty acid (FFA) release. Further evaluation by the gene expression analysis showed that β-mangostin may reduce lipid accumulation by inhibition of the expression of PPARγ genes. In addition, induction of glucose uptake and free fatty acid release by β-mangostin was accompanied by increasing of mRNA expression of GLUT4 and leptin. Interestingly, mature 3T3-L1 cells treated with cycloartane triterpenoid was shown to enhance PPARγ and GLUT4 gene expression and decreased leptin expression. As a conclusion, these line of evidences indicated that β-mangostin and cycloartane triterpenoid derived from Garcinia malaccensis may become an interesting candidate for the prevention of metabolic disorders such as diabetes and obesity

In vitro activities of Malaysian antidiabetic plant extracts on adipocytes cell

Diabetes mellitus is widely known as a metabolic disorder and it is becoming a major public health concern in most developing countries. The majority of type 2 patients are sufficiently insulin-resistant, which is defined as defective insulin signaling and a decreased insulin efficiency to induce glucose transport from the blood into key target cells such as muscle and fat cells (adipocyte) (Khan et aI., 2003). For these patients, more insulin is not necessarily the ideal treatment strategy. A multitude of herbs, spices, and other plant materials have been described for the treatment of diabetes mellitus around the world. To date, the demand for natural products is high and thus, this has increased attention to alternative medicine

Mangostins stimulate glucose uptake and inhibit adipocyte differentiation in 3T3-L1 adipocytes

Garcinia mangostana (Guttiferae) has interesting biological activities with potential medicinal application. α-mangostin and β-mangostin are the most abundant xanthones isolated from the species. The paper reported the inhibitory effect of the compounds on triglyceride formation, glucose uptake stimulation and gene expression effects on 3T3-L1 adipocytes. Evaluation of the effect of the compounds on triglyceride accumulation was examined by Oil red O staining. The result showed that all compounds inhibited lipid accumulation on 3T3-L1 adipocytes at concentration of 50 μM (P < 0.05) compared to MDI treated cells in a dose-dependent manner. Effect of the cells on uptake of 2-deoxy-D-[3H]glucose was significantly improved by increasing the concentration of the compounds. Analysis of gene expressions by quantitative real-time PCR demonstrated that the compounds inhibited the expression of early adipogenic transcription factor (PPARγ). In addition, the compounds enhanced the expression and plasma membrane translocation of GLUT4 in mature adipocytes. Analysis by using the adipolysis kit showed that α-mangostin particularly increases the free fatty acid release by stimulating the lipolysis pathway. Therefore, these results suggested that α-mangostin and β-mangostin have been found to have a beneficial action in diabetic complications (antiobesity effect) via stimulation of GLUT4 expression and inhibition of PPARγ expression

Xanthones from Garcinia Malaccencis improve Glut4 aswell as decreased Pparγ activation on adipocytes

In this study, we used α-mangostin, the major xanthone compounds and β-mangostin from Garcinia malaccensis Hk.f (locally known as “manggis burung”) and evaluate its in vitro activities on adipocyte differentiation, glucose uptake and related gene expression (pparγ and glut4) mechanism. Firstly, we elucidated the inhibitory effect of the compounds on lipid accumulation of 3T3-L1 preadipocytes by using Oil red O staining. Cell treated with α-mangostin and β-mangostin dose-dependently was found to inhibit the cytoplasmic lipid accumulation as well as adipogenic differentiation of preadipocyte. All compounds showed high lipid inhibition activity at 50 μg/mL concentration (P < 0.05) compared to MDI treated cells. Besides, glucose uptake activity was investigated in differentiated adipocytes using a radioactive-labelled glucose by Liquid Scintillation Counter. The insulin-induced 2-deoxy-D-[3H] glucose uptake activities were significantly improved with increasing the concentration of the test compounds. Further evaluation with the quantitative real time polymerase chain reaction (qRT-PCR) shows that α-mangostin and β-mangostin reduced the expression of pparγ genes during adipocyte differentiation. At the same time, induction of glucose uptake by α-mangostin and β-mangostin was accompanied by the increased mRNA expression of glut4 genes. Since downregulation of pparγ has been reported to be activated during inhibition of adipogenesis and enhance expression of glut4 has been shown to be increased during glucose uptake we demonstrated that both compounds follow the antiobesity pathways. Taken together, these results indicate that xanthones derived from Garcinia malaccencis may be a candidate for preventing metabolic disorders such as obesity

Insulin mimicking activities of Cycloartane Triterpenoid in 3T3-L1 cells

Type 2 diabetes is a metabolic disorder characterized by insulin resistance, insulin action and caused by multifactorial etiology, including environmental factors, particularly diet and genetic components. Recently, most research on diabetes has focus on adipocyte which is used as a model for testing of insulin sensitivity and novel antidiabetic drugs. In this study, we investigated the effects of cycloartane triterpenoid on the adipocyte differentiation and glucose uptake in 3T3-L1 cells together with its underlying gene expression. The cells were treated for triglyceride accumulation with different concentration of the compound using Oil Red O staining assay. After 8-days, morphological changes and increase lipid accumulation were observed in these cells (p<0.05). Indeed, the intracellular lipid accumulation increased by 1.9 fold relative to MDI-treated control cells at concentration of 50 µM. Analysis of insulin-induced 2-deoxy-D-[3H] glucose uptake activities shows that cycloartane triterpenoids significantly (p<0.01) improved the glucose uptake with increasing the concentration of the compounds as compared to the basal. Further evaluation with the quantitative real time polymerase chain reaction (qRT-PCR) shows that mature 3T3-L1 cells treated with cycloart-24-en-3β-ol enhance pparγ and glut4 gene expression. As a result, it demonstrated that cycloartane triterpenoids enhance pparγ and glut4 gene expression. Taken together, these results suggest that cycloart-24-en-3β-ol derived from Garcinia malaccencis could improve insulin sensitivity through the activation of pparγ as a ligand and glut4

α-mangostin improves glucose uptake and inhibits adipocytes differentiation in 3T3-L1 cells via PPARgamma, GLUT4, and leptin expressions

Obesity has been often associated with the occurrence of cardiovascular diseases, type 2 diabetes, and cancer. The development of obesity is also accompanied by significant differentiation of preadipocytes into adipocytes. In this study, we investigated the activity of α-mangostin, a major xanthone component isolated from the stem bark of G. malaccensis, on glucose uptake and adipocyte differentiation of 3T3-L1 cells focusing on PPARγ, GLUT4, and leptin expressions. α-Mangostin was found to inhibit cytoplasmic lipid accumulation and adipogenic differentiation. Cells treated with 50 μM of α-mangostin reduced intracellular fat accumulation dose-dependently up to 44.4% relative to MDI-treated cells. Analyses of 2-deoxy-D-[3H] glucose uptake activity showed that α-mangostin significantly improved the glucose uptake ( P < 0.05 ) with highest activity found at 25 μM. In addition, α-mangostin increased the amount of free fatty acids (FFA) released. The highest glycerol release level was observed at 50 μM of α-mangostin. qRT-PCR analysis showed reduced lipid accumulation via inhibition of PPARγ gene expression. Induction of glucose uptake and free fatty acid release by α-mangostin were accompanied by increasing mRNA expression of GLUT4 and leptin. These evidences propose that α-mangostin might be possible candidate for the effective management of obesity in future

Friedelin and lanosterol from Garcinia prainiana stimulated glucose uptake and adipocytes differentiation in 3T3-L1 adipocytes

Friedelin and lanosterol have been isolated from twigs of Garcinia prainiana.Their structures were elucidated by spectroscopic methods. The compounds were examined for their effects on 3T3-L1 adipocytes. In the MTT assay, it was found that the compounds had no cytotoxic effects up to 25 mM. Adipocyte differentiation analysis was carried out by Oil Red O staining method. In the presence of adipogenic cocktail (MDI), it was found that friedelin and lanosterol enhanced intracellular fat accumulation by 2.02 and 2.18-fold, respectively, compared with the vehicle-treated cells. Deoxyglucose uptake assay was used to examine the insulin sensitivity of adipocytes in the presence of the compounds. It was found that friedelin was able to stimulate glucose uptake up to 1.8-fold compared with insulin-treated cells. It was suggested that friedelin and lanosterol may be beneficial to mimic insulin action that would be useful in the treatment of diabetes type 2 patients

Antidiabetic activities of Cinnamomum zeylanicum and Tinospora crispa on adipocytes

The effects of Cinnamomum burmannii and Tinospora crispa on differentiation and glucose uptake in 3T3-L1 adipocyte cells were studied. Cells were stimulated to differentiate with differentiation cocktail containing Dulbecco’s modified Eagle’s medium (DMEM) with 10% fetal bovine serum (FBS), 0.25 µM dexamethasone, 0.5 mM 3-isobutyl-1-methyl-xanthine and 167 µM insulin. 3T3-L1 preadipocytes were treated with various concentrations of the extracts in the presence of differentiation cocktail. Insulin was used as a positive control. The ability of the extracts to induce differentiation in preadipocytes was examined by measuring fat accumulation using oil red O staining. Our results showed that C. burmannii and T. crispa was statistically significant in inducing preadipocyte into mature adipocyte at dose of 0.1 mg/mL (p < 0.001) and 0.5 mg/mL (p < 0.05), respectively. Glucose uptake activity was investigated in differentiated adipocytes using a radioactive-labelled glucose by Liquid Scintillation Counter. The activities in the glucose uptake between untreated and treated cells showed that both plants were statistically significant compared metformin (1 mM), but not significant compared to sodium orthovanadate (5 mM). In conclusion, these results suggest that both plants were effective in inducing adipocyte differentiation and stimulate glucose uptake

Direct and indirect antimicrobial effects of α-mangostin on pathogenic microorganisms

Objective: To test direct and indirect antimicrobial properties of α-mangostin towards a number of bacteria and fungi. Methods: The experiment was carried out using broth microdilution and checkerboards methods. Activity of α-mangostin paired with an antibiotic was studied by calculating its fractional inhibitory concentration (FIC). Results: The activity of all four bacteria towards ampicillin, penicillin G, streptomycin and tetracycline showed no interaction with the combination with α-mangostin where the FIC indexes were between the range of 0.54. Activity of doxycycline on Pseudomonas aeruginosa fell into other set of range, FICindex≥4 which is an antagonism. Conclusions: The FIC index is far away in the range. The coupled antibiotic and α-mangostin is considered synergy in action if it lies in FICindex≤0.5 and it was found that the isolated compound, α-mangostin revealed very low synergistic antimicrobial effects when coupled with antibiotics