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Ethnopharmacological Relevance: As obesity is a key factor in the development of type 2 diabetes, lowering lipid accumulation in adipose tissues is as important as increasing insulin sensitivity in diabetic patients. The selected plant extracts used in this screen have been traditionally used in Indonesian medicine for the treatment of diabetes and its complications., Aim of the Study: To investigate the ability of the selected plants to both increase insulin sensitivity through the enhancement of glucose uptake after insulin induction in adipocytes and suppress lipid production in the same target cells., Materials and Methods: Dried Indonesian medicinal plants were extracted with 50% (v/v) aq. methanol. The extracts were dissolved in 50% DMSO when tested in 3T3-L1 adipocytes. The screening platform consists of insulin-induced glucose uptake, lipid accumulation, and cell viability. Initially, an enzymatic fluorescence assay was designed to demonstrate the enhancement of 2-deoxyglucose (2-DG) uptake after insulin induction. Different concentrations of the extracts that enhanced glucose uptake were subjected to lipid accumulation assay using Oil Red O staining. Potential extracts based on lipid suppression were subsequently assessed by CCK-8 cell viability assay to distinguish lipid reduction activity from cytotoxicity., Results: Out of 59 plants, 13 plants demonstrated their ability to increase glucose uptake in 3T3-L1 adipocytes after insulin induction, and 4 of these plants' extracts suppressed lipid production of the cells. The CCK-8 assay results of those 4 plant extracts suggest that the lipid inhibition activity of Eurycoma longifolia Jack (root) and Piper nigrum L. (fruits) extracts is not attributed to their cytotoxicity in the adipose cells. Both of the plant extracts increased glucose uptake by more than 200% at 50 μg/mL and suppressed lipid accumulation in a concentration-dependent manner., Conclusions: Screening of selected Indonesian medicinal plants has uncovered the potentials of E. longifolia Jack (root) and P. nigrum L. (fruits) with dual active functions, increasing insulin sensitivity through the enhancement of glucose uptake and reducing lipid accumulation in adipose cells. These findings suggest that the ability of both plants to suppress lipid production would provide additional benefits in the treatment of diabetes., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

A promising approach for treating diabetes mellitus (DM) is to decrease postprandial hyperglycaemia by suppressing carbohydrate digestion using α-glucosidase inhibitors. Pluchea indica leaf extracts possess inhibitory activity against intestinal maltase. Enzyme assay-guided fractionation by chromatography yielded five active caffeoylquinic acid derivatives (1-5). Their structures were elucidated by mass spectrometry and NMR analysis and completed by comparison with reference data. 3,5-Di-O-caffeoylquinic acid (1), 4,5-di-O-caffeoylquinic acid methyl ester (2), 3,4,5-tri-O-caffeoylquinic acid methyl ester (3), 3,4,5-tri-O-caffeoylquinic acid (4) and 1,3,4,5-tetra-O-caffeoylquinic acid (5) were isolated. Comparison of the activities of each isolate suggested that both methyl esterification of quinic acid and the number of caffeate groups in the molecule were important for the inhibitory activity. This study provides basic information for further examination of the suitability of P. indica as a functional food and medicinal supplement for the treatment and prevention of diabetes.

Inhibition of pancreatic lipase is effective for a prevention of obesity. Eugenia polyantha is a tropical tree whose leaves are known as a spice and also as an ingredient for Jamu, the traditional medicine of Indonesia. We found inhibitory activity against pancreatic lipase in the extract of E. polyantha leaves. Purification of the active principals resulted in isolation of hydroxychavicol, and two structurally new dimers. All of the isolated compounds showed inhibitory activity against the porcine pancreatic lipase and high content of hydroxychavicol (1.83 wt.%) indicated this compound to be responsible for the majority of inhibitory activity of E. polyantha extract. Furthermore, hydroxychavicol is reported to possess anti-carcinogenic, anti-oxidant, anti-microbial and anti-inflammatory activity which is related to traditional usage of this plant. These results offer this plant as an attractive material for treating various health problems including obesity., (Copyright © 2012 Elsevier Ltd. All rights reserved.)