Peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-activated transcription factor that regulates lipid and glucose metabolism. We investigated the effects of Labisia pumila (LP) standardized water extract on PPARgamma transcriptional activity in adipocytes in vitro and in vivo. We used a rat model of dihydrotestosterone- (DHT-) induced polycystic ovary syndrome (PCOS), a condition characterized by insulin resistance. At 9 weeks of age, the PCOS rats were randomly subdivided into two groups: PCOS-LP (50？mg/kg/day of LP) and PCOS-control (1？mL of deionised water) for 4-5 weeks on the same schedule. Real-time RT-PCR was performed to determine the PPARgamma mRNA levels. LP upregulated PPARgamma mRNA level by 40% in the PCOS rats. Western blot analysis further demonstrated the increased PPARgamma protein levels in parallel with upregulation in mRNA. These observations were further proven by adipocytes culture. Differentiated 3T3-L1 adipocytes were treated with final concentration of 100？μg/mL LP and compared to untreated control and 10？μM of rosiglitazone (in type of thiazolidinediones). LP increased PPARgamma expressions at both mRNA and protein levels and enhanced the effect of glucose uptake in the insulin-resistant cells. The data suggest that LP may ameliorate insulin resistance in adipocytes via the upregulation of PPARgamma pathway. 1. Introduction Labisia pumila var. alata (LP) (family, Myrsinaceae) or its local name, Kacip Fatimah, is a herbal plant with long history of being used as traditional medicine by Asian women especially those from the Malay Archipelago [1]. The plant grows in lowland primary forest at shady places or in secondary forests on humus-rich soils [2]. The water decoction is traditionally consumed to maintain women’s pre- and postpartum health [1, 3]. Components identified in LP extracts include flavonoids, ascorbicacid, beta-carotene, anthocyanin, phenols, and total saponins [4, 5]. Insulin resistance is characterized by a decrease in the uptake of glucose, especially by insulin target tissues, including adipose tissue and skeletal muscle [6]. Instead of merely being a storage depot, adipose tissue is now recognized as an important regulator of energy homeostasis [7] and a central player in the development of insulin resistance [8, 9]. One key factor in supporting the central role of adipose tissue in whole-body glucose metabolism is peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear receptor that is critical both for adipocyte differentiation and for maintenance of mature adipocytes.
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