PPAR gamma

ETHNOPHARMACOLOGICAL RELEVANCE: The fruits of Terminalia bellerica Roxb. (Combretaceae) and T. chebula Retz. (Combretaceae) are important components of triphala, a popular Ayurvedic formulation, for treating diabetes in Indian traditional medicine. AIM OF THE STUDY: The aim of this study was to evaluate the effects of the constituents of T. bellerica and T. chebula fruit extracts on PPAR? and PPAR? signaling/expression, cellular glucose uptake and adipogenesis. MATERIALS AND METHODS: PPAR? and PPAR?

Medicinal plants are a rich source of ligands for nuclear receptors. The present study was aimed to screen a collection of plant extracts for PPAR?/?-activating properties and identify the active extract that can stimulate cellular glucose uptake without enhancing the adipogenesis. A reporter gene assay was performed to screen ethanolic extracts of 263 plant species, belonging to 94 families, for activation of PPAR? and PPAR?. Eight extracts showed activation of PPAR?, while 22 extracts showed activation of PPAR?.

The thiazolidinedione (TZDs) class of drugs are very effective for the treatment of type 2 diabetes mellitus (T2DM). But due to the adverse effects of synthetic TZDs, their use is strictly regulated. The therapeutic actions of TZDs are mediated via modulation of peroxisome proliferator-activated receptor gamma (PPAR?). Naturally occurring PPAR? modulators are more desirable as they lack the serious adverse effects caused by TZDs. This has prompted the exploitation of medicinal plants used in traditional medicine, for their potential PPAR? activity.

The nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARgamma) helps to translate 'what you eat' into 'what you are' because it allows dietary fatty acids (PPARgamma ligands) to modulate gene transcription. Treatments for diabetes include PPARgamma activators, as they sensitize the body to insulin. Our understanding of PPARgamma function has recently been enhanced by a flurry of human and mouse genetic studies, and the characterization of new PPARgamma ligands.

White adipose tissue now emerges as a pivotal organ controlling lifespan. Calorie restriction, which so far extends lifespan in all organisms, primarily affects energy stores in adipose tissue. Genetic manipulations aiming at modifying fat mass also impact on the duration of life in several model organisms. We recently proposed that silent information regulator 2 (SIR2) ortholog, sirtuin 1 (SIRT1), the mammalian ortholog of the life-extending yeast gene SIR2, is involved in the molecular mechanisms linking lifespan to adipose tissue.

Calorie restriction (CR) promotes longevity. A prevalent mechanistic hypothesis explaining this effect suggests that protein degradation, including mitochondrial autophagy, is increased with CR, removing damaged proteins and improving cellular fitness. At steady state, increased catabolism must be balanced by increasing mitochondrial biogenesis and protein synthesis, resulting in faster protein replacement rates.

Silent information regulator 1 (SIRT1) is a type of histone deacetylase whose activity is dependent on nicotinamide adenine dinucleotide. SIRT1 plays a key role in the longevity effects elicited by calorie restriction. Recently, a neuroprotective effect of SIRT1 was reported for neurological diseases. The focus of this review is to summarize the protective effects of SIRT1 in cerebral ischemia. First, the posttranslational modifications of SIRT1 are illustrated; then, we discuss the roles of SIRT1 in cerebral immune homeostasis.

BACKGROUND & OBJECTIVES: Curcuma longa (turmeric) has a long history of use in Ayurvedic medicine as a treatment for inflammatory conditions. The purpose of the present study was to investigate the preventive effects of curcumin against acute pancreatitis (AP) induced by caerulein in mouse and to elucidate possible mechanism of curcumin action. METHODS: Curcumin (50 mg/kg/day) was intraperitoneally injected to Kun Ming male mice for 6 days, followed by injection of caerulein to induce AP.

Alzheimer's disease (AD) is characterized by progressive dysfunction of memory and higher cognitive functions with abnormal accumulation of extracellular amyloid plaques and intracellular neurofibrillary tangles throughout cortical and limbic brain regions. At present no curative treatment is available, and research focuses on drugs for slowing disease progression or providing prophylaxis. Withania somnifera (WS) also known as 'ashwagandha' is used widely in Ayurvedic medicine as a nerve tonic and memory enhancer.

PPARs are transcription factors belonging to the superfamily of nuclear receptors. PPAR-alpha is involved in the regulation of fatty acid (FA) uptake and oxidation, inflammation and vascular function, while PPAR-gamma participates in FA uptake and storage, glucose homeostasis and inflammation. The PPARs are thus major regulators of lipid and glucose metabolism. Synthetic PPAR-alpha or PPAR-gamma agonists have been widely used in the treatment of dyslipidaemia, hyperglycaemia and their complications. However, they are associated with an incidence of adverse events.