Preparative Isolation and Characterization of Polyphenols from Alpinia galanga Linn Garcinia indica Choisy and Glycyrrhiza glabra Linn and Their Role as Anti obesity Therapeutics

Abstract

Obesity once considered to be the health issue of the West, is now on the rise even in India. The first line of prevention approach for the management of obesity is through diet, exercise and lifestyle modifications. These often pose a challenge to implement in practice and their failure to adequately control the condition leads to alternative treatment options including the drug intervention. Thus, there is a huge potential of the natural products in drug discovery and development. The experimental work compiled in this dissertation consists of two parts. In the first part, the phytochemical screening of selected plants was carried out. Spectroscopic characterization of isolated polyphenolic compounds was done on the basis of IR, UV, NMR and MS data. Preliminary docking studies on representative polyphenols were also carried out. In the second part, the effectiveness of polyphenol-rich fractions from A. galanga rhizomes, G. indica fruits and G. glabra roots as anti-obesity agents was undertaken using in vitro and in vivo models. MPLC based separation of the extract of A. galanga rhizomes resulted in the isolation of three phenolic compounds AG1-AG3, a steroidal compound AG4 and a diterpene compound AG5. Isolation of phytoconstituents using MPLC resulted in the isolation of three compounds that were elucidated to be 3and#8242;,4and#8242;,5,7-tetrahydroxy flavone (GA1), naphtha [1, 2-d] [1, 3] dioxole-6, 8-diol (GA2) and olean-5, 9(11), 12-trien-28-oic acid-3-ol-3-O-and#61538;-D-glucopyranose (GA3). MPLC based separation of the extract of G. glabra roots resulted in the isolation of three phenolic compounds, consisting of a flavanone, a phenyl propanoid and a catechin GG1, GG4 and GG5. Estimation of total phenolic (TPC) using Folin-Ciocalteu method, total flavonoid (TFC) using aluminium trichloride method, enzyme inhibition assays (Pancreatic lipase and alpha amylase using spectroscopic methods). High-fat diet (HFD) was used to induce obesity in experimental animals. There was a significant increase in body weight, body mass index (BMI),