Antipyretic, anti-inflammatory and analgesic activity of Acacia hydaspica R. Parker and its phytochemical analysis

BACKGROUND: Inflammation and pain underlies several pathological conditions. Synthetic drugs used for the management of these conditions carry severe toxic effects. Globally efforts are ongoing to introduce novel medicinal plants to develop effective, economic and innocuous drugs. The current study was aimed at investigating the antipyretic, anti-inflammatory and analgesic activity of methanol extract of A. hydaspica aerial parts (AHM) and its active fraction. Furthermore identification and isolation of polyphenolic compounds was carried out to identify the active principles. METHODS: Yeast induced pyrexia, Paw edema, acetic acid-induced writhing and hot plate test were carried out in vivo. HPLC-DAD analysis and combination of different chromatographic techniques, involving vacuum liquid chromatography (VLC) and flash chromatography (FC) were carried out for chemical characterization. The structural heterogeneity of flavanols was characterized by ESI- MS, (1)H NMR, (13)C NMR and (2)D NMR spectroscopic analyses, and also by comparison with reported literature. RESULTS: Oral administration of A. hydaspica methanol extract (AHM) and A. hydaspica ethyl acetate fraction (AHE), showed dose and time dependent decrease in body temperature in yeast induced pyrexia, comparable to standard, Paracetamol. AHM and AHE (150 mg/kg) significantly (p < 0.001) inhibit pain sensation in various pain models, i.e. acetic acid induced writhing and hot plate test. Similarly AHM and AHE demonstrated an anti-inflammatory effect in carrageenan-induced paw edema in rats and 150 mg/kg dose being distinctly more effective (91.92% inhibition). When studied on prostaglandin E(2) (PGE(2)) induced edema in rats, AHM and AHE showed maximum inhibition of edema at 150 mg/kg after 4 h. HPLC chromatogram of AHM revealed the presence of gallic acid, catechin, rutin and caffeic acid. Chromatographic separation and structure characterization of AHE, has led to the identification of three flavan-3-ol derivative including 7-O-galloyl catechin, +catechin and methyl gallate, which have been reported for the first time in A. hydaspica. CONCLUSION: These results revealed that the presence of bioactive compounds in A. hydaspica might be responsible for the pharmacological activities, confirming the indigenous utility of A. hydaspica against inflammatory disorders.