Abstract

PRELIMINARY PHYTOCHEMICAL SCREENING, TOXICITY, ANTIHYPERGLYCEMIC AND ANALGESIC ACTIVITY STUDIES WITH CURCUMA LONGA LEAVES

Mohammad Nazmul Hasan, Aysha Ferdoushi, Nargis Ara, Shahnaz Rahman, Md. Shahadat Hossan, Mohammed Rahmatullah*

ABSTRACT

Background Curcuma longa is a plant whose rhizomes are used commonly as a spice, and the plant cultivated widely in the Indian sub-continent and many other countries of the world. The rhizomes reportedly possess glucose lowering and analgesic properties. The leaves of the plant are discarded; it was of interest to determine the antihyperglycemic and analgesic properties of the leaves. Methods Antihyperglycemic activity was determined through oral glucose tolerance tests (OGTT). Antinociceptive activity was determined by observed decreases in abdominal constrictions (writhings) in intraperitoneally administered acetic acid-induced pain model in mice. RESULTS Administration of methanol extract of whole plant led to dose-dependent reductions in blood glucose levels in glucose-loaded mice. At doses of 50, 100, 200 and 400 mg per kg body weight, the extract dose-dependently reduced blood glucose levels by 12.9, 21.7, 24.7, and 30.8%, respectively compared to control animals. By comparison, a standard antihyperglycemic drug, glibenclamide, when administered at a dose of 10 mg per kg body weight, reduced blood glucose level by 35.4%. In antinociceptive activity tests, the extract at doses of 50, 100, 200 and 400 mg per kg body weight reduced the number of abdominal constrictions by 24.1, 27.6, 31.0, and 34.5%, respectively. A standard pain relieving (antinociceptive) drug, aspirin, reduced the number of writhings by 31.0 and 51.7%, respectively, when administered at doses of 200 and 400 mg per kg body weight. CONCLUSION Antihyperglycemic and antinociceptive activities have not previously been reported for Curcuma longa leaves. The leaves can be a readily available mean for lowering blood sugar and for alleviating pain.

Keywords: Antihyperglycemic, Curcuma longa, OGTT, antinociceptive, Zingiberaceae