Antioxidant and Antinociceptive Activity of Methanol Extract of Rhizomes of Iris Kashmairrania in Heat and Chemical-Induced Pain

Abstract

Pain is a sensation which in many cases represents the only symptom for the diagnosis of several disorders. Throughout ages man has used many different remedies for pain relief, among which medicinal herbs are most common due to their efficacy and relative safety due to their natural origin. Iris kashmiriana Baker (I. kashmiriana) is an important member of the family Iridaceae, locally known as Mazarmund in Kashmir valley. The plant owes its significance because of its endemic nature to the region and its use in alternative medicine as emetic, cathartic, diuretic and expectorant since long time. This study evaluated the antioxidant and antinociceptive effect of the methanolic extract of I. kashmiriana rhizomes in mice. Qualitative phytochemical screening of methanolic extract was carried out to identify the phytoconstituents. The In vitro antioxidant activity of methanolic extracts of I. kashmiriana rhizomes (IKME) was assessed against reducing power assay using standard protocols. The methanolic extract was assessed for antinociceptive activity using chemical and heat induced pain models such as hot plate and acetic acid-induced writhing test models in mice at the doses of 100 and 200 mg/kg (p.o.). Morphine sulphate (5mg/kg, i.p.) was used as reference analgesic drugs. The phytochemical screening results showed that the extract had flavonoids, steroids, saponins, phenolics and terpenoids which have been associated with anti-nociceptive activities. IKME demonstrated potent and dose-dependent antinociceptive activity in the chemical and heat induced mice models (p <0.001). Above findings suggest that I. kashmiriana rhizomes extract possesses significant antinociceptive activity in albino mice with reference to positive and negative control groups; however further studies on a large number of animals with clinical trials are required to confirm safe and effective use of this rhizomes extract in humans for pain purpose.

Keywords: Iris kashmiriana, Iridaceae, Morphine sulphate, Phytochemical screening, Antinociceptive.