Anti-inflammatory Activity of Leaf Extract and Fractions of Tapinanthus bangwensis (Engl. & K.Krause) Danser Parasitic on Citrus angustifolia

Abstract

Aim: This study was undertaken to evaluate the anti-inflammatory activity of extract of the leaves of the plant. Study Design: The study adopted the experimental design. Place and Duration of Study: Department of Pharmacology & Toxicology, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria, between 2014-2016. Methodology: The methanol extract (ME), obtained by cold maceration was fractionated in a silica gel column to afford n-hexane (HF), ethylacetate (EF) and methanol (MF) fractions. The extract and fractions were subjected to phytochemical analysis using standard methods. Acute toxicity (oral, intraperitoneal) and median lethal dose (LD50) of the extract was determined in mice. Acute anti-inflammatory activity of the extract and fractions was evaluated using topical acute edema of mouse ear induced by xylene and systemic acute edema of rat paw induced by carrageenan. Chronic anti-inflammatory activity was evaluated using formaldehyde arthritis test in rats and cotton pellet granuloma test in rats. Results: In topical acute inflammation, ME, EF and MF caused significant (P = .05, P < 0.01) inhibition of mouse ear edema and their effects were comparable to those of indomethacin. In systemic acute inflammation, ME, EF and MF produced significant (P = .05, P < .001) and sustained inhibition of the development of paw edema in rats. HF did not produce any significant edema inhibition in these models of inflammation. Studies in chronic inflammation showed that the extract and fractions caused significant (P = .05) inhibition of the global edematous response to formaldehyde arthritis in rats. They also significantly (P < .01) inhibited the formation of granuloma on implanted cotton pellets in rats. Conclusion: These findings show that T. bangwensis parasitic on C. angustifolia leaf extracts and fractions of increasing polarity possess anti-inflammatory properties in acute and chronic inflammation.