Journal of Veterinary and Applied Sciences

Evaluation of the analgesic and anti-inflammatory activities of methanol leaf extract of Heterotis rotundifolia

Kelechi G. Madubuike ¹*, Empress Oyongwo ¹, Aniefiok E. Udom ², Jessica I. Ukwueze ¹, Daniel C. Ifenkwe ¹, Macnissi U. Chima ¹ and Samuel O. Onoja ¹.1 Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, Michael Okpara University of Agriculture, Umudike.
² Department of Veterinary Medicine, College of Veterinary Medicine, Michael Okpara University of Agriculture, Umudike.

Abstract
The aerial part of Heterotis rotundifolia is used in ethnomedicine to relieve pain and inflammatory conditions. This study investigated the analgesic and anti-inflammatory effects of the methanol leaf extract of Heterotis rotundifolia (MLEHR) in albino rats. Air-dried pulverized leaves of H. rotundifolia (400 g) were extracted by cold maceration in two litres of 90% hydromethanol. An oral acute toxicity test of the extract was done following the up-and-down method. The analgesic potential of MLEHR (200, 400 and 800 mg/kg) was tested using the hot plate, tail flick and acetic acid-induced writhing tests. Its anti-inflammatory activity was investigated by means of the carrageenan-induced paw oedema and xylene-induced ear oedema models. The preliminary phytochemical analysis of MLEHR showed presence of flavonoids, alkaloids, saponins, tannins, carbohydrates, fats and oils. There was neither death nor signs of toxicity after 14 days of observation in the acute toxicity test, and the LD₅₀ was above 4,000 mg/kg body weight. The results of the hot plate model and acetic acid induced writhing showed a significantly (p < 0.05) higher pain reaction time and a significantly (p < 0.05) lower number of abdominal constrictions, respectively in the treated groups when compared to the untreated control. The tail flick test only showed significantly (p < 0.05) higher pain reaction time in the group treated with 800 mg/kg of the extract when compared to the untreated control. The extract at all the doses used in the treatment led to significantly (p < 0.05) lower oedema formation induced by carrageenan and xylene. The effects of treatment with MLEHR as recorded in this study validate the folkloric use of Heterotis rotundifolia to alleviate pain and inflammation.

Keywords: Heterotis rotundifolia; analgesic; anti-inflammatory; methanol extract.

How to cite this article:
Madubuike KG, Oyongwo E, Udom AE, Ukwueze JI, Ifenkwe DC, Chima MU and Onoja SO (2023). Evaluation of the analgesic and anti-inflammatory activities of methanol leaf extract of Heterotis rotundifolia. Journal of Veterinary and Applied Sciences, 13(2): 249 – 259.

* Correspondence: E-mail: madubuike.kelechi@mouau.edu.ng Phone: +2348036689778