Anti‐inflamatory Activity of Ethanol Leaf Extract of Hymenodictyon Floribundum (Hochst. & Steud) B. L. Rob in Rats: Impact of Inflammatory Biomarkers

Abstract

Introduction Hymenodictyon floribundum is a common shrub in Africa that has been used traditionally in the treatment of pain and inflammatory diseases. Phytomedicine has gained recognition as the epitome of alternative medicine and have been utilized for the search of many bioactive substances used as medicines (Sen and Samantha, 2014). There are over 30 species of Hymenodictyon and several ethnobotanical claims have pointed to the use of H. floribundum as an effective anti-inflammatory and analgesic plants. H. floribundum has been reported to have significant analgesic potential (Danraka et al., 2020), as such, its anti-inflammatory properties are worth investigating. Aim The aim of this study was to evaluate the anti-inflammatory effect of the ethanol leaves extract of H. floribundum in rats, as well as investigate it possible mechanism of anti-inflammatory action. Methods The inflammatory activity of the ethanol leaf extract of H. floribundum (HF) in rats was studied following phytochemical screening and LD50 determination. The extract at various doses (375, 750 and 1500 mg/kg p.o) was evaluated for inflammatory activity using carrageenan-induced inflammation model in rats. The involvement of inflammatory cytokines was investigated using ELISA kits by following manufacturer's instructions. Ethical Clearance: Ethical approval for the use of laboratory animal was obtained from Ahmadu Bello University Committee for Animal Use and Care. An approval number of ABUCAUC/2020/011 was given. All experiments were conducted in accordance with the guideline of National Institute of Health (NIH, 1998). Results The preliminary phytochemical screening of the extract revealed the presence of flavonoids, tannins, saponins, steroids glycosides, anthraquinones and phenols. The oral median lethal dose (LD50) of the extract in rats was found to be greater than 5,000 mg/kg body weight. The extract also significantly (p<0.05) reduced paw edema at the highest used doses (Fig.1.0). The levels of inflammatory cytokines were unaffected by the extract at all doses, except at the dose of 375mg/kg, where there was a significantly high levels of IL-6. (Fig.2.0). Conclusion Ethanol leaf extract of H. floribundum has significant anti-inflammatory activities, and this activity is not likely to be due to involvement of inflammatory cytokines.