Evaluation of Phytochemical Composition, Safety and Anti-Inflammatory Potential of Pseudocedrela kotschyi Harms (Meliaceae) Trunk Bark Extract

Abstract

Aim: Pseudocedrela kotschyi is a traditional medicine plant used by people in sub-Saharan regions to cure several diseases. The main objective of this study is to evaluate the Anti-inflammatory activity of the aqueous extract of Pseudocedrela kotschyi trunk bark. Methods: The aqueous extract was obtained by infusion of Pseudocedrela kotschyi trunk bark powder.  This aqueous extract was used for phytochemical tests, for the study of acute toxicity as well as for the study of anti-inflammatory activity.The acute toxicity study was assessed using the protocol 423 of the Organisation for Economic Co-operation and Development (OECD).The anti-inflammatory study was conducted using the method of Winter et al. The effects of the extract on inflammation were determined using carrageenan induced paw edema. For the acute toxicity study, four groups of three female Wistar albino rats each were formed, including a control group which received only distilled water while the other three groups received doses of 300, 2000 and 5000 mg/kg body weight of the aqueous extract respectively. Thirty (30) male and female Wistar albino rats were used for the study of anti-inflammatory activity. They were randomly divided into groups of six (6) animals each. One control group received distilled water, one group received indomethacin (reference drug) and the other three groups received 200, 150 and 100 mg/kg body weight of the aqueous extract respectively. Results: Phytochemical screening revealed the presence of alkaloids, flavonoids, catechic tannins, saponosides, polyphenols, quinones, terpenoids, oses and holosides whereas coumarins and gallic tannins are absent. In the acute toxicity study, oral administration of the aqueous extract of Pseudocedrela kotschyi trunk bark did not cause any death among the rats at doses up to 5000mg/kg body weight. According to the organisation for economic cooperation and development (OECD) 423 classification system, the lethal dose 50 (LD50) of such an extract is therefore greater than 5000mg/kg body weight. The study of anti-inflammatory activity revealed that the groups treated respectively with 200, 150 and 100 mg/kg body weight of extract significantly (P = 0.05) and dose-dependently inhibited the increase in edema compared with the normal control. The percentage increase in edema for these different doses of aqueous extract at the sixth hour was lower than that of the control group. They were 20.89 ± 0.73%, 21.36 ± 0.72% and 22.46 ± 1.16% respectively, compared with 35.03 ± 0.39% for the control group. Conclusion: The results obtained suggest that the aqueous extract of the trunk bark of Pseudocedrela kotschyi may contain biologically active principles with potential anti-inflammatory effects; thus supporting its use as a phytomedicine and buttressing the need for the isolation and identification of the biologically active constituent(s) of this plant.