Phytochemical, Anti-Inflammatory, Antinociceptive, Antipyretic and Toxicity Analysis of Dichloromethane and Methanol Extracts of Five Selected Plants Using Animal Model

Abstract

Inflammation results from irritants causing body injury. Pain is discomfort associated with illness or injury while pyrexia can be defined as elevated body temperature. Common conventional anti-inflammatory, analgesic and antipyretic agents are expensive and have severe adverse effects. Traditional medicines are regarded by various communities as safe, efficacious with little or no adverse side effects. The study aim was to evaluate phytochemical profile, in vivo anti-inflammatory, antinociceptive, antipyretic activities as well as safety associated with Senna didymobotyra, Eucalyptus saligna, Bidens pilosa, Mangifera indica and Prunus africana. Plant samples were collected from Kanjagi sub - location, Kirima – Itune location, Giaki division, Meru County in Kenya. Extractions of phytochemicals were carried out using dichloromethane and methanol. Edema, pain and fever were induced in test animals using 1% carrageenan (0.5 ml), 2.5% v/v formalin (0.05 ml) and 20% v/v turpentine respectively. Wistar rats and albino mice were used in this study. The animal models were grouped into normal, negative, positive and experimental test groups I - III. Experimental test groups I, II and III were treated with 50, 100 and 150 mg/kg of the plant extract respectively. Anti-inflammatory and antinociceptive activities associated with extracts were evaluated against the standard anti-inflammatory and antinociceptive drug (Diclofenac), while antipyretic activities were established against aspirin. The herbal extract of Senna didymobotyra, Eucalyptus saligna, Bidens pilosa, Mangifera indica and Prunus africana and the reference drugs indicated some in vivo anti- inflammatory, antinociceptive and antipyretic effects. For anti-inflammatory activity, the extracts were associated with reduced hind paw diameter in relation to what was observed in control groups. The inhibitory rates observed in paw edema ranged from 1.59 - 11.05%, Diclofenac edema inhibition was ranging between 0.1 and 8.78%. For the analgesic study, the Senna didymobotyra, Eucalyptus saligna, Bidens pilosa, Mangifera indica and Prunus africana extract reduced paw licking time by 1.38-48.26% during early phase and between 28.45-83.90% during late phase while diclofenac pain inhibitory rates ranged between 12.20-80.20% in both phases. The herbal extract of Senna didymobotyra, Eucalyptus saligna, Bidens pilosa, Mangifera indica and Prunus africana were associated with 0.16 and 3.95% antipyretic activity while aspirin was associated with 1.52 and 3.60% antipyretic activities. The qualitative phytochemical evaluation indicated positive results for alkaloids, cardiac glycosides, flavonoid, saponins, steroids, tannins terpenoids and phenolics compound which are associated with anti-inflammatory, antinociceptive and antipyretic activities. The herbal extract of Senna didymobotyra, Eucalyptus saligna, Bidens pilosa, Mangifera indica and Prunus africana were not associated with any significant repeated dose toxicity at p<0.05. The study, confirms the role of Senna didymobotyra, Eucalyptus saligna, Bidens pilosa, Mangifera indica and Prunus africana extract by Meru community in disease management associated with inflammation, pain and fever. The results support the need to preserve or protect the biodiversity of the Senna didymobotyra, Eucalyptus saligna, Bidens pilosa, Mangifera indica and Prunus africana