Antinociceptive Properties of Dichloromethane:Methanolic Leaf Extracts of Caesalpinia volkensii and Maytenus obscura in Animal Models

Abstract

The purpose of physiological pain is protection. Pain is associated with high morbidity and socioeconomic burden. Conventional medication of pain is expensive and arguably associated with various severe adverse effects hence the need to develop herbal agents that are effective as alternative. This study was designed to evaluate the antinociceptive of C. volkensii and M. obscura growing in Embu County, Kenya. Experimental animals were divided into four groups; normal group, diseased negative control group, diseased reference group and diseased experimental groups. Pain was induced into rats using formalin. The experimental groups were treated with leaf extracts of the plants at dose levels of 50 mg/kg, 100 mg/kg and 150 mg/kg. Anti-nociceptive activities in rats were compared with diclofenac (15 mg/kg) as the standard conventional drug. In antinociceptive study, the leaf extract C. volkensii reduced pain by between 6.82-15.24% only in the early phase while the leaf extracts of M. obscura reduced pain by between 12.39-34.81% (in the early phase) and between 6.4-12.4% (in the late phase). Diclofenac reduced pain by between 7.58-9.66% (in the early phase) and by 69.87% in the late phase. Further, the phytochemical screening results showed that the extracts of C. volkensii had flavonoids, steroids and phenolics while the leaf extracts M. obscura had phenolics, terpenoids and saponins. flavonoids. Therefore, the study has established that the DCM: methanolic leaf extracts of Caesalpinia volkensii and Maytenus obscura are effective in management of pain.