Antinociceptive Activity of Methanolic Stem Bark Extracts of Harrisonia Abyssinica Oliv and Landolphia Buchananii (Hallier F.) Stapf in Mice Model

Pain is an unpleasant sensation attributed to an interplay of sensory and cognitive mechanisms and thus a source of burden to the individual and society. Since pain acts as a source of discomfort, it requires medical suppression. There is a growing interest in the use of herbal remedies as an attractive healthcare alternative to synthetic drugs. This is due to conventional medications being expensive and arguably associated with various adverse effects, hence the necessity for herbal agents that are effective, safe and relatively cheap. Harrisonia abyssinica and Landolphia buchananii are herbs that have been utilized to manage various ailments afflicting people especially in tropical Africa. However, despite their wide folklore use, extensive literature research reveals limited evaluation on the pharmacological activities of their described effects on pain. Thus, the aim of the current study was to evaluate the antinociceptive effects of their methanolic extracts. Experimental mice were divided into a normal control group, a negative control group, a reference group and three dosage groups. The dosage groups were treated with stem bark extracts at concentration of 50 mg/kg, 100 mg/kg and 150 mg/kg. The formalin paw licking test was used to determine the antinociceptive potential. Evaluation of the antinociceptive activities was compared with diclofenac as the reference drug. The H. abyssinica extract reduced pain by 39.73%-81.13% (in the early phase) and 15.92%-69.84% (in the late phase) while L. buchananii extract reduced it by between 35.35%-47.72% (in the early phase) and 20.57-55.17% (in the late phase). In the early phase, reduction of pain by diclofenac was by 19.97%-46.50% and 76.77-74.80% (in the late phase). Several phytochemicals were observed to be present. The traditional medicinal use of the aforementioned plants in the suppression of pain has thus been confirmed by the study results.