Antipyretic and antinociceptive properties of dichloromethane: methanolic leaf and root bark extracts of carissa edulis (forssk.)Vahl in rats

ABSTRACT

Conventional medications are expensive, not easily available and arguably associated with various severe adverse effects hence the need to develop herbal agents that are effective as a complement. Carissa edulis (Forssk.)Vahl is the herb that has previously made thousands of people flock to a remote Loliondo village in Northern Tanzania, for its cure said to apply to all diseases such as cancer, HIV/AIDS, ulcers, hypertension, and diabetes. Although C. edulis (Forssk.)Vahl is widely used for pyrexia and pain in the traditional system of medicine, review of the literature show no scientifically investigated report of its described effects. This study was therefore designed to bioscreen the dichloromethane: methanolic extract of the leaf and root bark of C. edulis on antipyretic and anti-nociceptive potential on rats. The plant parts were collected from Siakago-Mbeere north subcounty, Embu County, Kenya. Experimental rats were divided in to four groups; normal group, diseased negative control group, diseased reference group and diseased experimental groups. Pain was induced experimentally using formalin while pyrexia was induced into the rats using turpentine. The experimental groups were treated with leaf and root bark extracts at concentration of 50mg/kg, 100mg/kg and 150mg/kg. Antipyretic and anti-nociceptive activities in rats were compared with aspirin (100mg/kg) and diclofenac (15mg/kg) as the standard conventional drugs, respectively. The leaf extracts reduced the rectal temperature by between 0.02% - 2.98% while the root bark extracts reduced it by between 0.15% - 2.55%. Aspirin reduced the elevated rectal temperature by between 1.08% - 2.53%. For antinociceptive study, the leaf extract reduced pain by between 47.04% - 47.19% (in the early phase) and 38.96% - 89.26% (in the late phase) while the root bark extracts reduced it by between 21.5% - 41.89% (in the early phase) and between 21.4% - 90.62% (in the late phase). Diclofenac reduced pain by between 27.37% - 34.9% (in the early phase) and 88.24% - 90.28% (in the late phase). Further, the phytochemical screening results showed that the extracts had alkaloids, flavonoids, steroids, saponins, phenolics and tepenoids. Alkaloids, flavonoids, and saponins have been associated with antipyretic and anti-nociceptive activities. Therefore, the study has established that the DCM: methanolic extracts of C. edulis (Forssk.)Vahl are effective in management of fever and pain.Therefore C. edulis can be explored as a possible bio-resource for generating an easily available herbal formulation that is more effective in the treatment of fever and pain.