Abstract:
Despite the progress that has occurred in recent years in the development of therapies for pain, there is still a need
for effective and potent analgesics for pain. Pain is defined as unpleasant feeling essential for body’s defense system. It
acts as a warning signal against disturbances in the body. Conventional antinociceptives are expensive and have many
side effects. Continued use of these drugs may lead to tolerance and resistance. Medicinal plants have been used to
relieve pain and form a better alternative. Herbal antinociceptives are affordable and have arguably fewer side effects.
Carissa spinarum (Linn) is used to treat rheumatoid pain, fever and inflammation related disorders. This plant is used
locally by people in Embu County as analgesics. This study was designed to bioscreen the acetone leaves extracts
C.spinarum (Linn) for anti-nociceptive potential. The plant parts were collected from Siakago-Mbeere north sub-county,
Embu County, Kenya. The samples were prepared and extraction of the active compounds carried out using organic
solvent acetone in the ratio 1:2. Swiss albino mice were divided into five groups of five mice each: Normal, negative,
reference and experimental group. Pain was induced experimentally using formalin and acetic acid. The experimental
groups were treated with 50 and 100 mg/kg dose quantities of plant extract prepared. The acetone leaves extracts of
the plants were evaluated for antinociceptive properties in mice compared to the reference drug diclofenac sodium. Mice
were injected intraperitoneally with doses of the herbs, diclofenac and the vehicle. Thirty minutes later the animals were
injected with 0.01ml of 2.5% formalin in the sub planter region of the left hind paw and the other set with 0.4 ml of 5%
acetic acid. The total time spent lifting; biting, licking the paw and writhing were counted and scored. The acetone leaves
extracts tested at different dose levels lowered paw licking time in a dose dependant manner, Further, the phytochemical
screening results showed that the acetone leaves extracts of C. spinarum (Linn) possess anti-nociceptive activities. The
study has established that acetone leaves extracts of C. spinarum (Linn) are effective in management of pain.