Pain Relieving Effects of KHA-30 as a Herbal Medicine in an Animal Model of Arthritis

Abstract

BACKGROUND: Herbal medicine has traditionally been used in oriental medicine to relieve pain. Arthritis, accompanied with severe pain, became the most prominent disease as more people live to advanced ages. In the present study, the effect of KHA-30 was examined in an animal model of arthritic pain induced by the injection of carrageenan into the knee joints of the rat. METHODS: Adult male Sprague-Dawley rats were used. Under urethane anesthesia, the arthritis was induced by the injection of 2% carrageenan into the left knee joint cavity of rats. To record neuronal activity of articular nerve afferents, the saphenous nerve was cut distally from the knee joint and centrally in the inguineal region. The left femur and tibia were fixed by a grip, and a mineral oil pool was made. The left saphenous artery was cannulated in order for to administer the KHA-30. Nerve fibers were characterized by their mechanical sensitivity to passive movement of the joint consisting of outward and inward movements. RESULTS: Intrarterially injected KHA-30 significantly reduced the duration of neural responses of the afferents in response to mechanical stimulation. And KHA-30 also significantly inhibited the number of neural responses to mechanical stimulation. CONCLUSIONS: These results indicate that KHA-30 may be effective in relieving arthritic pain as a herbal medicine and useful as one of the analgesics.