Abstract:

BACKGROUND: Genistein is a soy product derivative that can prevent osteoporosis and inhibit cancer. There is no relevant report on its role in osteoarthritis.

OBJECTIVE: To study the effects of different doses of genistein on osteoarthritis and to explore its mechanism.

METHODS: A model of right knee osteoarthritis was established in male Wistar rats by using papain method. The experiment was divided into five groups: low, medium and high dose groups were administered with 4.5, 9, and 18 mg/(kg•d) genistein, respectively; a positive control group was given 15 mg/(kg•d) diclofenac sodium by gavage; and a control group was given pure water. Administration in each group was kept for 35 continuous days. The knee joint diameter of the right knee was measured on the 7^th, 14^th, and 21^st day after administration. At the 1^st, 3^rd, and 5^th week after administration, the levels of inflammatory factors in the right knee joint fluid were measured. Pure water, genistein colloid and 0.8% formaldehyde were separately applied to the skin surface of male Wistar rats to establish a skin irritation model. Redness and rash on the skin were then observed. The painful tumbling model of male Wistar rats was established by acetic acid method. The intervention method was the same as the knee osteoarthritis model. The number of limb tumbling in the rats within the first and the last 20 minutes was recorded to assess the analgesic effect. Ethic approval was obtained from the Animal Experiment Ethics Committee of Southern Medical University.

RESULTS AND CONCLUSION: At the same time point, the knee joint diameter of the middle and high dose groups and the positive control group was smaller than that of the control group (P < 0.05), and there was no significant difference between the first three groups (P > 0.05). At the same time point, the levels of matrix metalloproteinase-3, interleukin-6 and interleukin-1β were lower in the middle and high dose groups and the positive control group than in the control group (P < 0.05), and there was no significant difference between the first three groups (P > 0.05). Genistein gel did not result in induce rash and redness on the surface of the rat skin. In the first and the last 20 minutes, 9 and 18 mg/kg genistein could alleviate pain in rats, and its analgesic effect was similar to that of diclofenac sodium. All these findings indicate that genistein is not irritating to the skin and within a certain dose range, genistein can relieve pain and have anti-inflammatory, anti-swelling and anti-osteoarthritis effects.

Key words: bone, cartilage, rat, osteoarthritis, factor, experiment, anima