In vivo effects of Ginkgo biloba extract on interleukin-6 cytokine levels in patients with neurological disorders

OBJECTIVE: To evaluate the effect of Ginkgo biloba extract (EGB) on the serum levels of cytokines in patients suffering from chronic, age-related neurological disorders (NDs). MATERIALS AND METHODS: Patients received 9.6 mg of EGB twice daily for 8 weeks. Serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay (ELISA) before and after treatment. RESULTS: The serum level of IL-6 was significantly higher in ND patients as compared to the healthy controls. After these patients underwent 4 and 8 weeks of EGB treatment, their IL-6 levels were shown a statistically significant (P<0.05) decline to near normal values. No significant changes were observed in serum levels of IL-1β and TNF-α after EGB treatment. We also observed an inverse relationship between ND and serum cholesterol levels. CONCLUSIONS: EGB may exert its beneficial effects in patients suffering from NDs through down-regulation and suppression of IL-6 secretion.