FU-LING, A CHINESE HERBAL DRUG, MODULATES CYTOKINE SECRETION BY HUMANPERIPHERAL-BLOOD MONOCYTES

Fu-Ling, the sclederma of Poria cocos (Schw.) Wolf has long been used as a sedative and diuretic in traditional Chinese herbal medicine. Our study demonstrated that the substances extracted from Fu-Ling by 50% hot ethanol significantly augmented the secretion of interleukins IL-1 beta and IL-6 6 h after in vitro cultivation of human peripheral bloo d monocytes. The augmented effect was dose dependent. Tumour necrosis factor-alpha (TNF-alpha) secretion was also increased as the cells wer e treated with 0.4 mg/ml or higher doses of Fu-Ling extract. By contra st, Fu-Ling extract significantly suppressed the secretion of transfor ming growth factor-beta (TGF-beta) 3 h after the in vitro drug treatme nt. The suppressive effect was shown at doses as low as 0.2 mg/ml of F u-Ling extract. Since Fu-Ling extract enhanced the secretion of immune stimulators (IL-1 beta, IL-6 and TNF-alpha) but suppressed the secret ion of an immune suppressor (TGF-beta), the substance in 50% hot ethan ol extract of Fu-Ling might have potentiated the immune response. Fu-L ing extract was further fractionated by reverse-phase column chromatog raphy and high-performance liquid chromatography (HPLC). The component s showing activity in modulating the cytokine secretion were relativel y high in hydrophobicity.