Rehmannia glutinosa inhibits tumour necrosis factor-alpha and interleukin-1 secretion from mouse astrocytes

We investigated whether an aqueous extract of Rehmannia glutinosa steamed r oot (RGAE) inhibits secretion of tumour necrosis factor-alpha (TNF-alpha) a nd interleukin-1 (IL-1) from primary cultures of mouse astrocytes. RGAE dos e-dependently inhibited the TNF-alpha secretion by astrocytes stimulated wi th substance P (SP) and lipopolysaccharide (LPS). IL-1 has been shown to el evate TNF-alpha secretion from LPS-stimulated astrocytes while having no ef fect on astrocytes in the absence of LPS. We therefore investigated whether IL-1 mediated inhibition of TNF-alpha secretion from astrocytes by RGAE. T reatment of RGAE to astrocytes stimulated with both LPS + SP decreased IL-1 secretion. Moreover, incubation of astrocytes with IL-1 antibody abolished the synergistic cooperative effect of LPS + SP. These results suggest that RGAE may inhibits TNF-alpha secretion by inhibiting IL-1 secretion and tha t RGAE has an anti-inflammatory activity in the central nervous system curi ng some pathological disease states. (C) 1999 Academic Press.