Bee venom suppresses LPS-mediated NO/iNOS induction through inhibition of PKC-α expression

Ethnopharmacological relevanceBee venom (BV) is a traditional Korean medicine that has been widely used with satisfactory results in the treatment of some immune-related diseases, especially rheumatoid arthritis.Aim of the studyThe purpose of this study is to elucidate the molecular mechanism underlying the anti-inflammatory effects of BV, which is used in the treatment of various inflammatory diseases in traditional Korean medicine. We evaluated the anti-inflammatory effect of BV on NO generation and iNOS expression by LPS in rat C6 glioma cells.Material and methodsBV was obtained from the National Institute of Agricultural Science and Technology (NIAST) of Korea. Nitrite measurement, Immuno blot analysis, Reverse transcriptase-PCR and Electrophoretic mobility shift assay (EMSA) were used for assessment.ResultsBV suppressed the LPS-induced NO generation and iNOS expression, and it also inhibited the expressions of LPS-induced pro-inflammatory molecules including Cox-2 and IL-1β in rat C6 glioma cells. Then, BV inhibited LPS-induced expression of PKC-α and MEK/ERK, not p38 and JNK. Moreover, inhibition of LPS-induced iNOS expression by BV was dependent on transcriptional activities of AP-1/NF-κB through MEK/ERK pathway.ConclusionThese results indicate that BV suppresses LPS-induced iNOS activation through regulation of PKC-α. Accordingly, BV exerts a potent suppressive effect on pro-inflammatory responses in rat C6 glioma cells.