0399

THE PROTECTIVE EFFECT AND ITS MECHANISM OF PUERARIN ON RAT ISLET INJURY INDUCED BY IL-1Β

Jia YJ, Zhou Y, Liu LX, Yang YJ

Xiangya Hospital, Central South University, Changsha, China

Objective: To investigate the protective effects of puerarin, a kind of compound isolated from a Chinese medicinal plant Pueraria Lobata, on islet injury induced by interleukin 1β(IL-1β).

Method: Islets of Langerhans from adult rats were preincubated for 24h with puerarin. Following stimulation with 200pg/ml IL-1β, media were removed for measuring nitric oxide (NO) production and accumulated insulin release. Islet viability was measured by acridine orange- propidium iodide (AO-PI) test. Moreover, p38 activation was analyzed by Western blotting; and inducible NO synthase (iNOS) mRNA was analyzed by reverse transcription-polymerase chain reaction (RT-PCR).

Results: The results showed that IL-1β was able to significantly increase NO production, reduce accumulated insulin release and islet viability. After 24h preincubated with 1mmol/L puerarin, it showed that a 42% decrease in NO production and a 2.4- and 3.7-fold increase in accumulated insulin release and islet viability, respectively. By Western blotting and RT-PCR assay, IL-1β was shown to activate p38, which controlled islet iNOS expression at the transcription level. Puerarin could inhibit IL-1β-indced p38 activation and reduce iNOS by 82%. However, 10μmol/L puerarin had no similar effect.

Conclusions: Puerarin can play some protective roles in islet injury induced by IL-1β. The mechanism may be related that puerarin inhibits IL-1β-indced p38 activation, and reduces islet NO synthesis by controlling iNOS gene transcription.