Heat stress can stimulate an increase in body temperature,which is correlated with increased expression of heat shock protein 70(HSP70) and tumor necrosis factor α(TNFα).The exact mechanism underlying the HSP70 and TNFα induction is unclear.Berberine(BBR) can significantly inhibit the temperature rise caused by heat stress,but the mechanism responsible for the BBR effect on HSP70 and TNFα signaling has not been investigated.The aim of the present study was to explore the relationship between the expression of HSP70 and TNFα and the effects of BBR under heat conditions,using in vivo and in vitro models.The expression levels of HSP70 and TNFα were determined using RT-PCR and Western blotting analyses.The results showed that the levels of HSP70 and TNFα were up-regulated under heat conditions(40 °C).HSP70 acted as a chaperone to maintain TNFα homeostasis with rising the temperature,but knockdown of HSP70 could not down-regulate the level of TNFα.Furthermore,TNFα could not influence the expression of HSP70 under normal and heat conditions.BBR targeted both HSP70 and TNFα by suppressing their gene transcription,thereby decreasing body temperature under heat conditions.In conclusion,BBR has a potential to be developed as a therapeutic strategy for suppressing the thermal effects in hot environments.
Brazilein is reported to have immunosuppressive effect on cardiovascular and cerebral-vascular diseases. The essential roles of innate immunity in cerebral ischemia are increasingly identified, but no studies concerning the influence of brazilein on the innate immunity receptors have been reported. The present study was designed to investigate the regulation of NOD2(Nucleotide-binding oligomerization domain-containing protein 2) by brazilein for its protection of neuron in cerebral ischemia in vivo and oxygen-glucose deprivation in vitro. The results showed that brazilein could reverse the elevated expression of NOD2 and TNFα(tumor necrosis factor alpha) elicited by cerebral ischemia and reperfusion. This reduction could also be detected in normal mice and C17.2 cells, indicating that this suppressive effect of brazilein was correlated with NOD2. The results from GFP reporter plasmid assay suggested brazilein inhibited NOD2 gene transcription. In conclusion, brazilein could attenuate NOD2 and TNFα expression in cerebral ischemia and NOD2 may be one possible target of brazilein for its immune suppressive effect in neuro-inflammation.
YAN Xiao-JinCHAI Yu-ShuangYUAN Zhi-YiWANG Xin-PeiJIANG Jing-FeiLEI FanXING Dong-MingDU Li-Jun
Objective: To explore the anti-nociceptive effect of patchouli alcohol(PA), the essential oil isolated from Pogostemon cablin(Blanco) Bent, and determine the mechanism in molecular levels. Methods: The acetic acid-induced writhing test and formalin-induced plantar injection test in mice were employed to con?rm the effect in vivo. Intracellular calcium ion was imaged to verify PA on mu-opioid receptor(MOR). Cyclooxygenase 2(COX2)and MOR of mouse brain were expressed for determination of PA’s target. Cellular experiments were carried out to find out COX2 and MOR expression induced by PA. Results: PA significantly reduced latency period of visceral pain and writhing induced by acetic acid saline solution(P<0.01) and allodynia after intra-plantar formalin(P<0.01) in mice. PA also up-regulated COX2 mRNA and protein(P<0.05) with a down-regulation of MOR(P<0.05) both in in vivo and in vitro experiments, which devote to the analgesic effect of PA. A decrease in the intracellular calcium level(P<0.05) induced by PA may play an important role in its anti-nociceptive effect.PA showed the characters of enhancing the MOR expression and reducing the intracellular calcium ion similar to opioid effect. Conclusions: Both COX2 and MOR are involved in the mechanism of PA’s anti-nociceptive effect,and the up-regulation of the receptor expression and the inhibition of intracellular calcium are a new perspective to PA’s effect on MOR.
