The inhibitory effect of Ruyizhenbao tablets on osteoarthritis pain / 中国药理学通报

Aim To investigate whether and how Huy- izhenbao tablets regulated osteoarthritis pain.Methods We transected the meniscotibial ligament of mice, which caused osteoarthritis by destabilizing the medial meniscus ( DMM).Different doses of Huyizhenbao tablets (12.5,25,50 mg • kg-1) were administered intragastrically.Dynamic and static mechanical allo- dynia were measured.The spinal cord slices were pre¬pared to record miniature excitatory postsynaptic cur-rents (niEPSCs) and miniature inhibitory postsynaptic currents (mlPSCs) by using patch clamp electrophysi¬ological recordings.The phosphorylation of NMDA re¬ceptor ( N-methyl-D-aspartate receptors) (rluNl sub- unit at S897 residue ( pS897-GluNl ) was observed by immunohistochemistry.Results Huyizhenbao tablets dose-dependently attenuated the dynamic and static mechanical allodynia induced by DMM, reduced the frequency of niEPSCs and inhibited the pS897-GluNI level.Huyizhenbao tablets had no effects on mlPSCs.Conclusions Huyizhenbao tablets effectively alleviate osteoarthritis pain by blocking the presynaptic release of excitatory transmitter glutamate and inhibiting the phosphorylation of NMDA receptor in spinal cord dorsal horn.

The regulating effect of Collybistin on Neuropathic Pain / 中国药理学通报

Aim To investigate the role of collybistin in the regulation of pain transmission. Methods The distribution of collybistin in spinal cord was observed by immunohistochemical staining. The role of collybis¬tin in pain transmission was evaluated by behavioral experiments. The effect of collybistin on inhibitory synap¬tic transmission was studied by electrophysiological ex¬periments. Results Collybistin was distributed in spi¬nal cord neurons; ShRNA-collybistin induced pain sen-sitization of intact mice ( P < 0. 05 ) . Overexpression of collybistin in spinal cord significantly alleviated pain sensitization induced by peripheral nerve injury ( P <0. 05 ) . ShRNA-collybistin also significantly reduced the amplitudes and frequencies of miniature inhibitory postsynaptic currents (mlPSCs) in superficial neurons of spinal cord dorsal horn (P <0. 05) . Overexpression of collybistin in spinal cord could reverse the effects of peripheral nerve injury on mlPSCs (P <0. 05). Con¬clusions Collybistin is involved in pain sensitization induced by peripheral nerve injury in mice.

The hepatoprotective effect of Aesculus hippocastanum seed extract against concanavalin A-induced acute liver injury in mice via inhibition of ROS and JNK pathway / 中国药理学通报

Aim To investigate the effect of Aesculus hippocastanum seed extract(AH) on concanavalin A (ConA)-induced acute liver injury in mice,and to ex-plore whether the mechanism was related to the inhibi-tory effect of AH on oxidative stress and c-Jun N-termi-nal kinase (JNK). Methods ConA(20 mg·kg-1) was administered via tail vein injecting to induce he-patic damage in mice. The groups of AH were given at 12.5,25,50 mg·kg-1by oral gavage separately for 20 days. The serum levels of AST,ALT,TP,and Alb were determined by automatic biochemical analyzer and the A/G ratio was calculated. TNF-α and IFN-γ levels were assayed by ELISA. The liver tissue was attained by HE and the histopathological changes were calculat-ed. The MDA, SOD, GSH contents of liver tissues were assayed by related kits. The activity of caspase-3 was detected by spectrophotometry. The expressions of cytochrome C and Bax, Bcl-2, p-JNK and p-Akt were detected by Western blot. Results The serum levels of ALT, AST, IFN-γ and TNF-α in AH groups were significantly lower than those in ConA-injured group, while the levels of TP,Alb and A/G were significantly higher. The SOD and GSH levels of liver tissues signif-icantly increased and MDA level decreased; liver his-topathological changes were consistent with those of the serological indicators, and AH treatment significantly reduced the pathological damage induced by ConA. In AH group,the expression of cytochrome C,caspase-3, Bax/Bcl-2 ratio and p-JNK markedly decreased, while the expression of p-Akt protein increased compared with ConA model group. Conclusion AH could sig-nificantly protect the ConA-induced acute liver injury in mice via inhibition of ROS and JNK pathway.

Curcumin inhibits advanced glycation end products-induced cell apoptosis and mitochondrial dysfunction via elevating PPARγ in chondrocyte / 中国药理学通报

Aim To explore the mechanism of the protective effect of curcumin on advanced glycation end products (AGEs)-induced chondrocyte apoptosis and mitochondrial dysfunction whether by elevating peroxisome proliferators-activated receptor-γ (PPARγ) or not.Methods The ratio of apoptotic cells was assayed by TUNEL;the mitochondrial membrane potential(△Ψm) was evaluated by Rhodamine-123 fluorescence.The ATP content was assayed by related kits.The activity of caspase-3 was detected by spectrophotometry.The expression of cytochrome C,Bax,and Bcl-2 was detected by Western blot.The PPARγ expression was determined by Western blot and real-time PCR;in addition,its activity was assayed by DNA-binding method.Results AGEs could induce chondrocyte apoptosis and up-regulate the levels of cytochrome C and caspase-3.Simultaneously,AGEs decreased the levels of △ Ψm and ATP production.Mitochondrial permeability conversion pore inhibitor cyclosporine A could significantly protect the cells from apoptosis.In addition,both PPARγ specific agonist pioglitazone and curcumin significantly inhibited AGEs-induced chondrocytes apoptosis and mitochondrial dysfunction.However,pretreatment with PPARγ specific inhibitor GW9662 (10 μ mol · L-1) could significantly antagonize the protective effect of curcumin on mitochondrial damage induced by AGEs.Curcumin could also significantly increase PPARγtranscriptional activity induced by AGEs,together with a significant induction of PPARγprotein and mRNA expression.Conclusion Curcumin could effectively protect AGEs-induced chondrocyte mitochondrial dysfunction by upregulating PPARγ,thus protecting chondrocytes from apoptosis.

Effect of acute stress stimulation on the seizure induction in epileptic model rats / 生理学报

This study was undertaken to observe the effect of acute stress on seizure occurrence in chronic period of epileptic model rats. Lithium-pilocarpine (LiCl-PILO)-induced epileptic rat model was constructed. At the spontaneous recurrent seizure period, acute stress stimulations such as cat's urine and foot electrical shock were applied to observe the behavioral changes and seizure occurrence. The results showed that after the cat's urine stimulation, the self-directed behaviors of the epileptic model rats decreased significantly, while the risk assessment behaviors increased significantly. The seizure occurrence, however, was not observed during the 45 min after the stimulation. Applying electrical foot shocks also did not evoke seizures in epileptic model rats. On the contrast, intra-peritoneal injection of low dose of pentylenetetrazole (PTZ, 30 mg/kg) evoked seizure more efficiently, and the duration of seizure activity was extensively prolonged in epileptic model rats than that of control rats. Taken together, these results indicate that although applying stress stimulations such as cat's urine and electrical foot shock cause several behavioral changes, they are not severe enough to evoke seizure in epileptic model rats.