Effects of GBE50 on LPS/ATP induced NLRP3 inflammasome activation in primary rat microglia / 中国中药杂志

In this study, the anti-inflammatory mechanism of Ginkgo biloba extract 50 (GBE50) and its mechanism of action on NLRP3 inflammatory corpuscles were observed by primary microglia cells. LPS/ATP was used to stimulate microglia, and the best time for stimulation and optimal concentration of GBE50 were screened. Pro-inflammatory cytokine IL-1 and TNF-α was determined by ELISA. Western blot was performed to observe the protein expression of NLRP3, ASC, caspase-1 and IL-1 in cultured primary rat microglia. Effect of GBE50 on NLRP3 inflammatory corpuscle aggregation was detected by CO-IP. GBE50 (10 mg·L⁻¹) preconditioning could significantly inhibit the expression of LPS (100 μg·L⁻¹,12 h), ATP (5 mmol·L⁻¹, 30 min) induced primary microglia corpuscle associated protein, inflammatory corpuscle aggregation, and the release of inflammatory factors IL-6 and TNF-α. These results indicated that GBE50 could inhibit the secretion of inflammatory factors after microglia activation, which is related to down regulating the protein expression and activity of NLRP3 inflammatory corpuscle.

Ginkgo biloba extract 50 inhibited beta-amyloid-induced oxidative stress in rats' hippocampal neurons: an experimental study / 中国中西医结合杂志

<p><b>UNLABELLED</b>OBJECTIVE To study the in vitro effect and mechanism of Ginkgo biloba Extract 50 (GBE50) for inhibiting beta-amyloid (Abeta)-induced oxidative stress in rats' hippocampal neurons.</p><p><b>METHODS</b>The primary hippocampal neurons were cultured in vitro and divided into 4 groups, i. e. the normal control group (Ctrl), the Abeta group, the propanediol control group (PDO), and the six GBE50 concentrations groups (5, 10, 25, 50, 100, and 200 microg/mL). Excepted the Ctrl group, neurons were induced to oxidative stress by 20 gmolLAbeta25-35. The MTT and fluorescent probes labeling were used to observe the effect of GBE50 with different concentrations on the cell viability and the generation of intracellular reactive oxygen species (ROS) in neurons. Furthermore, Western blot was used to detect the cytoplasmic/total cytochrome C (Cyto C) ratio and total intracytoplasmal Cyto C, and the effect of the expression of oxidative stress-related protein Cyto C and activated Caspase-3 in three GBE50 concentrations groups (25, 50, and 100 microg/mL).</p><p><b>RESULTS</b>Compared with the Ctrl group, the cell vitality was obviously lowered and intracellular ROS generation significantly increased after induction of 20 micromol/L Abeta25-35 (both P < 0.05). Compared with the Abeta group, the cell vitality was evidently improved after treated with different GBE50 doses. Except for 10 microg/mL, the cell vitality could be obviously elevated along with increased drug concentrations (P < 0.05). Meanwhile, the intracellular ROS generation decreased significantly in each GBE50 dose groups (P < 0.05). Abeta could increase the cytoplasmic/total Cyto C ratio and enhance the activated Caspase-3 expression significantly (P < 0.05). Compared with the Abeta group, among the three concentrations of GBE50, the Cyto C ratio was obviously lowered in the 100 microg/mL GBE50 group (P < 0.05), and the expression of activated Caspase-3 significantly decreased in 50 microg/mL and 100 microg/mL GBE50 groups (P < 0.05).</p><p><b>CONCLUSIONS</b>20 micromol/L Abeta25-35 could induce the generation of intracellular ROS in hippocampal neurons. GBE50 could inhibit Abeta induced intracellular oxidative stress of neurons through lowering the cytoplasmic/total Cyto C ratio and inhibiting the activation of apoptosis protein Caspase-3 expression.</p>

Effects of Ginkgo biloba extract 50 on inflammatory cytokines and glia cell ultrastructures in the prefrontal cortex and hippocampus of aging rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the effects of Ginkgo biloba extract 50 (GBE50) on inflammatory cytokines and glia cell injury in the prefrontal cortex and hippocampus of aging rats and its probable mechanism. Methods Totally 45 male SD rats were randomly divided into 4 groups, i.e., the normal control group (n=12), the model group (n=11), the low dose GBE50 group (n=10), and the high dose GBE50 group (n=12). The aging rat model was intraperitoneally injected with D-galactose to establish the aging model for 42 days. Starting from the 22nd day of modeling, rats in the low dose GBE50 group and the high dose GBE50 group were administered by gastrogavage with 75 mg/kg and 150 mg/kg respectively. The protein contents and mRNA expressions of IL-1beta, IL-6, and TNF-a in the prefrontal cortex and hippocampus of rats were detected by radioimmunoassay and Real-time fluorescence quantitative PCR assay respectively. The ultrastructural changes of glia cells in the hippocampal CA1 region were observed by transmission electron microscope. Results The protein contents and mRNA expressions of IL-1beta and TNF-alpha in the prefrontal cortex and the hippocampus of aging rats obviously increased when compared with the normal control group (P < 0.05, P < 0.01). The content of IL-6 in the hippocampus of aging rats obviously decreased (P < 0.01). Compared with the model group, the protein content and mRNA expression of IL-1beta in the prefrontal cortex and the hippocampus were obviously downregulated in the low and high dose GBE50 groups. The content of TNF-alpha in the prefrontal cortex was obviously downregulated in the low and high dose GBE50 groups, the content of TNF-alpha in the hippocampus was obviously downregulated in the low dose GBE50 group (P < 0.05, P < 0.01). The content of IL-6 in the prefrontal cortex of the low dose GBE50 group was up-regulated. The content of IL-6 in the hippocampus of the high dose GBE50 group was also upregulated. The mRNA expression of IL-6 in the prefrontal cortex of the low and high dose GBE50 groups obviously increased (P < 0.05, P < 0.01). Low and high dose GBE50 showed obvious recovery on the ultrastructural damage of glia cells in the hippocampal CA1 region.</p><p><b>CONCLUSIONS</b>GBE50 showed inhibitive effects on the inflammatory reaction of nerves of aging rats. Its mechanism might be possibly correlated with its regulatory effects on the cytokines in the prefrontal cortex and the hippocampus, as well as the ultrastructures of glia cells in the prefrontal cortex and hippocampus to some degree.</p>

Effect of GBE50 on delayed rectifier potassium current of ventricular myocytes in ischemic guinea pig / 中国应用生理学杂志

<p><b>OBJECTIVE</b>Ginkgo biloba extract 50 (GBE50) is a new multicomponent drug with a polyvalent action extracted from the leave of Ginkgo biloba. The aim of this experiment was to study the effects of GBE50 on delayed rectifier potassium current (I(K)) in ventricular myocytes under normal and simulated ischemia conditions in guinea pigs.</p><p><b>METHODS</b>Single ventricular myocytes were isolated by an enzymatic dissociation method. I(K) were recorded by whole-cell patch clamp technique in voltage clamp mode. GBE50 was added to the perfusion chamber from low to high concentrations (25, 50,100 mg/L) in normal condition. Different concentrations of GBE50 (25, 50, 100 mg/L) were prepared with simulated ischemic fluid.</p><p><b>RESULTS</b>(1) Under normal condition, 100 mg/L GBE50 decreased I(K) (n = 7, P < 0.05). (2) Under ischemia condition, it was observed that I(K) was inhibited (n = 8, P < 0.05). (3) Perfusion with ischemia solution containing 50 mg/L (n = 8, P > 0.05) and 100 mg/L GBE50 (n = 6, P > 0.05) could reverse the decrease of I(K).</p><p><b>CONCLUSION</b>GBE50 significantly decreased I(K) in a concentration-dependent manner. GBE50 could alleviate the electrophysiological heterogeneity of myocardium to prevent ischemic myocardium from arrhythmia.</p>

Effect of precondition with GBE50 and Salviae miltionrrhizae on cycloxygenase-2 and its downstream effectors contents in ischemia/reperfusion myocardium / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate the changes in contents of cycloxygenase-2 (COX-2) and its downstream effectors in rat's myocardial ischemia/reperfusion (I/R) model and observe the effects of precondition with GBE50 (Ginkgo biloba extract 50) and Salviae miltiorrhizae (SM) on them.</p><p><b>METHODS</b>Rat's I/R model was established by 30-min left anterior descending coronary artery occlusion followed with 60-min reperfusion. Animals were divided into the model control group, the sham-operated group and the tested groups (received 1-week precondition with GBE50 and SM respectively via intragastric infusion before modeling). COX-2 mRNA expression in myocardium was detected by real-time PCR; contents of thromboxane B2 (TXB2) and 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha) were measured by radioimmunoassay.</p><p><b>RESULTS</b>The mRNA expression of COX-2 in the model group was obviously higher than that in the sham-operated group (P < 0.001), while that in the tested groups was down-regulated significantly (P < 0.01), and the content of TXB2 as well as the ratio of TXB2/PGF1alpha was reduced significantly (P < 0.05). Besides, SM also showed the up-regulation effect on 6-keto-PGF1alpha content in myocardium (P < 0.05).</p><p><b>CONCLUSION</b>COX-2 affects the myocardium through thromboxane A2 and prostacyclin after I/R; both GBE50 and SM can inhibit the production of COX-2, but they may act in different paths.</p>

The effect of ginkgolide B on action potential, L-type calcium current and delayed rectifier potassium current in ischemic guinea pig ventricular myocytes / 中国应用生理学杂志

<p><b>AIM</b>To study the effect of ginkgolide B from Ginkgo leave on action potential (AP), L-type calcium current (I(Ca) - L) and delayed rectifier potassium current (I(K)) in normal and ischemic guinea pig ventricular myocytes.</p><p><b>METHODS</b>With the standard microelectrode technique to record action potential and whole-cell variant patch-clamp technique to record calcium and potassium current.</p><p><b>RESULTS</b>(1) Under normal condition, ginkgolide B shortened APD and had no effect on RP, AP and V(max). Ginkgolide B also increased I(K) in a concentration dependent manner and had no significant effect on I(Ca) - L (2) Under ischemia condition, it was observed that shortening of APD, APA, decrease V(max) and depolarization of RP was induced by ischemia, but ginkgolide B could attenuate above--mentioned changes. (3) Under ischemia condition, I(Ca) - L and I(K) were inhibited, perfusion with ischemia solution containing ginkgolide B could reverse the decrease of I(Ca) - L and I(K).</p><p><b>CONCLUSION</b>Ginkgolide B had protective effect on ischemic myocardium to prevent ischemic arrhythmia.</p>

Effect of ginkgolide B on L-type calcium current and cytosolic Ca2+i in guinea pig ischemic ventricular myocytes / 生理学报

With whole-cell variant patch-clamp and laser scanning confocal microscope technique, we examined the effect of ginkgolide B (GB) from ginkgo leaves on L-type calcium current and cytosolic [Ca(2+)](i) in guinea pig ischemic ventricular myocytes. The results showed that under normal conditions, at a test voltage of 0 mV, GB had no significant effect on I(Ca,L); and during ischemia, the peak Ca(2+) current reduced by 37.71%, and the I-V curve of I(Ca,L) was shifted upward. 1 micromol/L GB reversed the change induced by ischemia, a result being significantly different from those of the ishemia group (P<0.05).Under control condition, 0.1,1,10 micromol/L GB decreased intracellular calcium concentration by 10.58%, 17.27% and 16.35% (n=12, 12, 10, P<0.01-0.001), respectively. With perfusion of ischemic solution for 12 min, intracellular calcium concentration increased by 20.15%. After a 12 min-perfusion of ischemic solution containing 1 micromol/L nifedipine or 5 mmol/L NiCl2, intracellular calcium concentration increased by 18.18% (P>0.05 vs ischemia) and 11% (P<0.05 vs ischemia), respectively. After 12 min of perfusion with ischemic solution containing 1 micromol/L GB, intracellular calcium concentration increased by 9.6% (P<0.05 vs ischemia). It is shown that GB could reverse the decrease of I(Ca,L) and partially inhibit calcium overload during ischemia.