Treatment Effects of Acetazolamide on Ischemic Stroke: A Meta-Analysis and Systematic Review

BACKGROUND

Ischemic stroke significantly contributes to high mortality and disability rates. Cerebral edema is a common consequence of ischemic stroke and can lead to aggravation or even death. Current treatment strategies are limited to decompressive craniectomy and the intravascular administration of hypertonic drugs, which have significant side effects. Acetazolamide (ACZ) plays a therapeutic role in cerebral edema by inhibiting aquaporin-4 (AQP-4) and improving collateral circulation. This study aimed to perform a meta-analysis and systematic review of ACZ therapy for ischemic stroke and evaluate its efficacy in animal models.

METHODS

We searched Embase, Cochrane Library, PubMed, Web of Science, Chinese National Knowledge Infrastructure, Wanfang Database, and Chinese Biomedical Literature Database until April 2023 for studies on ACZ in ischemic animal models. The quality of the animal trials was assessed using the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Stroke.

RESULTS

After screening 376 articles, only 5 studies were included. We found that ACZ reduced brain edema in cerebral ischemia 24 hours after onset (standard mean difference, -2.00; 95% confidence interval, -3.57 to -0.43, P = 0.01). ACZ also inhibited AQP-4 expression 24 hours after onset (standard mean difference-1.46; 95% confidence interval, -2.01 to -0.91, P < 0.001). Brain edema and AQP-4 expression also showed a declining trend on the third day after onset, although there were not enough data to support this. The effect of ACZ on brain ischemia in animals' neurological function is uncertain because of the limited research data.

CONCLUSIONS

ACZ inhibited AQP-4 and alleviated brain edema after ischemic stroke in the early stages but seemingly could not improve the neurological function.

[Safety and efficacy of transcatheter aortic valve replacement using the "All in One" single artery/vessel technique]

Objective: To explore the safety and efficacy of transcatheter aortic valve replacement (TAVR) using the "All in One" single-artery/vessel technique. Methods: This is a retrospective study. A total of 30 consecutive patients underwent TAVR using the single artery/vascular technique in Beijing Anzhen Hospital from August to December 2021 were included. Baseline clinical data, operative situation, postoperative outcomes, and incidence of adverse events during hospitalization and at one month post TAVR were analyzed. Results: Mean age was (72.6±9.7) years, 16 were male patients, STS score was (4.73±3.12)%. Four patients were diagnosed as isolated aortic regurgitation (all with tricuspid aortic valves), and 26 patients were diagnosed as aortic stenosis (AS), 10 of whom with tricuspid aortic valves and 16 of whom with bicuspid aortic valves. The single-vessel technique was applied in 3 aortic stenosis cases; the single-artery technique was applied in 27 cases. Echocardiography was performed immediately after procedure and results showed no or trace perivalvular leak in 27 cases and small perivalvular leak in 3 cases; the mean aortic transvalvular gradient of 26 AS patients decreased from (50.4±16.0) mmHg (1 mmHg=0.133 kPa) to (9.4±3.2) mmHg (P<0.001). The procedure time was (64.8±18.9) min. There were no intraoperative death, valve displacement, conversion to surgery, coronary artery occlusion in all 30 patients. There were no major cardiac adverse events such as myocardial infarction or stroke occurred during hospitalization or at follow-up. One-month follow-up echocardiography indicated prosthesis works well. The symptoms were significantly alleviated, and the Kansas City Cardiomyopathy Score (KCCQ score) of all patients increased from 48.1±18.4 to 73.5±17.6 (P<0.001). Conclusions: TAVR using the single artery/vessel technique is safe and feasible. This technique is related to reduced access complications and worthy of wide application.

[Potential short-term effects of tobacco control scheme under various application scenarios of tobacco control measures across the globe: a Meta-analysis]

Objective: based on summarizing the simulation and prediction of tobacco control measures across the globe and sorting out the various scenarios of tobacco control measures, the potential short-term effects of seven tobacco control measures in different scenarios were systematically analyzed. Methods: Until April 2022, PubMed, Embase, EconLit, PsychINFO, and CINAHL databases were used to retrieve literature about tobacco control measures simulation and prediction models across the globe. Inclusion and exclusion criteria were strictly followed. Meta-analysis for the potential short-term effects of seven tobacco control measures in different scenarios was performed using the R software. Results: A total of 22 papers covering 16 countries were selected. Five studies were conducted in the United States, three in Mexico, and two in Italy. There were all papers with the measures to tax increases, smoke-free air laws, and mass media campaigns, 21 papers with youth access restrictions, 20 with marketing restrictions, and 19 with cessation treatment programs and health warnings. The tax increases had diverse influences on the price elasticity of different age groups. The price elasticity in the age group 15-17 years was the highest, which was 0.044 (95%CI: 0.038-0.051). The potential short-term effects of smoke-free air laws in workplaces were higher than in restaurants and other indoor public places. The effects of youth access restrictions were greater in the age group <16 years than in the age group 16-17. The stronger the implementation of other measures, the greater the potential short-term effects. A comparison of seven tobacco control measures showed that the cessation treatment programs increase in cessation rate was the highest, 0.404 (95%CI: 0.357-0.456). The reduction in smoking rate and reduction in initiation rate of youth access restrictions strongly enforced and publicized was the highest in the age group <16 years, 0.292 (95%CI: 0.269-0.315), and 0.292 (95%CI: 0.270-0.316). Conclusions: The potential short-term effects of seven tobacco control measures in different scenarios were evaluated more accurately and objectively through Meta-analysis. In the short term, cessation treatment programs will substantially increase smoking cessation rates, and strong youth access enforcement will sharply reduce smoking and initiation rates among adolescents under 16. These results also offer strong data-related support for the simulation and prediction of tobacco control measures in China and other countries.

[Predictions of achievement of Sustainable Development Goal to reduce age-standardized mortality rate of four major non-communicable diseases by 2030 in China]

Objective: To predicate whether China can achieve the United Nations Sustainable Development Goals (SDGs) 3.4.1 to reduce the age-standardized mortality rate of four major non-communicable diseases (NCDs) in residents aged 30-70 years by 2030 based on the trend of the mortality from 1990 to 2019. Methods: We collected the mortality data on cardiovascular diseases, cancers, chronic respiratory diseases, and diabetes by age, gender and year in China from the Global Disease Burden Study 2019 (GBD2019). The age-period-cohort (APC) Bayesian model was applied for modeling the age-standardized mortality rate of four major NCDs in China during 2020-2030 according to the trend of the mortality during 1990-2019, and comparing the predicted value in 2030 with the observed value in 2015 to evaluate the possibility of achieving SDGs 3.4.1. Results: The age-standardized mortality rate of the four major NCDs in China showed a downward trend during 1990-2019. It is predicted that the number of death of the four NCDs in Chinese residents aged 30-70 years would increase from 2.96 million in 2020 to 3.19 million in 2030, while the age-standardized mortality rate would decrease from 308.49/100 000 in 2020 to 277.80/100 000 in 2030. The age-standardized mortality rate in 2030 would only decrease by 15.94% (18.73% for males and 14.31% for females) compared with 330.46/100 000 in 2015, with a 25.09% decrease for cardiovascular diseases, 4.76% for cancers, 37.21% for chronic respiratory diseases, and unchanged for diabetes. Conclusion: Although the age-standardized mortality rate of four major NCDs declined from 1990 to 2019 in China, it is difficult to achieve the SDGs of a 1/3 mortality rate reduction by 2030 according to the current declining trend, suggesting more active and effective efforts for NCD prevention and control are needed.

[Cardiometabolic disease patterns among elderly patients with colorectal cancer in China]

Objective: To explore the distribution patterns of cardiometabolic diseases (CMD) in elderly patients with colorectal cancer, and provide a reference for the prevention and treatment of cardiovascular metabolic diseases in these patients. Methods: Clinical data of 3 894 elderly patients with colorectal cancer from January 2008 to March 2018 admitted in the Chinese PLA General Hospital were recruited and the incidence rate of CMD was retrospectively analyzed. The influence factors of elderly patients with colorectal cancer combined with CMD were analyzed by multivariate Logistic regression model. Results: The morbidity rate of CMD in elderly patients with colorectal cancer is 33.4% (1 301/3 894), among them, the morbidity rate of the male was 31.9% (768/2 409), and that of the female was 35.9% (533/1 485). There was not significant difference between these two sex (P=0.074). The morbidity rates of CMD in patients of 65-74 years, 75-84 years and ≥85 years were 30.6% (754/2 462), 37.0% (479/1 294) and 49.3% (68/138), respectively, with significant differences (P<0.001). Multiple Logistic regression analysis revealed that female (OR=1.213, 95%CI: 1.056-1.394), age (75-84 years group: OR=1.344, 95%CI: 1.164-1.552; ≥85 years group: OR=2.345, 95%CI: 1.651-3.331) and body mass index (BMI 18.5-24.9 kg/m(2) group: OR=1.319, 95%CI: 1.065-1.638; ≥25 kg/m(2) group: OR=2.041, 95%CI: 1.627-2.561) were independent risk factors for elderly colorectal cancer patients with CMD. Conclusion: The morbidity rate of CMD in elderly patients with colorectal cancer increases with age and it is urgent to strengthen multidisciplinary cooperation and develop reasonable treatment plans to extend the survival and life quality of these patients.

Relative biological value of 1α-hydroxycholecalciferol to 25-hydroxycholecalciferol in broiler chicken diets

This study was conducted to evaluate the relative biological value (RBV) of 1α-hydroxycholecalciferol (1α-OH-D3) to 25-hydroxycholecalciferol (25-OH-D3) in one- to 21-day-old broiler chickens fed calcium (Ca)- and phosphorus (P)-deficient diets. On the d of hatch, 450 male Ross 308 broiler chickens were weighed and randomly allotted to 9 treatments with 5 replicates of 10 birds per replicate. The basal diet contained 0.50% Ca and 0.25% non-phytate phosphorus (NPP) but was not supplemented with cholecalciferol (vitamin D3). The levels of Ca and NPP in basal diets were lower than those recommended by NRC (1994). 25-OH-D3 was fed at zero, 1.25, 2.5, 5.0, and 10.0 μg/kg, and 1α-OH-D3 was fed at 0.625, 1.25, 2.5, and 5.0 μg/kg. The RBV of 1α-OH-D3 to 25-OH-D3 based on vitamin D intake was determined by the slope ratio method. Results showed that 25-OH-D3 or 1α-OH-D3 improved the growth performance and decreased the mortality in one- to 21-day-old broilers. A linear relationship was observed between the level of 25-OH-D3 or 1α-OH-D3 and mineralization of the femur, tibia, or metatarsus. The RBV of 1α-OH-D3 to 25-OH-D3 were 234, 253, and 202% when the weight, ash weight, and Ca percentage of femur were used as criteria. The corresponding RBV of 1α-OH-D3 to 25-OH-D3 were 232 to 263% and 245 to 267%, respectively, when tibia and metatarsus mineralization were used as criteria. These data indicate that when directly feeding a hormonally active form of vitamin D as 1α-OH-D3 proportionally less is needed than when using the precursor (25-OH-D3) in diets deficient in Ca and P.

1α-Hydroxycholecalciferol improves the growth performance and up-regulates the mRNA expression of vitamin D receptor in the small intestine and kidney of broiler chickens

1α-Hydroxycholecalciferol (1α-OH-D3) is a vitamin D derivative. The objective of this study was to evaluate the effects of 1α-OH-D3 on the growth and the mRNA expression of vitamin D receptor (VDR) in the small intestine and kidney of chickens. A total of 240 males of one-day-old Ross 308 broilers was randomly assigned to 4 treatments with 5 replicates of 12 birds per replicate. Three levels of 1α-OH-D3 (1.25, 2.5, and 5 μg/kg) were added to a basal diet containing 0.50% calcium (Ca), 0.25% non-phytate phosphorus (NPP), and without supplemental cholecalciferol (vitamin D3). The control diet contained 1.00% Ca, 0.45% NPP, and 25 μg/kg cholecalciferol. Dietary 1α-OH-D3 levels linearly improved the average daily feed intake (ADFI), average daily gain (ADG), femur and tibia mineralization, and plasma Ca concentration, and retained Ca and total phosphorus (tP) amounts in broilers from 1 to 21 d of age (P < 0.05). In addition, 1α-OH-D3 also linearly up-regulated the mRNA expression levels of VDR in the duodenum as well as those of VDR and sodium-phosphate cotransporter NaPi-IIa and NaPi-IIc in the kidney of broilers (P < 0.05). However, 1α-OH-D3 did not affect the mRNA levels of 25-hydroxylase in the liver or NaPi-IIb in the duodenum (P > 0.05). No differences were observed in the ADFI, ADG, bone length, plasma mineral concentration, retained tP amount, or the mRNA levels of the above genes (except for VDR in the kidney) between the birds fed the diet with 5 μg/kg 1α-OH-D3 and the birds fed the control diet (P > 0.05). By contrast, the weight, ash weight, ash percentage, and Ca percentage of the bone, retained Ca amount, and the mRNA level of VDR in the kidney were lower in the birds fed the diet with 5 μg/kg 1α-OH-D3 than in the birds fed the control diet (P < 0.05). These data indicate that 1α-OH-D3 up-regulates the gene expression of VDR in the small intestine and kidney at the transcriptional level, thereby improving the growth performance and bone mineralization of broiler chickens from 1 to 21 d of age.

Sasanquasaponin induces increase of Cl‑/HCO3‑ exchange of anion exchanger 3 and promotes intracellular Cl‑ efflux in hypoxia/reoxygenation cardiomyocytes

Anion exchanger 3 (AE3) is known to serve crucial roles in maintaining intracellular chloride homeostasis by facilitating the reversible electroneutral exchange of Cl‑ for HCO3‑ across the plasma membrane. Our previous studies reported that sasanquasaponin (SQS) can inhibit hypoxia/reoxygenation (H/R)‑induced elevation of intracellular Cl‑ concentration ([Cl‑]i) and elicit cardioprotection by favoring Cl‑/HCO3‑ exchange of AE3. However, the molecular basis for SQS‑induced increase of Cl‑/HCO3‑ exchange of AE3 remains unclear. The present study demonstrated that SQS activates protein kinase Cε (PKCε) and stimulates the phosphorylation of AE3 in H9c2 cells. Notably, SQS‑induced AE3 phosphorylation was blocked by the PKCε selective inhibitor εV1‑2, and a S67A mutation of AE3, indicating that SQS could promote phosphorylation of Ser67 of AE3 via a PKCε‑dependent regulatory signaling pathway. Additionally, both inhibition of PKCε by εV1‑2 and S67A mutation of AE3 eradicated the SQS‑induced increase of AE3 activity, reversed the inhibitory effect of SQS on H/R‑induced elevation of [Cl‑]i, Ca2+ overload and generation of reactive oxygen species, and eliminated SQS‑induced cardioprotection. In conclusion, PKCε‑dependent phosphorylation of serine 67 on AE3 may be responsible for the increase of Cl‑/HCO3‑ exchange of AE3 and intracellular chloride efflux by SQS, and contributes to the cardioprotection of SQS against H/R in H9c2 cells.

Effect of increased UV-B radiation on carotenoid accumulation and total antioxidant capacity in tobacco (Nicotiana tabacum L.) leaves

Carotenoids are important components of plant antioxidant systems, which protect photosystems from photooxidative destruction during ultraviolet-B (UV-B) exposure. The influence of carotenoids on total antioxidant capacity (TAC) of plants has rarely been studied. In this study, tobacco (Nicotiana tabacum L., 'K326') seedlings exposed to UV-B radiation were used in order to evaluate the effects of ambient levels of UV-B radiation on carotenoid accumulation. The aim was to investigate whether carotenoids could enhance TAC as a means of UV protection. Our results showed that leaf carotenoid content in the low UV-B exposure (+9.75 μW/cm2) plants was approximately 8% higher than that observed in control plants at 2-8 days of exposure. At high UV-B exposure (+20.76 μW/cm2), the carotenoid content increased rapidly after 1 day's exposure (10.41% higher than the control), followed by a return to the content as in control plants. Furthermore, carotenoid content positively correlated with TAC (P = 0.024). These results suggest that carotenoids have antioxidant properties and play an important role in the antioxidant system. UV-B exposure increased the carotenoid synthesis capability of plants. The plants could deplete the carotenoids to scavenge excess ROS at high UV-B radiation levels, which protects the tobacco plant from oxidative damage caused by UV-B stress.

Involvement of DJ‑1 in ischemic preconditioning‑induced delayed cardioprotection in vivo

DJ‑1 protein, as a multifunctional intracellular protein, has been demonstrated to serve a critical role in regulating cell survival and oxidative stress. To provide in vivo evidence that DJ‑1 is involved in the delayed cardioprotection induced by ischemic preconditioning (IPC) against oxidative stress caused by ischemia/reperfusion (I/R), the present study subjected male Sprague‑Dawley rats to IPC (3 cycles of 5‑min coronary occlusion/5‑min reperfusion) 24 h prior to I/R (30‑min coronary occlusion/120‑min reperfusion). A lentiviral vector containing short hairpin RNA was injected into the left ventricle three weeks prior to IPC, to knockdown DJ‑1 in situ. Lactate dehydrogenase (LDH) and creatine kinase‑MB (CK‑MB) release, infarct size, cardiac function, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities, malondialdehyde (MDA), intracellular reactive oxygen species (ROS), and DJ‑1 protein expression levels were assessed. IPC caused a significant increase in the expression levels of DJ‑1 protein. In addition, IPC reduced LDH and CK‑MB release, attenuated myocardial infarct size, improved cardiac function following I/R, and inhibited the elevation of ROS and MDA and the decrease in activities of the antioxidant enzymes SOD, CAT and GPx. However, in situ knockdown of DJ‑1 attenuated the IPC‑induced delayed cardioprotection, and reversed the inhibitory effect of IPC on I/R‑induced oxidative stress. The present study therefore provided novel evidence that DJ‑1 is involved in the delayed cardioprotection of IPC against I/R injury in vivo. Notably, DJ‑1 is required for IPC to inhibit I/R‑induced oxidative stress.

Enzyme activity and morphological change in the spleens of crucian carp in the Yongcheng coal mine subsidence area, China

The goal of the current study was to investigate the effects of pollution on aquatic organisms in the Yongcheng coal mine subsidence area. Crucian carp (Carassius auratus) were collected from Yongcheng natural fishpond (experimental group) and Tianmu Lake (control group), and the spleens were isolated for analysis. Subsequently, histological changes, DNA damage, and antioxidant enzyme activity were assessed. The result showed that there were more vacuoles, widened blood sinus cavities, increased partial dot necrosis, and a larger number of brown-yellow nodules in splenic sections stained with hematoxylin and eosin in the experimental group than in the control group. Additionally, it was not easy to distinguish red pulp from white pulp in the experimental group. The antioxidant enzyme activity in the experimental group was significantly lower than that in the control group (P < 0.01). Comet assay results showed varying degrees of tailing and DNA chain breaks in the experimental group, and further analysis demonstrated that the tail length and tail moment were significantly increased compared to those in the control group (P < 0.01). These results suggest that the spleen antioxidant defense system was severely damaged in crucian carp from the Yongcheng coal mine subsidence area.

Sasanquasaponin promotes cellular chloride efflux and elicits cardioprotection via the PKCε pathway

Sasanquasaponin (SQS) is an active component of Camellia oleifera Abel. A recent study by our group demonstrated that SQS was able to inhibit ischemia/reperfusion‑induced elevation of the intracellular chloride ion concentration ([Cl‑]i) and exerted cardioprotective effects; however, the underlying intracellular signal transduction mechanisms have yet to be elucidated. As protein kinase C ε (PKCε) is able to mediate Cl‑ homeostasis, the present study investigated its possible involvement in the effects of SQS on cardiomyocytes subjected to ischemia/reperfusion injury. Cardiomyocytes were pre‑treated with or without SQS or SQS plus εV1‑2, a selective PKCε inhibitor, followed by simulated ischemia/reperfusion (sI/R). The effects on cell viability, PKCε phosphorylation levels, [Cl‑]i, mitochondrial membrane potential and reactive oxygen species (ROS) production were assessed using an MTS assay, western blot analysis, colorimetric assays and flow cytometry. The results revealed that treatment with SQS prior to sI/R increased the viability of cardiomyocytes, and efficiently attenuated lactate dehydrogenase and creatine phosphokinase release induced by sI/R. In addition, SQS promoted PKCε phosphorylation and inhibited sI/R‑induced elevation of [Cl‑]i, paralleled by the attenuation of mitochondrial membrane potential loss and ROS generation. However, when the cardiomyocytes were treated with εV1‑2 prior to SQS pre‑conditioning, the cardioprotection induced by SQS was reduced and the inhibitory effects of SQS on sI/R‑induced elevation of [Cl‑]i, production of ROS and loss of mitochondrial membrane potential were also attenuated. These findings indicated that SQS may inhibit sI/R‑induced elevation of [Cl‑]i through the PKCε signaling pathway to elicit cardioprotection in cultured cardiomyocytes.

Evaluation of Relative Bioavailability of 25-Hydroxycholecalciferol to Cholecalciferol for Broiler Chickens

This study was conducted to evaluate the relative bioavailability (RBV) of 25-hydroxycholecalciferol (25-OH-D₃) to cholecalciferol (vitamin D₃) in 1- to 21-d-old broiler chickens fed with calcium (Ca)- and phosphorus (P)-deficient diets. On the day of hatch, 450 female Ross 308 broiler chickens were assigned to nine treatments, with five replicates of ten birds each. The basal diet contained 0.50% Ca and 0.25% non-phytate phosphorus (NPP) and was not supplemented with vitamin D. Vitamin D₃ was fed at 0, 2.5, 5.0, 10.0, and 20.0 μg/kg, and 25-OH-D₃ was fed at 1.25, 2.5, 5.0, and 10.0 μg/kg. The RBV of 25-OH-D₃ was determined using vitamin D₃ as the standard source by the slope ratio method. Vitamin D₃ and 25-OH-D₃ intake was used as the independent variable for regression analysis. The linear relationships between the level of vitamin D₃ or 25-OH-D₃ and body weight gain (BWG) and the weight, length, ash weight, and the percentage of ash, Ca, and P in femur, tibia, and metatarsus of broiler chickens were observed. Using BWG as the criterion, the RBV value of 25-OH-D₃ to vitamin D₃ was 1.85. Using the mineralization of the femur, tibia, and metatarsus as criteria, the RBV of 25-OH-D₃ to vitamin D₃ ranged from 1.82 to 2.45, 1.86 to 2.52, and 1.65 to 2.05, respectively. These data indicate that 25-OH-D₃ is approximately 2.03 times as active as vitamin D₃ in promoting growth performance and bone mineralization in broiler chicken diets.

DJ-1 is involved in the peritoneal metastasis of gastric cancer through activation of the Akt signaling pathway

Peritoneal metastasis is a major cause of death in patients with advanced gastric carcinoma. DJ-1 is now considered to play an important role in the metastasis of various malignancies. However, it remains largely unclear whether DJ-1 is involved in the development of peritoneal metastasis by gastric carcinoma. In the present study, we showed that the expression of DJ-1 was significantly upregulated in gastric cancer specimens with peritoneal metastasis compared to those without peritoneal metastasis. Knockdown of DJ-1 expression significantly inhibited invasion and migration, in vitro and the in vivo peritoneal metastatic abilities of SGC7901 gastric cancer cells. Moreover, knockdown of DJ-1 also diminished the expression of matrix metallopeptidase (MMP)-2 and MMP-9. All of these effects were reversed by restoration of DJ-1 expression. Following investigation of the pathway through which DJ-1 regulates cell invasion and migration, DJ-1 was found to cause phosphorylation of Akt in SGC7901 gastric cancer cells. Inhibition of the Akt pathway in SGC7901 cells mimicked the effects of DJ-1 knockdown on cell migration, invasion, MMP-2 and MMP-9 expression, and abolished the effects of DJ-1 in promoting SGC7901 cell invasion and migration. Taken together, the present study revealed that DJ-1 plays an important role in the development of peritoneal carcinomatosis from gastric carcinoma, at least partially through activation of the Akt pathway and consequent upregulation of MMP-2 and MMP-9 expression. Thus, DJ-1 may be a potential therapeutic target for peritoneal carcinomatosis of gastric carcinoma.

Nrf2-dependent upregulation of antioxidative enzymes: a novel pathway for hypoxic preconditioning-mediated delayed cardioprotection

It has been well demonstrated that hypoxic preconditioning (HPC) can attenuate hypoxia/reoxygenation (H/R)-induced oxidant stress and elicit delayed cardioprotection by upregulating the expression of multiple antioxidative enzymes such as heme oxygenase-1 (HO-1), manganese superoxide dismutase (MnSOD) and so on. However, the underlying mechanisms of HPC-induced upregulation of antioxidative enzymes are not fully understood. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an essential transcription factor that regulates expression of several antioxidant genes via binding to the antioxidant response element (ARE) and plays a crucial role in cellular defence against oxidative stress. Here, we wondered whether activation of the Nrf2-ARE pathway is responsible for the induction of antioxidative enzymes by HPC and contributes to the delayed cardioprotection of HPC. Cellular model of HPC from rat heart-derived H9c2 cells was induced 24 h prior to H/R. The results showed that HPC efficiently attenuated H/R-induced viability loss and lactate dehydrogenase leakage. In addition, HPC increased nuclear translocation and ARE binding of Nrf2 during the late phase, upregulated the expression of antioxidative enzymes (HO-1 and MnSOD), inhibited H/R-induced oxidant stress. However, when Nrf2 was specifically knocked down by siRNA, the induction of antioxidative enzymes by HPC was completely abolished and, as a result, the inhibitory effect of HPC on H/R-induced oxidant stress was reversed, and the delayed cardioprotection induced by HPC was also abolished. These results suggest that HPC upregulates antioxidative enzymes through activating the Nrf2-ARE pathway and confers delayed cardioprotection against H/R-induced oxidative stress.

[Effects of chuanxiong-chishao dispensing ratio on the pharmacokinetics of paeoniflorin in the canine]

OBJECTIVE

To explore the effects of dispensing ratio of Chinese herbs on the pharmacokinetic characteristics of effective components.

METHODS

Paeoniflorin (PF) in serum was determined by RP-HPLC with UV-detector. The concentration-time data were fitted using 3P87 Pharmacokinetic Program, and the pharmacokinetic parameters were compared by t-test.

RESULTS

The concentration-time curves of PF in both groups of Chuanxiong: Chishao 1:2 and 2:1 Xiongshao Pharmaceutics administrated intragastrically fitted open one compartment model. Parameters of Chuanxiong: Chishao 1:2 and 2:1 groups: Ka = 0.0082 +/- 0.0010 and 0.0088 +/- 0.0011(min-1), Ke = 0.0060 +/- 0.0015 and 0.0071 +/- 0.0008(min-1), t1/2Ka = 86.10 +/- 12.38 and 79.11 +/- 18.69(min), t1/2Ke = 119.95 +/- 27.23 and 98.14 +/- 10.82(min), tpeak = 169.16 +/- 21.18 and 149.39 +/- 29.51(min), Cmax = 3845.89 +/- 716.70 and 1635.81 +/- 230.95 (micrograms.L-1) respectively. The pharmacokinetic parameters of the two groups had no statistically significant differences (p > 0.05).

CONCLUSION

Different formulae of Chinese herbs do not always result in changes of pharmacokinetic characteristics of some one component.

Protective effect of tetramethylpyrazine against damages of aortic endothelial cells elicited by low-density lipoproteins

Effects of tetramethylpyrazine (TMP) on endothelial cells damaged by low-density lipoproteins (LDL) were investigated. When endothelial cells were incubated with LDL (1.5 mg protein.ml-1) the level of malondialdehyde (MDA) was increased and the activity of superoxide dismutase (SOD) was inhibited, and levels of cGMP and epoprostenol were decreased. TMP at concentrations of both 20 and 150 mg.L-1 nullified the inhibition of SOD activity and the reduction of cGMP and epoprostenol content elicited by LDL. However, the elevation of MDA content induced by LDL was negated by TMP only at 150 mg.L-1. TMP also caused a reduction in MDA content and an increase of epoprostenol level in normal endothelial cells. This study suggests that TMP protects endothelial cells against damages elicited by LDL and that the protection of TMP might be due to reduction in lipid peroxidation through stimulation of production and/or release of epoprostenol.

[Experimental study on the cardiotonic action of extract from Codonopsis pilosula (Franch.)Nannf]

Extracts of different concentrations from Codonopsis pilosula were administered to the myocardial cells of rats, and the results indicated that the activity of PDE was inhibited in different ways, and that cAMP was less hydrolyzed and increased in contents. When the extract was administered to the PRP of rabbits, the inhibiting rate of CaM activity rose with the increase of concentration in the extract.

Pseudolaric acids from Pseudolarix kaempferi

Three novel diterpenoids, pseudolaric acids A, B and C, were isolated from the root bark of Pseudolarix kaempferi Gorden used as an antifungal agent in folk medicine in China. The structures of pseudolaric acids B and C were assigned as 1 and 6 by spectral and chemical evidence. Pseudolaric acids A, B and C possess antifungal activity and pseudolaric acid B possesses an antifertility effect.