Pterostilbene protects against myocardial ischemia/reperfusion injury via suppressing oxidative/nitrative stress and inflammatory response

Recent studies have shown that pterostilbene (Pte) confers protection against myocardial ischemia/reperfusion injury. The oxidative/nitrative stress and inflammation induce injury after myocardial ischemia/reperfusion. The present study was designed to evaluate whether treatment with Pte attenuates oxidative/nitrative stress and inflammation in myocardial ischemia/reperfusion (MI/R). Rats were subjected to 30 min of myocardial ischemia and 3 h of reperfusion, and the rats were administered with vehicle or Pte. The results showed that Pte (10 mg/kg) dramatically improved cardiac function and reduced myocardial infarction and myocardial apoptosis following MI/R. As an indicator of oxidative/nitrative stress, myocardial ONOO⁻ content was markedly reduced after Pte treatment. And, Pte led to a dramatic decrease in superoxide generation and malondialdehyde (MDA) content and a dramatic increase in superoxide dismutase (SOD) activity. In addition, Pte treatment significantly reduced p38 MAPK activation and the expression of iNOS and gp91^phox and increased phosphorylated eNOS expression. Pte treatment dramatically decreased myocardial TNF-α, and IL-1β levels and myeloperoxidase (MPO) activity. Furthermore, ONOO⁻ suppression by either Pte or uric acid (UA), an ONOO⁻ scavenger, reduced myocardial injury. In conclusion, Pte exerts a protective effect against MI/R injury by suppressing oxidative/nitrative stress. These results provide evidence that Pte might be a therapeutic approach for the treatment of MI/R injury.     

Inhibition of p38 MAPK activation protects cardiac mitochondria from ischemia/reperfusion injury

Abstract

Context: Cardiac cell death and fatal arrhythmias during myocardial ischemia/reperfusion (I/R) can be reduced by p38 MAPK inhibition. However, the effects of p38 MAPK inhibition on cardiac mitochondria have not been investigated.

Objective: We tested the hypothesis that p38 MAPK inhibition at different times during I/R protects cardiac mitochondrial functions.

Materials and methods: Adult Wistar rats were subjected to 30?min of left anterior descending coronary artery (LAD) occlusion, followed by 120?min of reperfusion. A 2?mg/kg bolus infusion of p38 MAPK inhibitor, SB203580, was given before or during ischemia, or at reperfusion. Mitochondrial function and ultrastructure were assessed and Western blots were performed.

Results: Administration of SB203580 at any time point of I/R significantly attenuated the mitochondrial ultrastructure change, mitochondrial swelling, by increasing the absorbance at 540?nm (I/R control 0.42?±?0.03; pretreatment 0.58?±?0.04; during ischemia 0.49?±?0.02; at reperfusion 0.51?±?0.02, p?<?0.05), similar to reactive oxygen species (ROS) generation (I/R control 1300?±?48; pretreatment 1150?±?30; during ischemia 1000?±?50; at reperfusion 1050?±?55, p?<?0.05). Only SB203580 given before or during ischemia attenuated mitochondrial membrane depolarization (I/R control 0.78?±?0.04; pretreatment 1.02?±?0.03; during ischemia 1.05?±?0.12, p?<?0.05). In addition, pre-treatment of SB203580 significantly reduced the phosphorylation of p53, CREB, Bax, cytochrome c, and cleaved caspase 3.

Discussion and conclusion: The results from this study showed for the first time that p38 MAPK inhibition protects mitochondria from I/R injury.     

Magnesium lithospermate B reduces myocardial ischemia/reperfusion injury in rats via regulating the inflammation response

Abstract

Context: Magnesium lithospermate B (MLB), an active polyphenol acid of Danshen [Radix Salviae miltiorrhizae (Labiatae)], showed renoprotective, neuroprotective and myocardial salvage effects. Previous studies demonstrated that MLB could effectively suppress the production of cytokines and their associated signaling pathways in activated human T cells.

Objective: The purpose of this study was to examine the beneficial effects of MLB on myocardial ischemia/reperfusion (MI/R) injury and to explore its potential mechanisms related to anti-inflammation.

Materials and methods: Sprague–Dawley rats were grouped as sham group, model group and MLB-treated (15, 30 and 60?mg/kg) groups. Animals were subjected to MI/R injury by the occlusion of left anterior descending artery for 30?min followed by reperfusion for 3?h. At the end of reperfusion, blood samples were collected to determine the serum levels of cardiac troponin (cTnI), creatine kinase-MB (CK-MB), tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6). Hearts were harvested to assess infarct size, histopathological changes and the activity of myeloperoxidase (MPO). The expression of phosphor-IkB-α and phosphor-nuclear factor kappa B (NF-κB) were assayed by western blot.

Results: MLB administration significantly (p?<?0.05) reduced: (1) ST-segment elevation (0.23?mv), (2) the infarct size (22.5%), (3) histological scores of myocardial injury (1.67 score), (4) myocardial injury marker enzymes: cTnI (5.64?ng/ml) and CK-MB (49.57?ng/ml) levels, (5) pro-inflammatory cytokines: TNF-α (97.36?pg/ml), IL-1β (93.35?pg/ml) and IL-6 (96.84?pg/ml) levels, (6) MPO activity (1.82?U/mg), (7) phosphor-NF-κB (0.87) and phosphor-IkB-α (0.96) expression.

Discussion and conclusion: Our study provided evidence that MLB ameliorated the inflammatory process associated with MI/R injury via NF-κB inactivation.     

E-selectin in the pathogenesis of experimental myocardial ischemia-reperfusion injury

The role of E-selectin in the pathogenesis of an experimental model of myocardial ischemia-reperfusion injury was investigated. Pentobarbital anesthetized rats underwent left main coronary artery ligation (1 h) followed by reperfusion (1 h; MI/R). Sham operated rats were used as controls (sham MI/R). Myocardial ischemia-reperfusion injury reduced survival rate (50%), caused severe myocardial damage (necrotic area/area-at-risk 69.8 ± 5%; necrotic area/total=area = 56 ± 7.6%), increased serum creatine phosphokinase activity (sham MI/R = 33 ± 3 U/ml; MI/R = 215 ± 13 U/ml) and elevated myeloperoxidase activity (investigated as an index of leukocyte adhesion and accumulation; sham MI/R = 0.11 ± 0.02 U × 10⁻³/g tissue) in the area-at-risk (7.5 ± 1.7 U × 10⁻³/g tissue) and in the necrotic area (7.8 ± 2.2 U × 10⁻³/g tissue). Furthermore, MI/R rats had an increased pressure rate index, studied as a quantitative means for assessing myocardial oxygen demand. Administration of a hyperimmune serum containing antibodies against E-selectin significantly improved survival rate (80%), reduced myocardial injury (necrotic area/area-at-risk = 26.4 ± 7%, P < 0.005; necrotic area/total area 19.1 ± 2.8%, P < 0.005), lowered serum creatine phospokinase activity (85 ± 5 U/ml, P < 0.001) and decreased myeloperoxidase actibity in the area at risk (3.7 ± 1.3 U × 10⁻³/g tissue, P < 0.001) and in the necrotic area (3.0 ± 0.7 U × 10⁻³/g tissue). Finally, the administration of anti E-selection antibodies improved the PRI in MI/R rats. The present data suggest that E-selectin in vivo plays a key role in the pathogenesis of myocardial ischemia/reperfusion injury.     

The opposite effects of nitric oxide donor,S‐nitrosoglutathione,on myocardial ischaemia/reperfusion injury in diabetic and non‐diabetic mice

Nitric oxide is a potent anti‐apoptotic and cardioprotective molecule in healthy animals. However, recent study demonstrates that overexpression of eNOS exacerbates the liver injury in diabetic animals. whether diabetes may also alter NO's biologic activity in ischaemic/reperfused heart remains unknown. The present experiment was designed to determine whether the nitric oxide donor, S‐nitrosoglutathione, may exert different effects on diabetic and non‐diabetic myocardial ischaemia/reperfusion (MI/R) injury. Diabetic state was induced in mice by multiple intraperitoneal injections of low‐dose streptozotocin (STZ). The control or diabetic mice were subjected to 30 minutes ischaemia and 3 or 24 hours reperfusion. At 10 minutes before reperfusion, diabetic and non‐diabetic mice were received an intraperitoneal injection of S‐nitrosoglutathione (GSNO, a nitric oxide donor, 1 μmol/kg). GSNO attenuated MI/R injury in non‐diabetic mice, as measured by improved cardiac function, reduced infarct size and decreased cardiomyocyte apoptosis. In contrast, GSNO failed to attenuate but, rather, aggravated the MI/R injury in diabetic mice. Mechanically, the diabetic heart exhibited an increased nitrative/oxidative stress level, as measured by peroxynitrite formation, compared with non‐diabetic mice. Co‐administration of GSNO with EUK134 (a peroxynitrite scavenger) or MnTE‐2‐PyP5 (a superoxide dismutase mimetic) or Apocynin (a NADPH oxidase inhibitor) 10 minutes before reperfusion significantly decreased the MI/R‐induced peroxynitrite formation and the MI/R injury. Collectively, the present study for the first time demonstrated that diabetes may cause superoxide overproduction, increase NO inactivation and peroxynitrite formation, and thus convert GSNO from a cardioprotective molecule to a cardiotoxic molecule.     

丹酚酸B镁对兔急性心梗再灌注后无复流心肌损伤的保护作用

目的 评价丹酚酸B镁（salvianolic acid B,Sal-B）对兔急性心肌梗死再灌注后心肌损伤的保护作用。方法 新西兰大白兔40只随机分成4组,即假手术组、心肌缺血再灌注（myocardial ischemia/reperfusion,MI/R）、再灌注低剂量组（Sal-B20 mg·kg^-1组）、再灌注高剂量组（Sal-B 60 mg·kg^-1组）,每组10只。假手术组只开胸不结扎,其余3组结扎左室缘支90 min,切断结扎线120 min,建立MI/R模型。各组分别于结扎左心室缘支前5 min、结扎后90 min、再灌注120 min时取血,检测肌酸激酶同工酶（CK-MB）、心肌肌钙蛋白I （cTnI）,并评估缺血范围、无复流范围及梗死区心肌范围。结果 结扎90 min后,MI/R组、Sal-B 20 mg·kg^-1组和Sal-B 60 mg·kg^-1组3组之间CK-MB、cTnI水平差异无统计学意义。再灌注120 min后,Sal-B 60 mg·kg^-1组的血清CK-MB、cTnI水平显著低于MI/R组、Sal-B 20 mg·kg^-1组,差异有统计学意义（P<0.05）。各组染色所测的冠脉结扎区心肌缺血范围基本一致。与MI/R组、Sal-B 20 mg·kg^-1组比,Sal-B 60 mg·kg^-1组可以显著减少无复流面积（P<0.05）和梗死面积（P<0.05）,MI/R组和Sal-B 20 mg·kg^-1组之间差异无统计学意义。结论 Sal-B 60 mg·kg^-1能在一定程度上减轻心肌细胞结构损伤,缩小心肌梗死面积,减轻无复流的发生。     

Taxol prevents myocardial ischemia-reperfusion injury by inducing JNK-mediated HO-1 expression

Context: Ischemia/hypoxia and reperfusion impair mitochondria and produce a large amount of reactive oxygen species (ROS), which lead to mitochondrial and brain damage. Furthermore, heme oxygenase-1 (HO-1) as a cytoprotective gene protects cells against ROS-induced cell death in ischemia–reperfusion injury. Induction of HO-1 is involved in cytoprotective effects of taxol.

Objective: We hypothesize that taxol protects cardiac myocytes possibly by preserving myocardial mitochondrial function and inducing HO-1 expression through the JNK pathway.

Materials and methods: In this project, the perfused Langendorff hearts isolated from rats were randomly divided into five groups: control, ischemic, ischemic?+?taxol (0.1?μM), ischemic?+?taxol (0.3?μM), and ischemic?+?taxol (1?μM). Briefly, following a 15?min equilibration period, the control group was subject to normoxic perfusion for 120?min; the ischemia group, normoxic reperfusion for 120?min after 30?min ischemia; the taxol groups, normoxic reperfusion for 120?min after 30-min ischemia with taxol (0.1, 0.3, or 1?μM). The microtubule disruption score, ROS levels, and the activity of mitochondrial electron transport chain complexes I and III were examined by using immunohistochemical methods and free radical detection kits. Western blot assay was employed to study the underlying mechanisms.

Results: After Taxol treatment (0.1?µM), the ischemic microtubule disruption score was reduced to 9.8?±?1.9%. The study revealed that 0.1, 0.3, and 1?μM taxol reduced the level of ROS by 33, 46 and 51%, respectively (p?<?0.05). In additional, 0.3 and 1?μM taxol dramatically increased the activity of mitochondrial electron transport chain complex I (99.11?±?2.59, 103.49?±?3.89) and mitochondrial electron transport chain complex III (877.82?±?12.08; 907.42?±?16.21; 914.73?±?19.39, *p?<?0.05). Additionally, phosphorylation levels of JNK1 were significantly increased in the taxol group. Furthermore, the expression level of HO-1 increased with taxol treatments, which could be inhibited by the specific inhibitor of JNK, SP600125.

Discussion and conclusion: Taxol stabilized microtubules and effectively reduced ROS levels during ischemia. It also preserved the activity of mitochondrial complexes I and III. Interestingly, taxol induced the expression of HO-1 via the JNK pathway in cardiac myocytes.     

Association of Apolipoprotein E Polymorphism with Myocardial Infarction in Greek Patients with Coronary Artery Disease

Summary

Studies in several populations have indicated that genetic variation at the apolipoprotein E (apoE) structural locus influences the risk of coronary artery disease (CAD) and myocardial infarction (MI). This study aimed at investigating whether apoE polymorphism has an allelic and/or genotypic impact on the risk of MI in Greek patients with CAD. We compared apoE gene polymorphism in a group of patients with angiographically confirmed CAD but not MI [CAD/MI (–)-group, n?=?143] and a group of age and sex-matched CAD patients who had experienced a non-fatal MI [CAD/MI (+)-group, n?=?124]. The patients were also compared with a group of healthy younger individuals (n?=?240) with no family history of CAD.

The apoE genotype distribution differed significantly between the two groups of CAD patients (p?=?0.02). The ?2 allele was 5.3-fold less frequent in the CAD/MI (+)-group compared with the CAD/MI (-)-group (1.2% vs. 6.3%, p?=?0.01). The frequency of the ?2 allele in healthy subjects was 8.1%, which is 6.8-fold higher than in CAD/MI (+)-patients (p?=?0.001) and twice as high compared with all CAD patients (p?=?0.02). No differences in ?4 allele frequencies were observed between CAD/MI (+)- and CAD/MI (–)-patients (10.9% vs. 9.8%), or between patients with CAD and healthy subjects (10.3% vs. 10.2%).

In summary, the ?4 allele was not found to be associated with an increased risk for CAD or MI. In contrast, a negative association of the ?2 allele with MI was observed among Greek patients with CAD.     

Comparison of protective and curative potential of Daucus carota root extract on renal ischemia reperfusion injury in rats

Abstract

Context: Daucus carota Linn (Apiaceae), a useful vegetable, is traditionally used in treating kidney and hepatic dysfunctions.

Objective: To evaluate the protective and curative potential of D. carota root extract on renal ischemia reperfusion injury in rats.

Materials and methods: Wistar rats were selected with 8?+?8 groups (n?=?6). Renal pedicles of rats were occluded for 45?min and allowed for reperfusion period. In protective and curative studies, 14 days prior and 14 days after the induction of ischemia/reperfusion (I/R), rats received petroleum ether extract (PEE 250 and 500?mg/kg), fractional methanol extract (FME 250 and 500?mg/kg) and direct methanol extract (DME 250 and 500?mg/kg) of Daucus carota root, orally, once daily.

Results: PEE at a dose of 500?mg/kg significantly (p?<?0.001) reduced the levels of serum creatinine (0.853–3.090?mg/dl), uric acid (1.300–3.500?mg/dl) and urea (58.26–132.00?mg/dl) compared to disease control. FME at a dose of 500?mg/kg body weight significantly (p?<?0.001) reduced the levels of serum creatinine (0.960–3.090?mg/dl), uric acid (1.700–3.500?mg/dl) and urea (77.17–132.00?mg/dl) compared to disease control. DME at a dose of 500?mg/kg body weight significantly (p?<?0.001) reduced the levels of serum creatinine (1.173–3.090?mg/dl), uric acid (2.267–3.500?mg/dl) and urea (84.75–132.00?mg/dl) compared to disease control.

Discussion and conclusion: Findings demonstrate that postconditioning with the D. carota root extract significantly improves kidney function in I/R rats.     

Epigallocatechin-3-gallate counters cisplatin toxicity of rat testes

Context: Epigallocatechin-3-gallate (EG), the main active flavonoid in green tea, has well-known anti-inflammatory, antioxidant, and anti-apoptotic activities.

Objective: The EG protection against testicular injury induced by cisplatin was studied in Sprague–Dawley rats.

Materials and methods: Cisplatin (10?mg/kg, i.p) was given as a single injection to rats. EG was given at 40 and 80?mg/kg/day, i.p., for 5 days, starting the same day of cisplatin insult. Serum testosterone, and testicular malondialdehyde, total antioxidant status, nitric oxide, interleukin-6, interleukin-1β, cytochrome C, Bax/Bcl-2 ratio, and caspase-3 were measured. In addition, testicular histopathological examination and immunohistochemical expression of testicular tumour necrosis factor-α were evaluated.

Results: Cisplatin, compared to the control, significantly decreased serum testosterone (6.48?±?0.7 vs. 50.8?±?4.91?ng/10?mL), and testicular tissue antioxidant status (17.3?±?1.21 vs. 64.12?±?5.4?μmol/g), and significantly increased interleukin-6 (85.81?±?6.11 vs. 38.2?±?2.79?pg/100?mg), interleukin-1β (98.09?±?8.31 vs. 32.52?±?2.08?pg/100?mg), malondialdehyde (74.5?±?5.88 vs. 23.8?±?1.91?nmol/g), nitric oxide (104.98?±?8.5 vs. 52.68?±?5.12?nmol/100?mg), cytochrome C (5.97?±?0.33 vs. 1.6?±?0.99?ng/mg protein), Bax/Bcl-2 ratio (4.01?±?0.38 vs. 0.71?±?0.0), and caspase-3 (3.2?±?0.21 vs. 0.98?±?0.08?O.D. 405?nm) in rat testes. EG (40 and 80?mg/kg, respectively) caused significant increases of serum testosterone (33.9?±?2.89 and 47.88?±?4.4?ng/10?mL), and testicular antioxidant status (47.1?±?3.92 and 58.22?±?3.58?μmol/g), and significant decreases of interleukin-6 (57.39?±?4.2 and 48.18?±?3.98?pg/100?mg), interleukin-1β (65.12?±?5.88 and 41.96?±?3.51?pg/100?mg), malondialdehyde (42.3?±?3.9 and 28.67?±?2.49?nmol/g), nitric oxide (70.6?±?6.79 and 61.31?±?5.18?nmol/100?mg), cytochrome C (3.4?±?0.27 and 2.21?±?0.18?ng/mg protein), Bax/Bcl-2 ratio (1.49?±?0.14 and 1.1?±?0.09), and caspase-3 (2.1?±?0.17 and 1.48?±?0.13?O.D. 405?nm) in testes of cisplatin-treated rats. Additionally, both doses of EG significantly ameliorated the histopathological injury and reduced tumour necrosis factor-α expression in rat testes.

Conclusion: EG can afford testicular protection in cisplatin-challenged rats by its antioxidant, antinitrative, anti-inflammatory and antiapoptotic effects.     

Nephroprotective activity of Macrothelypteris oligophlebia rhizomes ethanol extract

Context: Macrothelypteris oligophlebia (Bak.) Ching (Thelypteridaceae) is a Chinese herbal medicine used traditionally for the treatment of diseases such as edema, boils, burns, and roundworms. However, research about the nephroprotective potential of this plant is not available.

Objective: Present study was designed to evaluate the protective effect of ethanol extract of M. oligophlebia rhizomes (EMO) on gentamicin (GM)-induced nephrotoxicity.

Materials and methods: Rats were intraperitoneal (i.p.) injected with GM (100?mg/kg) to induce nephrotoxicity and simultaneously EMO (250 and 500?mg/kg) was orally given to GM-treated rats for 8 days. Blood urea nitrogen (BUN), serum creatinine (Cr), malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were evaluated in renal tissues. Histopathological analysis was used for evaluation of the renal damage.

Results: Administration with GM-induced renal dysfunction in rats. Pre-treatment with EMO (500?mg/kg) significantly decreased the levels of BUN, Cr, MDA and NO (decreased BUN from 12.71?±?1.28 to 7.19?±?0.23 mmol/l, Cr from 39.77?±?5.34 to 19.17?±?0.90 μmol/l, MDA from 5.60?±?0.37 to 2.63?±?0.24 nmol/ml, and NO from 868.17?±?22.67 to 589.51?±?8.83 μmol/ml), and also restored the activities of renal antioxidant enzymes (SOD, CAT, and GSH-Px) (restored SOD from 1.59?±?0.17 to 2.94?±?0.13?U/mg protein, CAT from 3.22?±?0.34 to 10.57?±?0.27?U/mg protein, and GSH-Px from 9.11?±?1.29 to 20.72?±?1.83?U/mg protein).

Discussion and conclusion: Our results suggest that the rhizomes of M. oligophlebia potentially have a protective role in renal tissue against oxidative stress in acute renal failure.     

一种抗心肌缺血/再灌注损伤的新化合物的合成及心肌保护作用研究

在心肌缺血/再灌注 (MI/R) 时, 一氧化氮 (NO) 生成量减少, 氧自由基 (ROS) 大量堆积, 均可加重MI/R损伤。据此设计合成了可同时释放NO的ROS清除剂——乙酰阿魏单硝酸异山梨醇酯 (AFI), 并研究了AFI对MI/R大鼠的心肌保护作用及其作用机制。建立常规大鼠MI/R (30 min/3 h) 模型, 随机给予AFI (10 mg·kg^-1)、阿魏酸 (40 mg·kg^-1) 或单硝酸异山梨酯 (30 mg·kg^-1) 药物治疗 (ig), 再灌注末检测大鼠心肌梗死面积和心功能指标, 同时测定血清肌酸激酶、乳酸脱氢酶、超氧化物歧化酶活性、过氧化氢与丙二醛水平及NO含量。与阿魏酸钠、单硝酸异山梨醇单独治疗组或联合治疗组相比, AFI治疗组心肌梗死面积显著减小 (n = 8, P < 0.01), 左室发展压、左室等容收缩/舒张期压力上升或下降最大速率显著提高 (n = 8, P < 0.05), 血清肌酸激酶和乳酸脱氢酶活性显著降低。与阿魏酸钠或单硝酸异山梨醇单独治疗组相比, AFI治疗组血清超氧化物歧化酶活性增加、过氧化氢与丙二醛含量降低而NO含量显著升高 (n = 8, P均< 0.05)。这些结果表明, AFI这一新化合物可减轻大鼠MI/R损伤, 具有保护心脏功能, 其心肌保护作用比阿魏酸钠、单硝酸异山梨醇的单独使用或联合使用均强。     

5-Fluorouracil shell-enriched solid lipid nanoparticles (SLN) for effective skin carcinoma treatment

Context: The effective treatment of skin carcinoma is warranted for targeting the chemotherapeutic agents into tumor cells and avoiding unwanted systemic absorption.

Objective: This work was dedicated to the purpose of engineering highly penetrating shell-enriched nanoparticles that were loaded with a hydrophilic chemotherapeutic agent, 5-fluorouracil (5-FU).

Methods: Varying ratios of lecithin and poloxamer188 were used to produce shell-enriched nanoparticles by enabling the formation of reversed micelles within this region of the SLN. The localization of 5-FU within the shell region of the SLN, was confirmed using 5-FU nanogold particles as a tracer. SLN were introduced within sodium carboxy methylcellulose hydrogel, and then applied onto the skin of mice-bearing Ehrlich’s ascites carcinoma. The mice were treated with the gel twice daily for 6 weeks.

Results: The transmission electron microscope (TEM) revealed the formation of uniform nanoparticles, which captured reversed micelles within their shell region. The SLNs’ had particle size that ranged from 137?±?5.5?nm to 800?±?53.6, zeta potential of ?19.70?±?0.40?mV and entrapment efficiency of 47.92?±?2.34%. The diffusion of the drug-loaded SLN (269.37?±?10.92?μg/cm²) was doubled when compared with the free drug (122?±?3.09?μg/cm²) when both diffused through a hydrophobic membrane. SLN-treated mice exhibited reduced inflammatory reactions, with reduced degrees of keratosis, in addition to reduced symptoms of angiogenesis compared to 5-FU-treated mice.

Conclusion: SLN possesses the capacity to be manipulated to entrap and release hydrophilic antitumor drugs with ease.     

Effects of catalpol on the activity of human liver cytochrome P450 enzymes

Abstract

1. Catalpol possesses numerous pharmacological activities, and however, little data available for the effects of catalpol on the activity of human liver cytochrome P450 (CYP) enzymes.

2. This study investigates the inhibitory effects of catalpol on the main human liver CYP isoforms. In this study, the inhibitory effects of catalpol on the eight human liver CYP isoforms 1A2, 2A6, 2E1, 2D6, 2C9, 2C19, 2C8 and 3A4 were investigated in human liver microsomes.

3. The results indicated that catalpol could inhibit the activity of CYP3A4, CYP2E1 and CYP2C9, with IC₅₀ values of 14.27, 22.4 and 14.69?μM, respectively, but those other CYP isoforms were not affected. Enzyme kinetic studies showed that catalpol was not only a noncompetitive inhibitor of CYP3A4, but also a competitive inhibitor of CYP2E1 and CYP2C9, with Ki values of 7.40, 10.75 and 7.37?μM, respectively. In addition, catalpol is a time-dependent inhibitor for CYP3A4, with maximum inactivation (kinact) and 50% maximum inactivation (K_I) values of 0.02?min^?1 and 1.86?μM, respectively.

4. The in vitro studies of catalpol with CYP isoforms suggest that catalpol has the potential to cause pharmacokinetic drug interactions with other co-administered drugs metabolized by CYP3A4, CYP2E1 and CYP2C9. Further in vivo studies are needed in order to evaluate the significance of this interaction.     

Study of antidepressant-like activity of an enriched phloroglucinol fraction obtained from Hypericum caprifoliatum

Context: Hypericum caprifoliatum Cham &; Schlecht (Guttiferae) extracts have a potential antidepressant-like effect in rodents. However, the molecular mechanisms by which these extracts exert this effect remain unclear.

Objective: This study evaluated the effect of HC1, a fraction obtained from H. caprifoliatum enriched in phloroglucinol derivatives, on the Na⁺, K⁺ ATPase activity in mouse brain and verified the influence of veratrine on the effect of HC1 in the forced swimming test (FST).

Materials and methods: Veratrine (0.06?mg/kg) and HC1 (360?mg/kg) were given alone or combined i.p. 60 and p.o. 30?min, respectively, before FST. The effect of single and repeated administration (once a day for 3 consecutive days) of HC1 (360?mg/kg) on Na⁺, K⁺ ATPase activity was evaluated ex vivo in the cerebral cortex and hippocampus of mice subjected or not to FST.

Results: HC1 reduced the immobility time (103.15?±?18.67?s), when compared to the control group (183.6?±?9.51?s). This effect was prevented by veratrine (151.75?±?22.19?s). Mice repeatedly treated with HC1 presented a significant increase in Na⁺, K⁺ ATPase activity, both in cerebral cortex (46?±?2.41?nmol Pi/min?mg protein) and hippocampus (49.83?±?2.31?nmol Pi/min?mg protein), in relation to the respective controls (30?±?2.66 and 29.83?±?2.31?nmol Pi/min?mg protein respectively).

Discussion and conclusion: The HC1 antidepressant-like effect on FST might be related to its capacity to inhibit Na⁺?influx. HC1 increases hippocampal and cortical Na⁺, K⁺ ATPase activities possibly through long-term regulatory mechanisms.     

Protective effect of rutin against acute gastric mucosal lesions induced by ischemia-reperfusion

Abstract

Context: Rutin, a flavonoid commonly present in onions, apples and tea, has been suggested to have a variety of pharmacological activities, including immunomodulator, anti-inflammatory and antioxidant activities.

Objectives: The present study was to examine the protective effects of rutin on gastric mucosal damage induced by gastric ischemia-reperfusion (I/R) in rats.

Materials and methods: Rutin (50, 100, 200?mg/kg) was administered intragastrically for five consecutive days before ischemia. Sixty minutes after the last administration of rutin, under anesthesia, the celiac artery was clamped for 30?min, and then the clamp was removed for 60?min reperfusion. After reperfusion, the stomach was removed for biochemical and histological examinations.

Results: As compared with the I/R group (116.7?±?21.5), administration of rutin at doses of 50, 100 and 200?mg/kg significantly prevented the increase of gastric mucosal injury index induced by gastric I/R (73.4?±?14.8, 65.9?±?9.6 and 26.9?±?5.7, respectively). ED₅₀ value was 138.7?mg/kg. Moreover, rutin at doses of 50, 100 and 200?mg/kg showed an inhibition on the increased myeloperoxidase (24.6, 41.3 and 53.1% reduction) activity and malondialdehyde levels (27.4, 40.3 and 50.7% reduction) in gastric mucosa. Also, the elevation of inducible NO synthase (iNOS) activity as well as the decrease of constitutive NO synthase (cNOS) in the gastric mucosa were significantly prevented by rutin pretreatment.

Conclusion: These results suggested that rutin has a protective effect against gastric mucosal injury induced by gastric I/R and that the gastroprotection was related to the NOS/NO pathway and its antioxidant activity.     

Hesperidin,a citrus flavonoid,protects against l-methionine-induced hyperhomocysteinemia by abrogation of oxidative stress,endothelial dysfunction and neurotoxicity in Wistar rats

Context: Hesperidin (HSP), a flavanoglycone found in citrus fruits, has antioxidant, anti-inflammatory and neuroprotective properties.

Objective: This study evaluates the protective effect of HSP on l-methionine-induced hyperhomocysteinemia (HHcy) in rats.

Materials and methods: Male Wistar rats were randomly divided into seven groups as DMSO, l-methionine, HSP (25, 50 and 100?mg/kg), HSP-per se (100?mg/kg) and donepezil (0.1?mg/kg). HHcy was induced by oral administration of l-methionine (1.7?g/kg) for 32 days. From the 14^th day of study HSP (25, 50 and 100?mg/kg) and donepezil was administered orally to l-methionine-treated rats. Cognitive impairment induced by HHcy was determined using the Morris water maze (MWM) and Y-maze on video tracking system (28^th–32^nd day). Different biomarkers of HHcy in serum and brain and vascular reactivity were evaluated and histopathology (thoracic aorta and brain) was done.

Results: HSP (100?mg/kg) treatment in l-methionine-treated rats exhibited significant (p?p?l-methionine on acetylcholine-induced endothelial-dependent relaxation and increased serum nitrite and vascular nitric oxide bioavailability along with the restoration of histological aberrations.

Conclusion: HSP exerts a protective effect on HHcy by abrogating oxidative stress, ED and neurotoxicity.     

Effects of the hydroalcoholic extract of Rosa damascena on learning and memory in male rats consuming a high-fat diet

Context: High-fat diet (HFD) can cause deficits in learning and memory through oxidative stress and increase Alzheimer disease risk. Rosa damascena Mill. (Rosaceae) extract possesses potent antioxidant properties.

Objective: This study investigated the effects of the hydroalcoholic extracts of petals of R. damascena on learning and memory in male rats consuming an HFD.

Materials and methods: Forty male Wistar rats (200–250?g) were randomly assigned to four groups: control, R. damascena extract, HFD and HFD?+?extract. The extract (1?g/kg bw daily) was administered by oral gavage for 1?month. Animals were allowed free access to high-fat chow for 3?months. The Morris water maze and the passive avoidance learning tests were used to assess learning and memory.

Results: In the passive avoidance learning test, the step-through latencies in the retention test (STLr) of the extract (147.4?±?23.3) and HFD (150.3?±?25.2) groups were significantly lower than those of the control group (270.4?±?10.5) (respectively, p?p?p?p?Discussion and conclusion: Our results indicate that, while HFD or R. damascena extract alone leads to memory deficits, R. damascena extract exerted a positive effect on HFD-induced memory deficits. We hypothesize that the observed effects of R. damascena extract are likely due to its strong antioxidant properties.     

Hematological and lipid profile evaluation of a hexane fraction of Costus afer leaves in arthritic rats

Abstract

Context: Costus afer Ker Gawl. (Costaceae) is an ethnomedical plant used as therapy against inflammatory disorders.

Objective: The objective of this study was to evaluate the hematological and lipid profile analysis of hexane fraction of C. afer leaves (CAHLF) in arthritic rats.

Materials and methods: Male albino rats were randomly distributed into seven groups of six rats each. Rats were induced with arthritis using formaldehyde and Complete Freund’s Adjuvant (CFA) for 7 and 21?d, respectively. The animals were administered orally with 50, 100, and 250?mg/kg CAHLF, 10?mg/kg diclofenac and prednisolone, 0.9% NaCl (control), and 0.9% NaCl (normal). At the end of treatment periods, blood samples were withdrawn and subjected to hematological and biochemical analysis using auto-analyzer and spectrophotometric methods.

Results: Hematological analysis revealed that in formaldehyde- and CFA-induced arthritic rat models, 250?mg/kg CAHLF-treated groups had significantly reduced (p?<?0.05) hematocrit counts (HC) (30.98?±?1.59% and 33.55?±?1.10%), white blood cell counts (WBC) (5.50?±?0.35 and 4.15?±?0.82?×?10⁹/L), and platelet counts (PC) (401.50?±?48.94 and 246.33?±?5.54?×?10⁹/L) compared with control HC (46.90?±?1.92 and 41.88?±?2.19%), WBC (11.09?±?0.26 and 7.37?±?0.34?×?10⁹/L), and PC (783.67?±?59.51 and 593.83?±?36.3?×?10⁹/L). Furthermore, blood analysis showed that CAHLF-treated groups had reduced total cholesterol, low-density lipoprotein cholesterol, and triglycerides while they had an elevated high-density lipoprotein compared with the control group.

Discussion and conclusion: Findings from this study indicated that CAHLF could possess immunomodulatory and hypolipidemic properties in arthritic rats. CAHLF could be considered as a source of biopharmaceutical agents in anti-arthritis drug discovery process.