Influence of cerebral ischemia and post-ischemic reperfusion on mitochondrial oxidative phosphorylation

Unilateral ischemia in the right cerebral hemisphere of the rat was induced by ligation of the right common carotid artery coupled with controlled hemorrhage to produce hypotension (25±8 mm/Hg). Where indicated after 30 min of ischemia, the withdrawn blood was reinfused to restore arterial pressure to normal. Mitochondria isolated from the ipsilateral hemisphere after 30 min of ischemia showed significantly lower respiratory rates than the organelles isolated from the contralateral side. Oxidation of NAD⁺-linked substrates was more sensitive to inhibition in ischemia (30%) than was of ferrocytochromec (12%), succinate oxidation being intermediate. The activities of membrane-bound dehydrogenases (both NADH and succinate-linked) were also significantly lowered. Ischemia did not affect the cytochrome content of mitochondria. Respiratory activity (NAD⁺-linked) of mitochondria isolated from the ipsilateral hemisphere was twice as sensitive to inhibition by fatty acid as was of preparations from the contralateral side. Mitochondria isolated from cerebral cortex after 90 min of post-ischemic reperfusion showed no significant improvement in the rate of substrate oxidation. Adenine nucleotide translocase activity and energy-dependent Ca²⁺ uptake, both of which decreased significantly in mitochondria isolated from the ischemic brain, showed little recovery, on reperfusion. These observations suggested the strong possibility that the deleterious effects of ischemia on mitochondrial respiratory function might be mediated by free fatty acids that are known to accumulate in large amounts in ischemic tissues. The pattern of inhibition of ATPase activity was consistent with this view.     

Effect of Azadirachta indica on paracetamol-induced hepatic damage in albino rats.

Azadirachta indica, a plant used widely in Ayurveda, has been reported to have anti-inflammatory, immunomodulatory and adaptogenic properties. The present study evaluates its hepatoprotective role. Fresh juice of tender leaves of Azadirachta indica (200 mg/kg body wt. p.o.) inhibited paracetamol (2 g/kg body wt. p.o.)-induced lipid peroxidation and prevented depletion of sulfhydryl groups in liver cells. There was an increase in serum marker enzymes of hepatic damage (aspartate transaminase, alanine transaminase and alkaline phosphatase) after paracetamol administration. Azadirachta indica pretreatment stabilized the serum levels of these enzymes. Histopathological observations of liver tissues corroborated these findings.     

印楝的组织培养

1　植物名称　印楝 (Azadirachtaindica)。2　材料类别　茎尖和带腋芽的茎段。3　培养条件　 (1)启动培养基 :MS +6 BA 7.0mg·L- 1(单位下同 ) +IAA 0 .0 1+ZT 0 .1。 (2 )分化培养基和继代培养基 :MS +6 BA 3.0 +IAA 0 .0 1。上述培养基均添加 3%蔗糖、0 .5 %琼脂。 (3)生根培养基 :1/ 2MS +NAA 0 .5 ,添加 1.5 %蔗糖、0 .5 %琼脂。培养基 pH值为 5 .8,培养温度为(2 7± 2 )℃ ,光照度 2 0 0 0lx ,光照时间 12h·d- 1。4　生长与分化情况4 .1　外植体来源　以 1999年从印度及缅甸引种的含高印楝素的优良单株的幼嫩枝条上取带…     

Hepatoprotective activity of Azadirachta indica leaves on paracetamol induced hepatic damage in rats.

Effect of A. indica leaf extract on serum enzyme levels (glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, acid phosphatase and alkaline phosphatase) elevated by paracetamol in rats was studied with a view to observe any possible hepatoprotective effect of this plant. It was interesting to observe that serum enzyme levels were much elevated in paracetamol induced animals than in those receiving a combination of paracetamol and lead extract. It is stipulated that the extract treated group was protected from hepatic cell damage caused by paracetamol induction. The findings were further confirmed by histopathological study of liver.     

Neuroprotective effect of curcumin in middle cerebral artery occlusion induced focal cerebral ischemia in rats

Free radical induced neuronal damage is implicated in cerebral ischemia reperfusion (IR) injury and antioxidants are reported to have neuroprotective activity. Several in vitro and in vivo studies have proved the antioxidant potential of curcumin and its metabolites. Hence, in the present study the neuroprotective potential of curcumin was investigated in middle cerebral artery occlusion (MCAO) induced focal cerebral IR injury. 2 h of MCAO and 22 h of reperfusion resulted in the infarct volume of 210.39 +/- 31.25 mm3. Administration of curcumin 100 and 300 mg/kg, i.p. 30 min. after MCAO produced 37.23 +/- 5.10% and 46.39 +/- 10.23% (p < 0.05) reduction in infarct volume, respectively. Ischemia induced cerebral edema was reduced in a dose dependent manner. Curcumin at 300 mg/kg, i.p. produced 50.96 +/- 6.04% reduction in edema (p < 0.05) volume. Increase in lipid peroxidation after MCAO in ipsilateral and contralateral hemisphere of brain was observed, which was reduced by curcumin (300 mg/kg, i.p.)-treatment. Decrease in superoxide dismutase and glutathione peroxidase activity was observed in ipsilateral hemisphere of MCAO animal. Curcumin-treatment (300 mg/kg, i.p.) prevented IR injury mediated fall in glutathione peroxide activity. Peroxynitrite measured using rhodamine123 fluorescence and anti-nitrotyrosine immunofluorescence indicated increased peroxynitrite formation after IR insult. Curcumin-treatment reduced peroxynitrite formation and hence the extent of tyrosine nitration in the cytosolic proteins. These results suggest the neuroprotective potential of curcumin in cerebral ischemia and is mediated through its antioxidant activity.     

Effect of Bacopa monniera and Azadirachta indica on gastric ulceration and healing in experimental NIDDM rats

Gastric ulcers were induced in normal/NIDDM rats by various physical (2 hr cold restraint stress and 4 hr pylorus ligation) and chemical agents (ethanol, 1 ml/200 g, oral, 1 hr before; aspirin, 200 mg/kg, oral, 4 hr) and duodenal ulcers were induced by cysteamine (40 mg/200 g). Ulcer healing activity was studied in gastric ulcers induced by acetic acid (50%) and HCI (0.6 M). The result indicated that in both, normal and NIDDM rats, B. monniera extract (BME, 20-100 mg/kg) did not show any significant effect on blood glucose level, while A. indica (AIE, 250-1000 mg/kg) significantly decreased it. However, both BME (50 mg/kg) and AIE (500 mg/kg) showed significant anti-ulcer and ulcer-healing activities in normal and NIDDM rats. Further, the present results also indicated that the ulcer protective effects of BME was more pronounced in non-diabetic, while that of AIE was more in NIDDM rats. The anti-ulcer and ulcer-healing activities of BME and AIE may be due to their effects on various mucosal offensive and defensive factors, and correction of blood sugar level by AIE may help to have more ulcer protective effect in NIDDM rats.     

Induction of somatic embryogenesis in Azadirachta indica

A modified culture protocol has been developed for the induction of somatic embryogenesis in Azadirachta indica (neem). Embryogenic calluses were initiated from cotyledons or hypocotyls using a Murashige and Skoog (MS) agar medium supplemented with 0.5 mg l⁻¹ α-napthaleneacetic acid (NAA), 1 mg l⁻¹ 6-benzylaminopurine (BA), 1 g l⁻¹ casein hydrolysate, and 50 g l⁻¹ sucrose. The calluses, when transferred to a liquid medium similar to the agar medium but with NAA replaced by 0.5 mg l⁻¹ indole-3-acetic acid (IAA), formed globular structures which further developed a rudimentary root, after 4 to 5 weeks incubation. Subsequently, these highly differentiated tissues when transferred into a hormone-free MS medium containing 1 g l⁻¹ casein hydrolysate and 50 g l⁻¹ sucrose, active embryo masses started to appear after 1 to 2 weeks. The embryo production was found to improve more than 2 fold by adding 0.2 mg l⁻¹ zeatin to the medium. This revised version was published online in June 2006 with corrections to the Cover Date.     

Neuroprotective effect of hexasulfobutylated C60 on rats subjected to focal cerebral ischemia

The effects of hexasulfobutylated C60 (FC4S), a free radical remover, on the total volume infarct size elicited by the damaging effects of focal cerebral ischemia were studied on Long-Evans rats in vivo. FC4S was administered intravenously either 15 min before middle cerebral artery (MCA) occlusion (pretreatment groups) or it was injected when the common carotid arteries clips were removed (treatment groups). FC4S did not alter the pH, blood gases, heart rate, or mean arterial blood pressure in either pretreatment or treatment groups of the rats. However, after administration of FC4S at dosages of 10 and 100 microg/kg, the total volume of infarction was significantly reduced in both pretreatment and treatment groups. In addition, after FC4S administration, the nitric oxide (NO) content in plasma was increased and the lactate dehydrogenase (LDH) levels was decreased. It is concluded that FC4S may be used as a neuroprotective agent on focal cerebral ischemia. The beneficial effects may be partly related to its antioxidant property and to the upregulation of NO production of the compound.     

Effect of Azadirachta indica leaves on rat spermatozoa

Histochemical studies and SEM observations on the morphological changes in the head of the spermatozoa in general, and the acrosome in particular, in A. indica treated rats are reported. In the treated rats change in the shape and size of the sperm head, with a dorso-ventral constriction of the middle region of the sperm head i.e., between the anterior and posterior regions was observed. It was rather difficult to differentiate the outer acrosomal and outer plasma membranes. A decrease in the perforatorium or sub-acrosomal material, post nuclear cap and the nuclear material near the basal plate at the base of the sperm head were also observed. The results suggest that the effects are probably due to androgen deficiency and a general disturbance in carbohydrates or polysaccharides located in the sperm head, caused by the antiandrogenic property of the leaves of A. indica.     

Ultrastructural changes in cauda epididymidal epithelial cell types of Azadirachta indica leaf treated rats

To assess if cauda epididymis is a target for the effect of A. indica leaves, Wistar strain male albino rats were administered (po) A. indica leaves (100 mg/rat/day for 24 days). Transmission electron microscopic analysis revealed that in the cauda epididymal epithelium the nuclei of principal cells were enlarged and the number of coated micropinocytotic vesicles of the apical cytoplasm decreased. Microvilli were missing and mitochondrial cristae and Golgi complex were highly disrupted. The cytoplasm was abounding with lysosomal bodies. The clear cells increased in perimeter and their nuclei increased in size and contained lesser chromatin. The nuclear membrane bulged out. The cytoplasm was vacuolized. Further, there was decrease in size of the lipid droplets, mitochondria, Golgi complex, endoplasmic reticulum and there was accumulation of lysosomal bodies. The changes in the principal and clear cells appear to be due to the effect of the hypoandrogen status caused by treatment with A. indica leaves and a direct action on the epididymal epithelium.     

小檗碱对大鼠脑缺血/再灌注损伤的保护作用及免疫机制

目的:探讨小檗碱对大鼠脑缺血/再灌注损伤的保护作用及免疫机制。方法:50只SD大鼠随机分为假手术组(Sham group)、模型组(Model group)、小檗碱低剂量组(BBR-L,25 mg/kg)、小檗碱中剂量组(BBR-M,50 mg/kg)、小檗碱高剂量组(BBR-H,100 mg/kg),每组各10只。采用Longa线栓法建立脑缺血/再灌注大鼠模型,缺血2h后再灌注24 h处理。于造模成功2 h后灌胃给药,假手术组和模型组组按上述方法同体积给予生理盐水。给药24 h后,测定各组大鼠神经功能缺损程度评分及脑梗死率;采用ELISA法检测抗氧化酶SOD和GSH-Px的活性、细胞因子TNF-α、IFN-β、IL-6和NO的含量;采用流式细胞术检测CD4⁺、CD8⁺及CD4⁺/CD8⁺血清含量;进一步采用RT-qPCR与Western blot技术检测大鼠脑组织内NF-κB-NLRP3信号轴关键基因及蛋白的表达情况。结果:与假手术组比较,模型组大鼠神经功能缺损程度、脑梗死率均升高(P<0....     

Protective effect of anthocyanins in middle cerebral artery occlusion and reperfusion model of cerebral ischemia in rats

Ischemic stroke results from a transient or permanent reduction in cerebral blood flow that is restricted to the territory of a major brain artery. The major pathobiological mechanisms of ischemia/reperfusion injury include excitotoxicity, oxidative stress, inflammation, and apoptosis. In the present report, we first investigated the protective effects of anthocyanins against focal cerebral ischemic injury in rats. The pretreatment of anthocyanins (300 mg/kg, p.o.) significantly reduced the brain infarct volume and a number of TUNEL positive cells caused by middle cerebral artery occlusion and reperfusion. In the immunohistochemical observation, anthocyanins remarkably reduced a number of phospho-c-Jun N-terminal kinase (p-JNK) and p53 immunopositive cells in the infarct area. Moreover, Western blotting analysis indicated that anthocyanins suppressed the activation of JNK and up-regulation of p53. Thus, our data suggested that anthocyanins reduced neuronal damage induced by focal cerebral ischemia through blocking the JNK and p53 signaling pathway. These findings suggest that the consumption of anthocyanins may have the possibility of protective effect against neurological disorders such as brain ischemia.     

Lowering of blood sugar by water extract of Azadirachta indica and Abroma augusta in diabetes rats

Combination (1:1 ) of water extract of dried powder of root and leaves (200 mg/kg body wt) of A. augusta and A. indica respectively was administered orally to alloxan diabetic rats once a day for 8 weeks. This treatment caused significant lowering of blood sugar in fasted as estimated by glucose tolerance test. The treatment resulted in a significant reduction in serum lipids. Aqueous extract also decreased the formation of lipid peroxides estimated as thiobarbituric acid reactive substance, (TBARS), and increased antioxidants (superoxide dismutase, catalase, glutathione peroxidase and glutathione transferase) in erythrocytes. There was reduction in LPO as TBARS in heart, liver, kidney, and muscles. It also prevented decrease in body weight. Present study showed that Abroma augusta roots and A. indica leaves when given together as water extract had hypoglycaemic action and had better effect than given alone.     

Neuroprotective effect of quercetin in ectoenzymes and acetylcholinesterase activities in cerebral cortex synaptosomes of cadmium-exposed rats

This study investigated the effect of quercetin on nucleoside triphosphate diphosphohydrolase (NTPDase), 5′-nucleotidase, adenosine deaminase (ADA), and acetylcholinesterase (AChE) activities in synaptosomes from cerebral cortex of adult rats exposed to cadmium (Cd). Rats were exposed to Cd (2.5 mg/Kg) and quercetin (5, 25 or 50 mg/Kg) by gavage for 45 days. Rats were randomly divided into eight groups (n = 8–10): saline/ethanol, saline/Querc 5 mg/kg, saline/Querc 25 mg/kg, saline/Querc 50 mg/kg, Cd/ethanol, Cd/Querc 5 mg/kg, Cd/Querc 25 mg/kg, and Cd/Querc 50 mg/kg. Results demonstrated that AChE activity increased in the Cd/ethanol group when compared to saline/ethanol group. Treatment with quercetin prevented the increase in AChE activity when compared to Cd/ethanol group. Quercetin treatment prevented the cadmium-induced increase in NTPDase, 5-nucleotidase, and ADA activities in Cd/ethanol group when compared to saline/ethanol group. Our data showed that quercetin have a protector effect against Cd intoxication. This way, is a promising candidate among the flavonoids to be investigated as a therapeutic agent to attenuate neurological disorders associated with Cd intoxication.     

Neem (Azadirachta indica) cultivated in Haiti

So that valuable products from the neem tree (Azadirachta indica) will be readily available in the future, countries in the neotropics should emulate Haiti and grow the species where it thrives even in eroded, semiarid, depauperate areas suitable for few other trees.     

Identification and Antifeedant Activities of Limonoids from Azadirachta indica

Four new limonoids, azadiraindins A–D ( 1 – 4 , resp.), together with seven known analogs, were isolated from the MeOH extract of Azadirachta indica. The structures of 1 – 4 were elucidated by NMR and MS spectroscopic analyses, and the relative configuration of 1 was determined by single‐crystal X‐ray crystallography. The compounds isolated in comparatively large amount were evaluated for their antifeedant activities against Plutella xylostella; the antifeedant rate of 10 was 90.6% and the corrected mortality of 8 was 79.2%.     

An isoprenylated flavanone from leaves of Azadirachta indica

A new isoprenylated flavanone has been isolated from the leaves of Azadirachta indica and characterized as 8,3′-di-isoprenyl-5,7-dihydroxy-4′-methoxyflavanone on the basis of physical and spectroscopic evidence. This is the first report of an isoprenyl flavanone from the Meliaceae.     

Neuroprotective effect of aspirin combined with ginkgolide injection on cerebral ischemic stroke rats and its effect on ERK12 signal pathway

The main aim of this study was to evaluate the neuroprotective effect of aspirin combined with ginkgolide injection on cerebral ischemic stroke model rats and its effect on extracellular regulated protein kinase 1/2 (REK1/2) signaling pathway, and to clarify the possible mechanism of aspirin combined with ginkgolide injection on neuroprotective mechanism. Experimental rats were randomly divided into sham group, model group, aspirin group, ginkgolide group and combination group (aspirin + ginkgolide injection) (n = 20). The results revealed scores of neurological dysfunction and infarct volume in aspirin group, ginkgolide group and combination group rats were lower than those in model group (P < 0.05). Score of neurological dysfunction and the volume of cerebral infarction in combination group rats were lower than those in aspirin group and ginkgolide group (P < 0.05). Combination of aspirin and ginkgolide injection could better reduce brain water content, reduce apoptosis rate of cortical cells P < 0.05, reduce expression levels of caspase-3, Bax and p-REK1/2 proteins in ischemic brain tissue P < 0.05, and increase expression level of Bcl-2 protein than aspirin and ginkgolide injection alone P < 0.05). In conclusion, the synergistic neuroprotective effect of aspirin and ginkgolide injection on cerebral ischemic stroke rats is better than that of aspirin and ginkgolide injection alone. The mechanism of action may be that the two compounds can play a synergistic role and inhibit the activation of REK1/2 signaling pathway, thus inhibiting apoptosis of nerve cells and exerting neuroprotective effect.     

Tetracyclic triterpenoids from the leaves of Azadirachta indica

Two new tetracyclic triterpenoids zafaral [24,25,26,27-tetranorapotirucalla-(apoeupha)-6alpha-methoxy-7alpha-acetoxy-1,14-dien-3,16-dione-21-al] (1) and meliacinanhydride [24,25,26,27-tetranorapotirucalla-(apoeupha)-6alpha-hydroxy,11alpha-methoxy-7alpha,12alpha-diacetoxy,1,14,20(22)-trien-3-one] (2) have been isolated from the methanolic extract of neem leaves along with two known constituents nimocinol and isomeldenin. Their structures and the relative configurations were determined by spectroscopic methods ((1)H and (13)C NMR, IR, and MS) and 2D NMR experiments.