Neuroprotective effects of Fructus Chebulae extracts on experimental models of cerebral ischemia

OBJECTIVE： To investigate the neuroprotective ef- fects of Fructus Chebulae extract using both in vivo and invitromodels of cerebral ischemia. METHODS： As an in vitro model, oxygen glucose deprivation followed by reoxygenation（OGD-R） and hydrogen peroxide（H2 O2） induced cellular damage in rat pheochromocytoma（PC12） cells was used to investigate the neuroprotective effects of extract of Fructus Chebulae. 3-（4,5-dimethylthia- zol-2-yl）-2,5-diphenyltetrazolium bromide assay was used to calculate cell survival. For in vivo, occlu- sion of left middle cerebral artery on rats was car- ried out as a focal cerebral ischemic model. RESULTS： Fructus Chebulae extract increases the PC12 cell survival against OGD-R and H2 O2 by 68% and 91.4% respectively. Fructus Chebulae also de-creases the cerebral infarct volume by 39% and ex- tent of hemisphere swelling from 17% in control group to 10% in FructusChebulaetreated group. CONCLUSION： Fructus Chebulae, as a traditional medicine, can rescue the neuronal cell death against ischemia related damage. The possible mechanism for the neuroprotection might be the inhibition of oxidative damages occurring after acute phase of cerebral ischemia.     

Neuroprotective effect of Artemisia absinthium L. on focal ischemia and reperfusion-induced cerebral injury

Ethnopharmacological relevance

Artemisia absinthium L. has long been used as traditional herbal medicine in China, Europe and Pakistan for the treatment of gastric pain, cardiac stimulation, to improve memory and for the restoration of declining mental function.

Aim of the study

The present study was designed to investigate the potential protective effects of Artemisia absinthium on cerebral oxidative stress and damage as well as behavioral disturbances induced by cerebral ischemia and reperfusion injury in rats.

Materials and methods

Focal ischemia and reperfusion were induced by middle cerebral artery occlusion (MCAO) for 90 min, followed by 24 h reperfusion. MCAO led to significant rise in infarct size and lipid peroxidation, and depletion in glutathione content, superoxide dismutase and catalase activity in brain. Further, behavioral deficits like motor incoordination and impairment of short-term memory were also significantly impaired by MCAO as compared with sham group.

Results

The brain oxidative stress and damage, and behavioral deficits were significantly attenuated by pre-treatment with the methanol extract of Artemisia absinthium (100 mg/kg and 200 mg/kg, p.o.).

Conclusion

These findings suggested that Artemisia absinthium is neuroprotective and may prove to be useful adjunct in the treatment of stroke.     

Neuroprotective effects of Eleutherococcus senticosus bark on transient global cerebral ischemia in rats

Ethnopharmacological relevance

Eleutherococcus senticosus Maxim., classified into the family of Araliaceae, is used in a variety of diseases in traditional Korean medicine including ischemic heart disease.

Aim of the study

To determine the neuroprotective effects of Eleutherococcus senticosus on global cerebral ischemia.

Materials and methods

A four-vessel occlusion (4-VO) rat model was used to evaluate the potential protective effects against transient global cerebral ischemia ethanol extracts of Eleutherococcus senticosus was orally administered at doses of 3, 30, and 300 mg/kg twice at times of 0 and 90 min after reperfusion. The effects on memory deficit were investigated by using a Y-maze neurobehavioral test after brain ischemia, and the effects on hippocampal neuronal damage were measured 7 days after ischemia. The expressions of glial fibrillary acid protein (GFAP), CD11b antibody (OX-42), and cyclooxygenase-2 (COX-2) were investigated by immunohistochemistry.

Results

Oral administration of Eleutherococcus seticosus at 30, 100 and 300 mg/kg significantly reduced hippocampal CA1 neuronal death by 3.5%, 25.9% and 53.1%, respectively, compared with a vehicle-treated group. Oral administration of Eleutherococcus senticosus at 300 mg/kg inhibited 81.9% of the decrease in spontaneous alternation induced by 4-VOin the Y-maze test, and also attenuated ischemia-induced activation of COX-2, GFAP and OX-42 in the hippocampal CA1 region.

Conclusion

Eleutherococcus senticosus protects delayed neuronal death in the CA1 region of the hippocampus against global cerebral ischemia in rats with the recovery of spatial memory, which can be considered as the normal functioning of the hippocampus. Regarding the immunohistochemical study, the effect of Eleutherococcus senticosus may be attributable to its anti-inflammatory properties through the inhibition of COX-2 expression, microglia and astrocyte expression.     

Neuroprotective activityof Cymbopogon martinii against cerebral ischemia/reperfusion-induced oxidative stress in rats

Ethnopharmacological relevance

Cymbopogon martinii (Roxb.) Watson (Family: Graminae), commonly known as Palmarosa, is traditionally prescribed for central nervous system (CNS) disorders such as neuralgia, epileptic fits and anorexia. Although the plant possesses diverse pharmacological actions, the neuroprotective action has got little attention.

Aim of the study

The present study evaluated neuroprotective effect of essential oil of Cymbopogon martinii (EOCM) against global cerebral ischemia/reperfusion (I/R)-induced oxidative stress in rats.

Materials and methods

Global ischemic brain damage was induced by bilateral common carotid artery (BCCA) occlusion for 30 min, followed by 60 min reperfusion on Wistar albino rats. The biochemical levels of lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), total thiols and glutathione (GSH) were estimated and brain coronal sections and histopathological studies were performed.

Results

BCCA occlusion, followed by reperfusion caused varied biochemical/enzymatic alterations viz. increase in LPO and decrease in SOD, CAT, total thiols and GSH. The prior treatment of EOCM (50 mg/kg and 100 mg/kg, p.o. for 10 days) markedly reversed these changes and restored to normal levels as compared to I/R groups. Moreover, brain coronal sections and histopathological studies revealed protection against ischemic brain damage in the EOCM-treated groups.

Conclusion

This study, for the first time, shows potent neuroprotective effect of EOCM against global cerebral I/R-induced oxidative stress in rats, suggesting its therapeutic potential in cerebrovascular diseases (CVD) including stroke.     

北五味子总木脂素对脑缺血模型大鼠神经细胞凋亡及p-AKT表达的影响

目的:观察北五味子总木脂素(Schisandra chinensis lignans,SCL)对局灶性脑缺血损伤大鼠神经细胞凋亡和PI3K/AKT信号传导途径的影响,并探讨其作用机制。方法:用北五味子总木脂素高、中、低剂量组(100,50,25 mg·kg-1)给大鼠分别灌胃给药,连续14 d后,线栓法建立脑缺血损伤模型,进行神经功能评分,TTC染色观察大鼠的脑梗死面积,HE染色观察脑组织的病理形态学改变,免疫组化检测脑组织中Bcl-2和Bax的表达,Western blotting检测脑组织内p-AKT和AKT蛋白的表达情况。结果:与模型组比较,北五味子总木脂素高、中、低剂量组均能不同程度缩小脑梗死面积;改善脑组织的病理形态学改变;促进抗凋亡蛋白Bcl-2的表达,抑制促凋亡蛋白Bax表达,同时促进p-AKT的表达。结论:北五味子总木脂素对大鼠脑缺血性损伤具有一定的保护作用,机制可能与其促进p-AKT活性增加,提高脑组织抗缺血损伤的能力和抑制神经细胞的凋亡有关。     

Neuroprotective effects of water-soluble Ganoderma lucidum polysaccharides on cerebral ischemic injury in rats

Aim of the study

To investigate the neuroprotective effects of water-soluble Ganoderma lucidum polysaccharides (GLPS) on cerebral ischemic injury in rats, and to explore the involved mechanisms.

Materials and methods

Two models [middle cerebral artery occlusion (MCAO) in Sprague-Dawley (SD) rats and oxygen and glucose deprivation (OGD) in primary cultured rat cortical neurons] were employed to mimic ischemia-reperfusion (I/R) damage, in vivo and in vitro, respectively. Cerebral infarct area was measured by tetrazolium staining, and neurological functional deficits were assessed at 24 h after I/R. Neuronal apoptosis was studied by Nissl staining and DNA fragmentation assay. Neuronal injury was assessed by morphological examination using phase-contrast microscopy and quantified by measuring the amount of lactate dehydrogenase (LDH) leakage, cell viability was measured by sodium 3′-1- (phenylaminocarbonyl)-3, 4-tetrazolium-bis (4-methoxy-6-nitro) benzene sulfonic acid (XTT) reduction. Neuronal apoptosis was determined by flow cytometry, and electron microscopy was used to study morphological changes of neurons. Caspase-3, -8 and -9 activation and Bcl-2, Bax protein expression were determined by western blot analysis.

Results

Oral administration of GLPS (100, 200 and 400 mg/kg) significantly reduced cerebral infarct area, attenuated neurological functional deficits, and reduced neuronal apoptosis in ischemic cortex. In OGD model, GLSP (0.1, 1 and 10 μg/ml) effectively reduced neuronal cell death and relieved cell injury. Moreover, GLPS decreased the percentage of apoptotic neurons, relieved neuronal morphological damage, suppressed overexpression of active caspases-3, -8 and -9 and Bax, and inhibited the reduction of Bcl-2 expression.

Conclusions

Our findings indicate that GLPS protects against cerebral ischemic injury by inhibiting apoptosis by downregulating caspase-3 activation and modulating the Bcl-2/Bax ratio.     

Neuroprotective effect of Momordica charantia in global cerebral ischemia and reperfusion induced neuronal damage in diabetic mice

Ethnopharmacological relevance

Momordica charantia L. (Cucurbitaceae) fruits have been used traditionally for centuries, especially for treating diabetes and associated complications.

Aim of the study

The present study was performed to evaluate neuroprotective effect of lyophilized M. charantia fruit juice against global cerebral ischemia and reperfusion induced neuronal injury in diabetic mice.

Materials and methods

Global cerebral ischemia induced by occluding both common carotid arteries for 10 min followed by 24 h reperfusion was used to induce neuronal injury. Ischemia-reperfusion induced neuronal injury was evaluated in terms of cerebral infarct size, generation of free radicals measured as thiobarbaturic acid reactive substances (TBARS), and neurological functions measured as short term memory and motor activity.

Results

The cerebral oxidative stress and damage, and neurological deficits were dose dependently attenuated by pre-treatment with the lyophilized M. charantia juice (200-800 mg/kg, p.o., o.d.). Moreover, M. charantia also exhibited dose dependent antihyperglycemic activity in diabetic mice.

Conclusions

These results suggest that M. charantia has potent neuroprotective activity against global cerebral ischemia-reperfusion induced neuronal injury and consequent neurological deficits in diabetic mice.     

Investigation on the morphological protective effect of 5-hydroxymethylfurfural extracted from wine-processed Fructus corni on human L02 hepatocytes

Aim

To determine the mode of action of 5-hydroxymethylfurfural (5-HMF) extracted from wine-processed Fructus corni on hepatoprotective activities, the effects of 5-HMF on H₂O₂-induced human L02 hepatocytes injury was examined.

Mthods

Hepatocytes L02 injured by H₂O₂ was treated by 5-HMF. The morphological changes of the cells were observed under inverted phase-contrast, fluorescence, and transmission electron microscopy and the activities of caspase-9 and caspase-3 were tested by enzyme-linked immunosorbent detector.

Results

It revealed that 5-HMF improved the morphology of H₂O₂-treated human L02 hepatocytes, and also inhibited the level of caspase-9 and caspase-3 of them.

Conclusions

These results suggested a morphological hepatocyte protective effect and the anti-apoptosis mechanism by 5-HMF.     

Bioevaluation of Anisomeles indica extracts and their inhibitory effects on Helicobacter pylori-mediated inflammation

Ethnopharmacological relevance

Helicobacter pylori is associated with the majority of gastric disorders and the antibiotic resistant rates have increased annually worldwide. Anisomeles indica and its constituent, ovatodiolide (OVT), were shown to have bactericide activity against Helicobacter pylori. The aim of this study was to manufacture extracts containing the effective constituent, OVT, and evaluate their bactericidal function and the inhibition of inflammatory responses to Helicobacter pylori infection.

Materials and methods

Various concentrations of ethanol for extraction of Anisomeles indica were performed and the content of OVT was analyzed by high-performance liquid chromatography (HPLC). The anti-bacterial activity of Anisomeles indica ethanol extracts and the constituent OVT were determined. Additional experiments were performed to investigate the Anisomeles indica ethanol extracts and OVT to inhibit the Helicobacter pylori-induced inflammation of both gastric epithelial cells and macrophages.

Results

Amongst the extracts tested, 50% and 95% ethanol extracts contained large amount of OVT and showed potent anti-Helicobacter pylori activity. An in vitro Helicobacter pylori-infection model revealed that 95% ethanol extract attenuated Helicobacter pylori-induced nuclear factor kappa B (NF-κB) activity and interleukin (IL)-8 secretion of gastric epithelial cells. In addition, 95% ethanol extract significantly inhibited lipopolysaccharide (LPS)-induced expression of inducible nitric oxide synthase (iNOS), as well as production of nitric oxide (NO) and tumor necrosis factor α (TNF-α) by macrophages.

Conclusions

This study reveals that Anisomeles indica ethanol extracts containing OVT may be a potent and economic therapeutic agent for Helicobacter pylori infection and attenuation of Helicobacter pylori-mediated inflammation.     

Neuroprotective activity of Matricaria recutita Linn against global model of ischemia in rats

Ethnopharmacological relevance

Traditionally, the whole plant is used for various diseases, including neuronal disorders.

Aim of the study

To evaluate the neuroprotective effect of Matricaria recutita L. against global cerebral ischemia/reperfusion (I/R) injury-induced oxidative stress in rats.

Materials and methods

Neuroprotective activity was carried out by global cerebral ischemia on Sprague–Dawley rats by bilateral carotid artery (BCA) occlusion for 30 min followed by 60 min reperfusion. The antioxidant enzymatic and non-enzymatic levels were estimated along with cerebral infarction area and histopathological studies.

Results

The Matricaria recutita L. methanolic extract showed dose-dependent neuroprotective activity by significant decrease in lipid peroxidation (LPO) and increase in the superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and total thiol levels in extract treated groups as compared to ischemia/reperfusion group. Cerebral infarction area was significantly reduced in extract treated groups as compared to ischemia/reperfusion group.

Conclusion

The methanolic extract of Matricaria recutita L. showed potent neuroprotective activity against global cerebral ischemia/reperfusion injury-induced oxidative stress in rats.     

藤梨根正丁醇提取物和总黄酮苷抗肿瘤作用研究

目的:观察藤梨根正丁醇提取物和总黄酮苷对体内外肿瘤的抑制作用。方法:建立小鼠S180肉瘤和H22肝癌模型,分别将72只接种小鼠随机分为对照组、受试药高、中、低剂量组与阳性对照(环磷酰胺)组,观察藤梨根正丁醇提取物和总黄酮苷对体内肿瘤生长的抑制作用以及脾脏、胸腺指数、肿瘤坏死因子的影响。MTT法观察藤梨根正丁醇提取物不同浓度和不同时间对体外人肺腺癌细胞株A549细胞生长的抑制作用。流式细胞仪检测藤梨根正丁醇提取物不同浓度对人肺腺癌细胞株A549细胞周期的影响。结果:藤梨根总黄酮苷对S180肉瘤和H22肝癌模型,中剂量组可以减轻瘤重,抑瘤率分别为33.32%,34.62%;体外实验表明藤梨根正丁醇提取物对A549肺癌细胞有抑制作用,作用持续时间48 h;藤梨根正丁醇提取物1.25,0.625 g.L-1可使G0~G1期出现阻滞,显著减少S期细胞比例。结论:藤梨根正丁醇和总黄酮苷均有抗肿瘤作用。     

丹参红花注射液对实验性大鼠脑缺血的保护作用

目的:观察丹参红花注射液(丹参、西红花等)对实验性大鼠脑缺血的保护作用.方法:采用结扎大鼠双侧颈总动脉方法复制急性实验性不完全性脑缺血模型,观察丹参红花注射液对大鼠脑指数、脑含水量、脑血管通透性及脑组织形态学的影响.结果:丹参红花注射液(7.2,14.4mg·kg-1)能明显减轻大鼠急性脑缺血所引起的脑指数、脑含水量的病理变化.同时降低脑内毛细血管通透性,维持脑组织神经细胞形态结构的正常.结论:丹参红花注射液有明显的脑缺血保护作用.     

Acanthopanax senticosus extracts have a protective effect on Drosophila gut immunity

Ethnopharmacological relevance

Aanthopanax senticosus (A. senticosus) Harms is a classical adaptogenic agent used in China. It has been applied as an analeptic aid to improve weakened physical status. However, little is known about the effects of A. senticosus on inflammatory disease processes.

Materials and methods

Flies fed with standard cornmeal–yeast medium were used as controls, and the treatment groups contained 10% of A. senticosus aqueous extracts (root or fruit) in standard medium. Survival rate was performed by feeding a vial containing five layers of filter paper hydrated with 5% sucrose solution contaminated with pathogenic or toxic compounds. Imaging of the guts was viewed under the microscope. Death cells were detected by 7-AAD staining.

Results

The A. senticosus extract improved the survival rate, attenuated the death of intestinal epithelial cells, promoted the expression of antimicrobial peptide genes, and decreased the formation of melanotic masses. Moreover, our results indicated that the protective effect of fruit is much higher than that of root extracts.

Conclusions

A. senticosus extracts have a protective effect on Drosophila gut immunity and stress response, and may contribute to the prevention of inflammatory diseases induced by pathogenic and toxic compounds.     

Evaluation of the anti-myocardial ischemia effect of individual and combined extracts of Panax notoginseng and Carthamus tinctorius in rats

Ethnopharmacological relevance

The decoction of combined Panax notoginseng (Burk) F.H. Chen and Carthamus tinctorius L. has a history of use in traditional medicine for the prevention and treatment of cardiovascular diseases such as angina pectoris and myocardial infarction.

Aim of the study

In this study, we investigated the effects of individual herbal extracts and combined extracts on anti-myocardial ischemia injuries in vivo, and determined the proper dosage of Panax notoginseng (EPN) combined with Carthamus tinctorius (ECT) that could strengthen their cardio-protective effects. Meanwhile, their potential anti-oxidative stress and anti-inflammation effect were assessed.

Material and Methods

SD rats were orally given individual EPN 50, 100 mg/kg, ECT 100, 200 mg/kg, and different combinations between them. Myocardial infarction was produced by occlusion of the left anterior descending coronary artery for 24 h. Infarct area was determined with 2,3,5-triphenyltetrazolium chloride (TTC) staining. The biomarkers related to myocardial ischemia injury were determined. Simultaneously, hemodynamic parameters were monitored as left ventricular systolic pressure (LVSP), LV end-diastolic pressure (LVEDP) and maximal rate of increase and decrease of left ventricular pressure (dP/dt_max). The oxidative stress indicators and inflammatory factors were also evaluated.

Results

The results showed EPN or ECT significantly reduced infarct size, improved cardiac function, decreased levels of creatine kinase (CK) and lactate dehydrogenase (LDH) (all P<0.05 vs. control ). EPN or ECT alone also restrained the oxidative stress related to myocardial ischemia injury as evidenced by decreased malondialdehyde (MDA) and elevated superoxide dismutase (SOD) activity (all P<0.05 vs. control). However, this cardio-protective effect was further strengthened by their combinations. Among all the combinations, EPN 50 mg/kg plus ECT 200 mg/kg showed predominant potential to reduce infarct size (22.21±1.72%, P<0.05 vs. each single, respectively), preserve cardiac function (P<0.05 vs. ECT 200 mg/kg for LVEDP and −dP/dt_max) after myocardial ischemia injury in rats. This heart protection was confirmed with the lowered cardiac troponin I (cTnI) (P<0.05 vs. ECT 200 mg/kg and EPN 50 mg/kg, respectively). Oxidative stress and inflammation are the two key factors in the pathogenesis of myocardial ischemia injury. In the present study, EPN 50 mg/kg plus ECT 200 mg/kg markedly increased SOD and GSH-Px activity (475.30±23.60 U/ml, P<0.05 vs. each single, respectively), while elevated MDA level was significantly depressed. Meanwhile, the inflammatory cascade was inhibited as evidenced by decreased cytokines such as tumor necrosis factor-α (TNF-α), C-reactive protein (CRP) and interleukin-1β (IL-1β).

Conclusion

These results demonstrated EPN, ECT and their combinations exhibited significant cardio-protective effects. The findings suggest EPN combined with ECT may be therapeutically more useful for ameliorating anti-myocardial ischemia injuries than individual herbal extract, and EPN 50 mg/kg plus ECT 200 mg/kg is the appropriate combination in the present research. The cardio-protective effect of this combination was achieved partially by decreasing oxidative stress and repressing inflammatory cascade.     

中药及其提取物对脑缺血保护作用的实验研究进展

综述了近10年来中药及其提取物对脑缺血保护作用的实验研究。将已报道的中药按其来源分为植物药、动物药和矿物药共3大类,分别列举了其有效成分或提取物、及其制剂治疗脑缺血的现状。     

Gastroprotective activity of Cenostigma macrophyllum Tul. var. acuminata Teles Freire leaves on experimental ulcer models

Ethnopharmacological relevance

Cenostigma macrophyllum Tul. var. acuminata Teles Freire (Leguminosae-Caesalpinioideae), popularly known in Brazil as “caneleiro”, is widely used in folk medicine against gastrointestinal diseases. In previous studies, the ethanol extract of leaves from Cenostigma macrophyllum Tul. var. acuminata Teles Freire had shown antinociceptive, anti-inflammatory, antibacterial, antioxidant and antiulcerogenic activities.

Aim of the study

The aim of this study was to assess the gastroprotective effect of the hydroalcoholic fraction of leaves of Cenostigma macrophyllum Tul. var. acuminata Teles Freire (Cm-FHA), as well as to elucidate the possible underlying mechanisms of action.

Materials and methods

Mice were used for the evaluation of the acute toxicity, and mice and rats to study the gastroprotective activity. The potential gastroprotective of Cm-FHA was assessed on different gastric ulcer models in rodents, such as absolute ethanol, HCl/ethanol, ischemia-reperfusion, cold restraint stress and indomethacin. The participation of prostaglandins, NO-synthase pathway and ATP-sensitive potassium channels (K_ATP) in gastroprotective activity of Cm-FHA were evaluated after treatment with a cyclooxygenase inhibitor (indomethacin), a NO-synthase inhibitor (L-NAME) and a K_ATP channel blocker (glibenclamide 5 mg/kg), respectively. Likewise, the catalase activity was determinated in order to assess the possible participation of antioxidant mechanisms.

Results

No signs of acute toxicity was observed after oral acute administration of Cm-FHA, considering the analyzed parameters. Likewise, Cm-FHA promoted a protective effect against gastric ulcers induced by absolute ethanol (lesion inhibition by 40% at both 100 and 200 mg/kg), HCl/ethanol (lesion inhibition by 50 or 48% at 100 or 200 mg/kg, respectively), ischemia-reperfusion (lesion inhibition by 49 or 90% at 100 or 200 mg/kg, respectively) and cold restraint stress (lesion inhibition by 63 or 76% at 100 or 200 mg/kg, respectively), as well as a increase of catalase activity was observed. Otherwise, Cm-FHA was not able to protect gastric mucosa against indomethacin-induced lesions. Nitric oxide release, the of K_ATP channels opening and antioxidant activity are the possibly involved in the Cm-FHA-induced gastroprotective activity.

Conclusion

This study corroborates the folk medicine use of Cenostigma macrophyllum for treatment of gastric ulcers, as well as reinforces this species as a valuable source of promising natural drugs with gastroprotective activity.     

Analgesic and anti-inflammatory effects of Cassia siamea Lam. stem bark extracts

Aim of the study

The present study was carried out to investigate analgesic and anti-inflammatory activities of Cassia siamea Lam stem bark extracts. We have also determined the cytotoxicity of each extract.

Materials and methods

C. siamea, a widespread medicinal plant traditionally used in sub-Saharan Africa, was collected in Congo Brazzaville. Stem bark was extracted with petroleum ether (CSE1), chloroform (CSE2), ethanol (CSE3) and water (CSE4). Analgesic, anti-inflammatory and antipyretic activities of these extracts were assessed in rats with hot plate test, paw pressure and carrageenan induced paw oedema. Cytotoxicity was assessed against KB and Vero cells.

Results

At the doses used (100, 200, and 400 mg/kg) ethanol and water extracts showed significant and dose-dependent analgesic and anti-inflammatory effects. None of the extracts had cytotoxic activity on KB and Vero cell lines and the most active extracts (CSE3 and CSE4) had no acute toxicity.

Conclusions

The study highlighted the analgesic and anti-inflammatory of C. siamea stem bark. Four major families of compounds present in the plant may explain these activities: triterpenes (lupeol, oleanolic acid, ursolic acid, friedelin, betulin), flavonoids (apigenin, kaempferol, luteolin), anthraquinones (emodin), phytosterols (stigmasterol, beta-sitosterol).     

Neuroprotective effects of a standardized flavonoid extract from Diospyros kaki leaves

Ethnopharmacological relevance

Flavonoids, extracted from the leaves of Diospyros kaki, are the main therapeutic components of NaoXingQing (NXQ), a potent and patented Chinese herbal remedy widely used in China for the treatment of apoplexy syndrome.

Aim of the study

To investigate the neuroprotective effects of FLDK-P70, a standardized flavonoid extract, using in vivo rat models of both focal ischemia/reperfusion (I/R) injury induced by middle cerebral artery occlusion (MCAO) and on transient global brain ischemia induced by four-vessel occlusion (4-VO). We also aim to examine the effects of FLDK-P70 on glutamate-induced cell injury of hippocampal neurons as well as on hypoxia-induced injury of cortical neurons in primary cell culture.

Materials and methods and results

Administration of FLDK-P70 for 12 days (40, 80 mg/kg body weight, p.o., 5 days before and 7 days after 4-VO) increased the survival of hippocampal CA1 pyramidal neurons after transient global brain ischemia. Similarly, administration of FLDK-P70 for 7 days (40, 80 mg/kg body weight, p.o., 3 days before and 4 days after MCAO) significantly reduced the lesion of the insulted brain hemisphere and improved the neurological behavior of rats. In primary rat hippocampal neuronal cultures, pretreatment with FLDK-P70 (5, 10 μg/ml) protected neurons from glutamate-induced excitotoxic neuronal death in a dose-dependent manner. In primary rat cerebral cortical neuronal culture, pretreatment with FLDK-P70 (25, 100 μg/ml) also reduced hypoxia–reoxygen induced neuronal death and apoptosis in a dose-dependent manner.

Conclusions

These in vivo and in vitro results suggest that FLDK-P70 significantly protects rats from MCAO and 4-VO ischemic injury in vivo and protects hippocampal neurons from glutamate-induced excitotoxic injury as well as cortical neurons from hypoxia-induced injury in vitro. The mechanisms of these effects may be due to the antioxidative activity of the flavonoids. These results convincingly demonstrate that FLDK-P70 may be useful for the prevention and treatment of ischemia/reperfusion injury and other related neurodegenerative diseases.