An-Gong-Niu-Huang Wan protects against cerebral ischemia induced apoptosis in rats: Up-regulation of Bcl-2 and down-regulation of Bax and caspase-3

Ethnopharmacological relevance

The An-Gong-Niu-Huang Wan (AGNH), a Chinese traditional medicine, has been used for treatment of cerebral diseases for centuries in China and other Asian countries, and is approved by the State Food and Drug Administration of China for the treatment of stroke. The aim of present study is to test the neuroprotective effects of AGNH on cerebral ischemia in rats and to explore the underlying mechanisms.

Materials and methods

75 Male Sprague-Dawley rats were randomly divided into 5 groups: sham, ischemia–reperfusion (I/R), and I/R plus 0.065 g/kg/d AGNH, 0.125 g/kg/d AGNH and 0.25 g/kg/d AGNH. Cerebral ischemia was induced by 1.5 h of middle cerebral artery occlusion (MCAO). Neurological functional deficits were evaluated according to Zea longa?s score, cerebral infarct area was measured by tetrazolium staining. Cell injury and apoptosis were assessed by Nissl staining and DNA fragmentation assay. The expression of Bax, Bcl-2 and caspase-3 were analyzed by Western blot.

Results

Rats subjected to MCAO exhibited worsened neurological score, infarct area, cell damage and apoptosis. These were all attenuated by AGNH (0.125 and 0.25 g/kg/d). Moreover, AGNH reversed cerebral ischemia induced decreases in Bcl-2 expression and increases in Bax and caspase-3 expression.

Conclusions

These results suggest that AGNH exerts neuroprotective effects, and the neuroprotection is likely to relate to depressed Bax/Bcl-2 ratio and caspase-3 level, leading to inhibition of apoptotic cell death.     

Neuroprotective effect of calycosin on cerebral ischemia and reperfusion injury in rats

Ethnopharmacological relevance

Radix Astragali has been commonly used as traditional herbal medicine in China for reinforcing vital energy, strengthening superficial resistance and promoting the discharge of pus and the growth of new tissue.

Aim of the study

The present study was to investigate the neuroprotective effect of calycosin isolated from the roots of Radix Astragali on cerebral ischemic/reperfusion injury.

Materials and methods

After 24 h of reperfusion following ischemia for 2 h induced by middle cerebral artery occlusion (MCAO), Sprague-Dawley rats were intragastrically administered different doses of calycosin (7.5, 15, 30 mg/kg, respectively). Neurological deficit, infarct volume, histopathology changes and some oxidative stress markers were evaluated after 24 h of reperfusion.

Results

Treatment with calycosin significantly ameliorated neurologic deficit and infarct volume after cerebral ischemia reperfusion. Calycosin also reduced the content of malondialdehyde (MDA), protein carbonyl and reactive oxygen species (ROS), and up-regulated the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in a dose-dependent manner. Moreover, calycosin can also inhibit the expression of 4-Hydroxy-2-nonenal (4-HNE).

Conclusion

These results suggest that calycosin has a neuroprotective effect against cerebral ischemia/reperfusion injury. The mechanism might be attributed to its antioxidant effects.     

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.     

Protective effect of hydroalcoholic extract of Mimusops elengi Linn. flowers against middle cerebral artery occlusion induced brain injury in rats

Ethnopharmacological relevance

In the traditional Indian and Thai system of medicine, Mimusops elengi Linn., flower is used as brain tonic and to calm anxiety and panic attacks.

Aim of the study

The present study was designed to investigate the neuroprotective effect of hydroalcoholic extract of Mimusops elengi (ME) against cerebral ischemic reperfusion injury in rats.

Materials and methods

Male rats were pretreated with ME (100 and 200 mg/kg) for seven days and focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) method. After 60 min of MCAO and 24 h of reperfusion, a battery of behavioral tests assessed the extent of neurological deficits. Infarct volume and brain edema were measured in TTC stained brain sections and the extent of blood brain barrier (BBB) disruption was observed by Evan's blue extravasation. Oxidative and nitrative stress parameters were estimated in the brain homogenates. Further, simultaneous quantification of five polyphenolic biomarkers were done using HPLC.

Results

Pretreatment with ME at doses of 100 and 200 mg/kg significantly improved the neurobehavioral alterations and reduced the infarct volume, edema and extent of BBB disruption induced by ischemia reperfusion injury. It also prevented the alteration in the antioxidant status and reduced the nitrite levels when compared to ischemic animals. Further, HPLC studies revealed that ME contains five bioactive polyphenolic compounds.

Conclusions

These results clearly indicate the neuroprotective effect of ME against stroke like injury. The observed protective effect might be attributed to the polyphenolic compounds and their antioxidant and anti-inflammatory property.     

Total saponins of Panax Notoginseng modulate the expression of caspases and attenuate apoptosis in rats following focal cerebral ischemia-reperfusion

Ethnopharmacological relevance

Total saponins of Panax notoginseng (TSPN), main constituents extracted from Panax Notoginseng, a highly valued traditional Chinese medicine, have been shown to be an effective agent on cerebral infarction.

Aim of the study

The effects of TSPN on apoptosis and expressions of caspase-1, caspase-3 and caspase-8 were studied after cerebral ischemia for 2 h followed by reperfusion for 46 h in rats.

Materials and methods

Rats were subjected to transient middle cerebral artery occlusion (MCAO) model using the intraluminal thread. TSPN was administered intraperitoneally at 5 min before and 12 h, 24 h and 36 h after MCAO, respectively.

Results

TSPN (at the dose of 25 mg/kg) significantly attenuated TUNEL-positive cells and reduced the expression of caspase-1 and caspase-3 compared to the model group, while it had no obvious effect on the expression of caspase-8.

Conclusions

The neuroprotective effect of TSPN on focal ischemia may be related to inhibition of apoptosis and caspases activation.     

n-Butanol soluble fraction of the water extract of Chinese toon fruit ameliorated focal brain ischemic insult in rats via inhibition of oxidative stress and inflammation

Aim of the study

Toona sinensis Roem. (Meliaceae; Toona sinensis; Chinese toon) is a type of arbor that is widely distributed in Asia. The fruits of Toona sinensis Roem has been traditionally recognized for treatment of cerebrovascular diseases. To evaluate the potential clinical use of the fruits of Toona sinensis Roem, we determined the dose dependence of the neuroprotective efficacy in a focal cerebral ischemic reperfusion model of rats and explored the underlying mechanisms.

Materials and methods

Rats were subjected to occlusion of the middle cerebral artery (MCAO) by a nylon filament and treated with different doses (20 mg/kg and 30 mg/kg) of n-butanol soluble fraction of the water extract of Chinese toon fruit or the vehicle for 1 week before induction of ischemia, s.i.d..

Results

n-Butanol soluble fraction of the water extract of Chinese toon fruit reduced in a dose-dependent manner the ischemia-induced cerebral infarct and edema volume and attenuated neurological deficits observed at 6 h point after ischemia. n-Butanol soluble fraction of the water extract of Chinese toon fruit reduced the levels of nitrate, nitrite, lipid peroxidation, cyclooxygenase-1, thromboxane in post-ischemic brain. n-Butanol soluble fraction of the water extract of Chinese toon fruit adjusted the elevation of the activity of glutathione peroxidase and superoxide dismutase in ischemic brain.

Conclusions

The present study was the first evidence of effectiveness of n-butanol soluble fraction of the water extract of Chinese toon fruit in the rat stroke models, as it reduced infarct volume, inhibited the oxidative stress and inflammation.     

Protective effect of Ilex latifolia, a major component of "kudingcha", against transient focal ischemia-induced neuronal damage in rats

Aims of the study

Ilex latifolia (Aquifoliaceae), a primary component of “kudingcha”, has been used in Chinese folk medicine to treat various kinds of diseases including headaches, inflammatory diseases, and cardiac ischemic injury. The present study investigated the protective effect of the ethanol extract of Ilex latifolia against transient, focal, ischemia-induced neuronal damage.

Materials and methods

Transient focal ischemia was induced by 2 h middle cerebral artery occlusion followed by 24 h reperfusion (MCAO/reperfusion) in rats. After MCAO/reperfusion, brain infarction and neuronal death were measured by triphenyltetrazolium chloride and hematoxylin and eosin staining, respectively. Glutathione concentration and lipid peroxidation rate were measured. The expression levels of phosphorylated mitogen activated proteins kinases (MAPKs), cyclooxygenase 2 (COX-2), and anti-apoptotic and pro-apoptotic proteins were detected by Western blot.

Results

Ilex latifolia (50-200 mg/kg) significantly reduced MCAO/reperfusion-induced infarction and edema formation, neurological deficits, and brain cell death. Depletion of glutathione level and lipid peroxidation induced by MCAO/reperfusion were inhibited by administration of Ilex latifolia. The increase of phosphorylated MAPKs, COX-2, and proapoptotic proteins and the decrease of antiapoptotic protein in MCAO/reperfusion rats were significantly inhibited by treatment with Ilex latifolia.

Conclusion

Ilex latifolia ameliorated ischemic injury induced by MCAO/reperfusion in rats, and this neuroprotective effect might be associated with its anti-apoptotic effect, resulting from anti-oxidative and anti-inflammatory actions.     

Calycosin-7-O-β-d-glucoside regulates nitric oxide /caveolin-1/matrix metalloproteinases pathway and protects blood–brain barrier integrity in experimental cerebral ischemia–reperfusion injury

Ethnopharmacology relevance

Astragali Radix (AR) has been used for thousands years to treat ischemic stroke. Calycosin and its glycoside form calycosin-7-O-β-d-glucoside (CG) are two representative isoflavones in Astragali Radix. However, its neurological effects and related molecular mechanisms are largely unknown. The present study aims to evaluate the neuroprotective effects of CG on blood–brain barrier (BBB) integrity of ischemic brain tissue and explore the relevant signaling mechanisms.

Material and method

Male adult Sprague-Daweley rats were subjected to 2 h of middle cerebral artery occlusion (MCAO) plus 24 h or 14 days of reperfusion. CG (26.8 mg/kg) was intraperitoneally administered into the rats at 15 min before onset of ischemia. The neuroprotective effects of CG were evaluated by measuring infarct volume, histological damage and BBB permeability. Furthermore, the effects of CG on scavenging nitric oxide (NO), and modulating matrix metalloproteinases (MMPs) and caveolin-1 (cav-1) were investigated with in vitro cultured brain microvascular endothelial cells treated with NO donor or oxygen–glucose deprivation (OGD) and/or in vivo rat model of MCAO cerebral ischemia–reperfusion injury.

Results

CG treatment significantly reduced infarct volume, histological damage and BBB permeability in the in vivo MCAO ischemia–reperfusion rat model. CG treatment remarkably inhibited the expression and activities of MMPs, and secured the expression of cav-1 and tight junction proteins in the microvessels isolated from ischemic rat cortex. Furthermore, CG was revealed to scavenge NO, inhibit the activities of MMP-2 and MMP-9, and attenuate cell death in the in vitro cultured brain microvascular endothelial cells under OGD condition.

Conclusion

CG could protect BBB integrity in experimental cerebral ischemia–reperfusion injury via regulating NO/cav-1/MMPs pathway.     

Effect of plants used in Mexico to treat gastrointestinal disorders on charcoal–gum acacia-induced hyperperistalsis in rats

Ethnopharmacological relevance

A total of 28 plant extracts, belonging to 26 different plant species are commonly used in Traditional Mexican Medicine for the treatment of gastrointestinal disorders such as diarrhea.

Aim of the study

To evaluate the effect of medicinal plant extracts on induced hyperperistalsis in rats.

Materials and methods

Charcoal meal test was used in this study. Extracts were tested at a dose of 300 mg/kg.

Results

From all the plant extracts tested, only Geranium mexicanum (roots) showed 100% of inhibition. The extracts of Artemisia absinthium, Matricaria recutita, Caesalpinia pulcherrima, Lygodium venustum, Chenopodium ambrosoides (green variety), Aloysia triphylla, Artemisia ludoviciana, Chiranthodendron pentadactylon, and Cocos nucifera showed moderate inhibitory activity with values ranging from 30 to 57%. Their activities were greater than that of or equal to loperamide (34% of inhibition at doses of 10 mg/kg) drug used as control. The remaining plants exhibited marginal or null inhibitory effect on hyperpropulsive movement of the small intestine.

Conclusions

The results obtained in this study give some scientific support to the popular use of 23 of the plants tested for the treatment of gastrointestinal disorders such as diarrhea in Mexican traditional medicine. However, roots of Geranium mexicanum should be used in herbal medicine with care to avoid toxicity.     

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.     

Cerebralcare Granule,a Chinese herb compound preparation,improves cerebral microcirculatory disorder and hippocampal CA1 neuron injury in gerbils after ischemia–reperfusion

Aim of the study

Cerebralcare Granule^® (CG) is a Chinese herb compound preparation that has been used for treatment of cerebrovascular related diseases. However, the effect of post-treatment with CG on ischemia and reperfusion (I/R) induced cerebral injury is so far unclear.

Materials and methods

In present study, cerebral global I/R was induced in Mongolian gerbils by clamping bilateral carotid arteries for 30 min followed by reperfusion for 5 days, and CG (0.4 g/kg or 0.8 g/kg) was administrated 3 h after the initiation of reperfusion.

Results

Post-treatment with CG for 5 days attenuated the I/R-induced production of hydrogen peroxide in, leukocyte adhesion to, and albumin leakage from cerebral microvessels, and, meanwhile, protected neuron from death, reduced the number of caspase-3- and Bax-positive cells, and increased Bcl-2-positive cells in hippocampal CA1 region.

Conclusion

The results suggest that CG given after initiation of reperfusion is able to ameliorate cerebral microvascular dysfunction and hippocampal CA1 neuron damage caused by I/R.     

Evaluation of antidiabetic and antihyperlipidemic activity of Artemisia indica linn (aeriel parts) in Streptozotocin induced diabetic rats

Ethnopharmacological relevance

Diabetes mellitus is a major metabolic disorder affecting a huge population all over the world. Artemisia species have been extensively used for the management of diabetes in folkloric medicine. The present study is designed to investigate the antidiabetic and antihyperlipidemic effects of aeriel parts of Artemisia indica.

Materials and methods

Hydromethanolic crude extracts, chloroform, ethyl acetate and n-butanol fractions of aerial parts of Artemisia indica were tested for their antidiabetic potential in Streptozotocin (STZ) (50 mg/kg, i.p.) induced diabetic Sprague-Dawley rats. Blood glucose level, body weight, serum lipid profile and activities of liver enzymes were determined. The extracts were further subjected to preliminary phytochemical analysis.

Results

A daily oral dose of hydromethanolic crude extracts (200 and 400 mg/kg b.w.) and chloroform fraction (200 mg/kg b.w.) of Artemisia indica for 15 days showed a significant reduction in blood glucose level which was comparable to that of the standard antidiabetic drug, glibenclamide (500 μg/kg, p.o.). Artemisia indica extracts also showed reduction in total cholesterol, triglycerides and low density lipoproteins as well as serum creatinine level, serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT) and alkaline phosphatase (ALP) in diabetic rats.

Conclusion

According to the results Artemisia indica possesses hypoglycemic, antihyperlipidemic and valuable effects on liver and renal functions in diabetic rats, which seems to validate its traditional usage.     

Therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemia/reperfusion injury in rats

Ethnopharmacological relevance

Breviscapine injection is a Chinese herbal medicine standardized product extracted from Erigeron breviscapus (Vant.) Hand.-Mazz. It has been widely used for treating cardiovascular and cerebrovascular diseases. However, the therapeutic time window and the action mechanism of breviscapine are still unclear. The present study was designed to investigate the therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemic/reperfusion injury.

Materials and methods

Sprague–Dawley rats were subjected to middle cerebral artery occlusion for 2 h followed by 24 h of reperfusion. Experiment part 1 was used to investigate the therapeutic time window of breviscapine. Rats were injected intravenously with 50 mg/kg breviscapine at different time-points of reperfusion. After 24 h of reperfusion, neurologic score, infarct volume, brain water content and serum level of neuron specific enolase (NSE) were measured in a masked fashion. Part 2 was used to explore the therapeutic mechanism of breviscapine. 4-Hydroxy-2-nonenal (4-HNE), 8-hydroxyl-2′- deoxyguanosine (8-OHdG) and the antioxidant capacity of ischemia cortex were measured by ELISA and ferric-reducing antioxidant power (FRAP) assay, respectively. Immunofluorescence and western blot analysis were used to analyze the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1).

Results

Part 1: breviscapine injection significantly ameliorated neurologic deficit, reduced infarct volume and water content, and suppressed the levels of NSE in a time-dependent manner. Part 2: breviscapine inhibited the increased levels of 4-HNE and 8-OHdG, and enhanced the antioxidant capacity of cortex tissue. Moreover, breviscapine obviously raised the expression of Nrf2 and HO-1 proteins after 24 h of reperfusion.

Conclusion

The therapeutic time window of breviscapine injection for cerebral ischemia/reperfusion injury seemed to be within 5 h after reperfusion. By up-regulating the expression of Nrf2/HO-1 pathway might be involved in the therapeutic mechanism of breviscapine injection.     

Bitter tastants alter gastric-phase postprandial haemodynamics

Ethnopharmacological relevance

Since Greco-Roman times bitter tastants have been used in Europe to treat digestive disorders, yet no pharmacological mechanism has been identified which can account for this practice. This study investigates whether the bitter tastants, gentian root (Gentian lutea L.) and wormwood herb (Artemisia absinthium L.), stimulate cephalic and/or gut receptors to alter postprandial haemodynamics during the gastric-phase of digestion.

Materials and methods

Normal participants ingested (1) 100 mL water plus capsules containing either cellulose (placebo-control) or 1000 mg of each tastant (n=14); or (2) 100 mL of water flavoured with 500 or 1500 mg of each tastant (a) gentian (n=12) and (b) wormwood (n=12). A single beat-to-beat cardiovascular recording was obtained for the entire session. Pre/post-ingestion contrasts with the control were analysed for (1) the encapsulated tastants, in the “10 to 15” minute post-ingestion period, and (2) the flavoured water in the “5 to 10” minute post-ingestion period.

Results

Water, the placebo-control, increased cardiac contraction force and blood pressure notwithstanding heart rate decreases. Encapsulated tastants did not further alter postprandial haemodynamics. In contrast gentian (500 and 1500 mg) and wormwood (1500 mg) flavoured water elicited increased peripheral vascular resistance and decreased cardiac output, primarily by reducing stroke volume rather than heart rate.

Conclusions

Drinking 100 mL water elicits a pressor effect during the gastric-phase of digestion due to increased cardiac contraction force. The addition of bitter tastants to water elicits an additional and parallel pressor effect due to increased peripheral vascular resistance; yet the extent of the post-prandial blood pressure increases are unchanged, presumably due to baroreflex buffering. The vascular response elicited by bitter tastants can be categorised as a sympathetically-mediated cephalic-phase response. A possible mechanism by which bitter tastants could positively influence digestion is altering gastric-phase postprandial haemodynamics and supporting postprandial hyperaemia.     

Artemisia copa aqueous extract as vasorelaxant and hypotensive agent

Ethnopharmacological relevance

Artemisia copa Phil. (Asteraceae) is a medicinal plant commonly used in traditional medicine in Argentina.

Aim of the study

The vasorelaxant and hypotensive activities of the aqueous extract of Artemisia copa have been investigated.

Materials and methods

The in vitro effect of the extract and isolated compounds from Artemisia copa was investigated using isolated rat aortic rings. The acute effect caused by the intravenous (i.v.) infusion (0.1–300 mg/kg) on blood pressure and heart rate was evaluated in spontaneous hypertensive rats. In addition, a phytochemical analysis of the extract was performed by HPLC.

Results

Artemisia copa had a relaxant effect in endothelium-intact aortic rings that had been pre-contracted with 10⁻⁷ M phenylephrine (E_max=96.7±1.3%, EC₅₀=1.1 mg/ml), 10⁻⁵ M 5-hydroxytriptamine (E_max=96.7±3.5%, EC₅₀=1.5 mg/ml) and 80 mM KCl (E_max=97.9± 4.4%, EC₅₀=1.6 mg/ml). In denuded aortic rings contracted by phenylephrine, a similar pattern was observed (E_max=92.7±6.5%, EC₅₀=1.8 mg/ml). l-NAME, indomethacin, tetraethylammonium and glibenclamide were not able to block the relaxation induced by the extract. Nevertheless, the pre-treatment with Artemisia copa attenuated the CaCl₂-induced contraction in a concentration-dependent manner (E_max: 86% of inhibition for 3 mg/ml and 52% de-inhibition for 1 mg/ml). This pre-treatment also induced a significant attenuation of the norepinephrine-induced contraction in a concentration-dependent manner (E_max: 72.7% of inhibition for 3 mg/ml and 27% de inhibition for 1 mg/ml) in a Ca²⁺ free medium. Upon analyzing the composition of the extract, the presence of p-coumaric acid, isovitexin, luteolin and chrysoeriol were found. Luteolin (CE₅₀: 1.5 μg/ml), chrysoeriol (CE₅₀: 13.2 μg/ml) and p-coumaric acid (CE₅₀: 95.2 μg/ml), isolated from the aqueous extract, caused dilatation of thoracic aortic rings pre-contracted with phenylephrine. Artemisia copa administered i.v. also induced a decrease in the mean arterial pressure but did not affect the heart rate in hypertensive rats.

Conclusions

The aqueous extract of Artemisia copa proved to have vasorelaxing and hypotensive effects through the inhibition of Ca²⁺ influx via membranous calcium channels and intracellular stores. The presence of luteolin, chrysoeriol and p-coumaric acid found in this plant could be involved in this effect.     

Effect of the Plant Matrix on the Uptake of Luteolin Derivatives-containing Artemisia afra Aqueous-extract in Caco-2 cells

Aim of the study

Luteolin is a major flavonoid constituent and a primary candidate that might contribute to the claimed in vivo protective effects of Artemisia afra (Jacq. Ex. Willd). However, an exhaustive search yielded no literature evidence on the absorption, metabolism and fate of this flavonoid from the traditional plant preparation. The purpose of this study was to investigate the effect of the plant matrix on the uptake of luteolin derivatives from Artemisia afra aqueous extract in human intestinal epithelial Caco-2 cells.

Materials and methods

Cell monolayers were incubated with 5, 10 and 20 μg/ml doses of luteolin aglycone, luteolin-7-0-glucoside, un-hydrolyzed or acid-hydrolyzed Artemisia afra extracts, and samples of 150 μl each were collected from both apical and basolateral sides of cells at 30, 60 and 120 min for HPLC and LC–MS analyses.

Results

After 1-h exposure, the uptake of luteolin aglycone and luteolin-7-0-glucoside from the un-hydrolyzed and acid-hydrolyzed extracts was significantly faster and quantitatively higher (i.e. >77% vs. <25% of the initial doses over the first 30 min, p < 0.05) than that from non-plant solutions. Apical to basolateral permeability coefficients for luteolin and its-7-0-glucoside in the extracts were 1.6- to 2-fold higher than that for the non-plant solutions. Glucuronidation was an important pathway of metabolism for luteolin in both non-plant and plant extract forms.

Conclusions

Luteolin in Artemisia afra aqueous extract, regardless of its form (i.e. whether aglycone and 7-0-glucoside), is taken up better and more efficiently metabolized than the aglycone and 7-0-glucoside forms administered as pure solutions in Caco-2 cells. Flavonoid actives from Artemisia afra plant extracts and especially traditionally prepared dosage forms may thus have better bioavailability, and consequently greater in vivo potency, than that predicted from studies done using the pure solutions.     

Anti-Helicobacter pylori activity of plants used in Mexican traditional medicine for gastrointestinal disorders

Aim of the study

Helicobacter pylori is the major etiological agent of chronic active gastritis and peptic ulcer disease and is linked to gastric carcinoma. Treatment to eradicate the bacteria failed in many cases, mainly due to antibiotic resistance, hence the necessity of developing better therapeutic regimens. Mexico has an enormous unexplored potential of medicinal plants. This work evaluates the in vitro anti-H. pylori activity of 53 plants used in Mexican traditional medicine for gastrointestinal disorders.

Materials and methods

To test the in vitro antibacterial activity, agar dilution and broth dilution methods were used for aqueous and methanolic extracts, respectively.

Results

Aqueous extracts of Artemisia ludoviciana subsp. mexicana, Cuphea aequipetala, Ludwigia repens,and Mentha × piperita (MIC 125 to <250 μg/ml) as well as methanolic extracts of Persea americana, Annona cherimola, Guaiacum coulteri, and Moussonia deppeana (MIC <7.5 to 15.6 μg/ml) showed the highest inhibitory effect.

Conclusions

The results contribute to understanding the mode of action of the studied medicinal plants and for detecting plants with high anti-Helicobacter pylori activity.     

Effect of ginkgolide B on striatal extracellular amino acids in middle cerebral artery occluded rats

Ethnopharmacological relevance

Ginkgo biloba leaves are traditionally used in China for its health-promoting properties. There is substantial experimental evidence to support the view that Ginkgo biloba extracts have neuroprotective properties under conditions such as hypoxia/ischemia.Although a number of studies have investigated that ginkgolide B, a purified terpene lactone component extracted from Ginkgo biloba leaves, is available “platelet activating factor (PAF) receptors antagonist”, “antioxidant” with a variety of actions, very little has been performed to explore the effect of ginkgolide B on extracellular amino acids in experimental animal of focal cerebral ischemia/reperfusion. In this study, the effect of ginkgolide B on the striatal extracellular levels of glutamate (Glu), aspartic acid (Asp), glycine (Gly) and γ-aminobutyric acid (GABA) was evaluated in rats undergone middle cerebral artery occlusion (MCAO) for 1 h followed by 23 h reperfusion.

Materials and methods

The Sprague-Dawley (SD) rats received intraperitoneal injections of ginkgolide B dissolved at a dose of 10 mg kg⁻¹ d⁻¹, 20 mg kg⁻¹ d⁻¹, or normal saline (NS) of same volume 3 d before the middle cerebral artery occlusion model establishment. Extracellular concentrations of glutamate, aspartic acid, glycine and GABA in striatum were monitored using in vivo microdialysis and analyzed using high-performance liquid chromatography. Excitotoxic index (EI) was calculated. Twenty-four hours after MCAO, the cerebral infarct volume was detected on 2,3,5-triphenyltetrazolium chloride-stained coronal sections.

Results

The result showed that administration of ginkgolide B (10 or 20 mg kg⁻¹) before ischemia reduced the ischemia-induced elevation of levels of glutamate, aspartic acid and glycine, increased the elevation of extracellular GABA, decreased the excitotoxic index and diminished the volume of cerebral infarction, although a clear concentration-response relationship was not found.

Conclusions

The present work provides the first evidence that ginkgolide B protects against cerebral ischemic injury by inhibiting excitotoxicity by modulating the imbalance of excitatory amino acids versus inhibitory amino acids, which may support the traditional use of Ginkgo biloba leaves for the treatment of stroke.