Protective effect of Danhong injection on cerebral ischemia–reperfusion injury in rats

Ethnopharmacological relevance

Danhong injection (DH), a Chinese medical product, is used extensively for the treatment of cerebrovascular diseases such as acutely cerebral infarction in clinic.

Aim of the study

To explore the protective effect and the relevant mechanisms of DH on cerebral ischemia–reperfusion (I/R) injury.

Materials and methods

Cerebral I/R injury was induced through four-vessel occlusion (4-VO) or middle cerebral artery occlusion (MCAO). Adult male SD rats were randomly divided into six kinds of groups: normal control group, sham-operated group, I/R injury group, DH-treated groups at doses of 0.5 ml/kg, 1.0 ml/kg and 2.0 ml/kg. The effects of DH on murine neurological deficits and cerebral infarct volume, 6-keto-prostagladin F_1α (6-keto-PGF_1α) level, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in brain tissue, as well as the activities of plasma tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) after I/R were evaluated. Moreover, the expressions of Bcl-2 and Bax protein were detected by immunohistochemistry.

Results

There was no significant difference between the control group and the sham-operated group based on the measurement indicators. Compared with the vehicle-treated group, rats treated with DH showed dose dependent reductions in brain infarction size, and improvement of neurological outcome. The level of 6-keto-PGF_1α and the activities of SOD and plasma t-PA were enhanced significantly, whereas the level of MDA and the activity of plasma PAI were declined significantly. The immunohistochemical staining results also revealed that the expression of Bcl-2 protein was up-regulated and that of Bax protein was down-regulated when exposed to DH.

Conclusion

DH demonstrates a strong ameliorative effect on cerebral I/R damage in rats by its anticoagulant, antithrombotic, antifibrinolytic and antioxidant activities. Furthermore, suppressing apoptosis through regulating Bcl-2 and Bax protein expressions should be another potential mechanism by which DH exerts its neuroprotective function.     

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.     

Effects of taraxasterol on iNOS and COX-2 expression in LPS-induced RAW 264.7 macrophages

Ethnopharmacological relevance

Taraxasterol was isolated from the Chinese medicinal herb Taraxacum officinale which has been frequently used as a remedy for inflammatory diseases. Our previous study has shown that taraxasterol inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in RAW 264.7 macrophages. To elucidate the underlying mechanism responsible for these effects, in the present study, we investigated the effects of taraxasterol on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, and mitogen-activated protein kinases (MAPKs) signaling pathway in LPS-induced RAW 264.7 macrophages.

Materials and methods

RAW 264.7 cells were pretreated with 2.5, 5 and 12.5 μg/ml of taraxasterol 1 h prior to treatment with 1 μg/ml of LPS. The mRNA expression levels of iNOS and COX-2 were examined by RT-PCR. The protein expression levels of iNOS and COX-2, and the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), p38 and c-Jun N-terminal kinase (JNK) MAPKs were measured by Western blot.

Results

The mRNA and protein expression levels of iNOS and COX-2 were inhibited by taraxasterol in a concentration-dependent manner. Further studies revealed that taraxasterol suppressed the phosphorylation of ERK1/2 and p38 in LPS-induced RAW 264.7 macrophages.

Conclusions

These results indicate that taraxasterol inhibits iNOS and COX-2 expression by blocking ERK1/2 and p38 MAPKs signaling pathway.     

Anti-inflammatory and anti-arthritic activity of total flavonoids of the roots of Sophora flavescens

Ethnopharmacological relevance

The roots of Sophora flavescens have long been used in Chinese medicine for the treatment of fever, inflammatory disorders, ulcers and skin burns. Sophora flavescens contains flavonoids and alkaloids.

Aim of the study

This study was conducted to develop a plant-based anti-inflammatory agent focused on chronic inflammatory disorders. To accomplish this, the alkaloid-free prenylated flavonoid-enriched fraction (PFS) of rhizomes of Sophora flavescens was prepared and its in vitro and in vivo anti-inflammatory activities were then evaluated for the first time.

Materials and methods

The inhibitory activity of PFS on PGE₂, NO, IL-6 and TNF-α production of lipopolysaccharide (LPS)-treated RAW 264.7 cells was measured. Additionally, adjuvant-induced arthritis in rats was used as an animal model of chronic inflammation to establish the in vivo anti-inflammatory effects of PFS.

Result

PFS inhibited cyclooxygenase-2 (COX-2)-catalyzed PGE₂ and inducible nitric oxide synthase (iNOS)-catalyzed NO production by lipopolysaccharide (LPS)-treated RAW 264.7 cells at 10–50 μg/ml, and these effects primarily occurred via COX-2 inhibition and iNOS down-regulation, respectively. PFS also inhibited IL-6 and TNF-α production. When tested against adjuvant-induced arthritis in rats (chronic inflammation), PFS strongly inhibited arthritic inflammation when administered orally at doses of 10–100 mg/kg/day. In addition, PFS administered orally potently inhibited acetic acid-induced writhing in mice.

Conclusions

Our results suggest that PFS inhibits chronic inflammatory response and the inhibition of proinflammatory molecules such as COX-2, iNOS and IL-6 may contribute, at least in part, to the anti-inflammatory activity in vivo. Overall, these results indicate that PFS from Sophora flavescens may have the potential for treatment of chronic inflammatory disorders such as rheumatoid arthritis.     

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.     

Antihypertensive effects of extract from Picrasma quassiodes (D. Don) Benn. in spontaneously hypertensive rats

Ethnopharmacologica relevance

Picrasma quassiodes (D. Don) Benn. (PQB) is a widely used herbal medicine used for gastroenteritis, snakebite, infection and hypertension in China. The aim of the study was to investigate the possible antihypertensive mechanisms on spontaneously hypertensive rats (SHR) of the extract from Picrasma quassiodes (D. Don) Benn.

Materials and methods

In the in vivo study, extract from Picrasma quassiodes (D. Don) Benn. at the dose of 50, 100, 200 mg/kg and captopril (12.5 mg/kg) were administrated to different group of SHR rats by gavage for six consecutive weeks after the blood pressures were firstly measured. At the end of the study, rats serum nitric oxide (NO) was measured by the nitrate reductase method; superoxide dismutase (SOD) and malondialdehyde (MDA) activities were measured by the colorimetric method; the expression of aorta endothelial nitric oxide synthase (eNOS) was measured by immunohistochemical analysis.

Results

The results showed that the oral administration of PQB could lower the systolic blood pressure (SBP) of SHR rats. In addition, the serum level of NO in SHR treated with PQB (100 and 200 mg/kg) was increased dramatically (P<0.05, P<0.01), but administration with captopril had no significant effect. The expression of aorta eNOS was markedly increased when treated with PQB. The serum SOD levels were increased with treatment of PQB (100 and 200 mg/kg; P<0.05, P<0.01). All the effects of these parameters were comparable to that of the SHR control group.

Conclusions

Our results disclosed that PQB is effective to lower blood pressure of SHR, its antihypertensive effect is probably associated with lowering oxidative stress by reducing SOD activity, preserving endothelial function and increasing the expression of eNOS to regulate NO and directly relax artery.     

Evaluation of reproductive and developmental toxicities of Pu-erh black tea (Camellia sinensis var. assamica) extract in Sprague Dawley rats

Ethnopharmacological relevance

Pu-erh black tea, which is obtained by first parching crude green tea leaves and followed by secondary fermentation with microorganisms, has been believed to be beneficial beverages for health in PR China. But its potential toxicity when administered at a high dose as concentrated extract has not been completely investigated.

Aim of the study

The present study was aimed at evaluating potential reproductive and developmental toxicities of Pu-erh black tea extract (BTE) in Sprague Dawley rats.

Materials and methods

Growing rats were given BTE by gavage at levels of 0, 200, 700 and 2500 mg/kg/day as the F₀ generation in reproductive toxicity study. Additionally, BTE was administered to mate female rats from gestation day 0.5 through 19.5 at the doses of 0, 200, 700 and 2500 mg/kg/day to evaluate the developmental toxicity.

Results

In the reproductive toxicity study, only 2500 mg/kg/day BTE reduced the body weight gain and altered the relative organ weights including testes, prostata and ovary both for F₀ parents and F₁ offspring compared to the controls. High dose of BTE (2500 mg/kg/day) administration caused developmental disturbances in embryo-to-foetus period including resorbed embryos, decreased embryo size and skeletal anomalies.

Conclusion

In conclusion, the no-observed-adverse-effect level of BTE is 700 mg/kg/day both for reproductive toxicity and developmental toxicities.     

Antihyperglycaemic activity of aqueous leaf extract of Combretum micranthum (Combretaceae) in normal and alloxan-induced diabetic rats

Aim of the study

To investigate antidiabetic effect of the leaves of Combretum micranthum G. Don, a medicinal plant used for treating diabetes in Northwestern Nigeria.

Materials and methods

Three doses (100 mg/kg, 200 mg/kg and 400 mg/kg) of the aqueous leaf extract of Combretum micranthum were administered to normal glucose loaded, subdiabetic and diabetic rats.

Results

Of the doses tested, 100 mg/kg of the extract was the most effective. It produces a significant hypoglycaemic and antidiabetic activity comparable to the effect of standard drug (0.6 mg/kg glibenclemide).

Conclusion

This study demonstrated the potential antidiabetic property of aqueous leaf extract of Combretum micranthum thus justifying its traditional usage.     

Huangqi−Honghua combination and its main components ameliorate cerebral infarction with Qi deficiency and blood stasis syndrome by antioxidant action in rats

Ethnopharmacological relevance

Combination of Radix Astragali (Huangqi) and Carthamus tinctorius L. (Honghua) has been extensively used as traditional herb medicine in China for the treatment of stroke and myocardial ischemia diseases with Qi deficiency and blood stasis (QDBS) syndrome.

Aim

To investigate the effect of Huangqi−Honghua combination (HH) and its main components astragaloside IV (AS-IV) and Hydroxysafflor yellow A (HSYA) on cerebral ischemia-reperfusion (IR) with QDBS in rat model.

Materials and methods

Male rats were randomly divided into the following six groups: sham group, QDBS+I/R model group and treatment group including AS-IV, HSYA, AS-IV+HSYA and HH. The whole blood viscosity (WBV), plasma viscosity (PV), neurological examination, infarct volume, histopathology changes and some oxidative stress markers were assessed after 24 h of reperfusion.

Results

HH and its main components AS-IV+HSYA could significantly decrease WBV, PV, and also significantly ameliorate neurological examination and infarct volume after 24 h of reperfusion. They also significantly increased expression of Nuclear factor erythroid 2-related factor 2 (Nrf2), activities of antioxidants, such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px), led to decrease levels of malondialdehyde (MDA) and reactive oxygen species (ROS).

Conclusion

AS-IV and HSYA are responsible for the main curative effects of HH. The study may provide scientific information to further understanding the mechanism(s) of HH and its main components in removing blood stasis and ameliorating cerebral infarction. Additionally, AS-IV and HSYA appear to have synergistic effects on neuroprotection.     

Huang-Lian-Jie-Du-Decotion induced protective autophagy against the injury of cerebral ischemia/reperfusion via MAPK-mTOR signaling pathway

Ethnopharmacological relevance

Huang-Lian-Jie-Du-Decotion (HLJDD, Hwangryun-Hae-Dok-Decotion in Japan), an ancient antipyretic and detoxifying traditional Chinese medicine formula, was reported to have protective effect on ischemic stroke.

Aim of the research

To investigate the therapeutic effect of HLJDD on ischemic stroke and explore its mode of action.

Material and methods

A model of ischemic stroke in the rat was established after transient middle cerebral artery occlusion (MCAO) followed by reperfusion. Rats were assigned randomly to groups of control, sham, transient ischemia/reperfusion (I/R), and three treatment groups by HLJDD at 2.5, 5.0, 10.0 mg/kg. The neurological deficit, the cerebral infarct size, morphology abnormality, biochemical parameters were examined, and the levels of relevant proteins were determined by immunoblotting analysis to evaluate the protective effects of HLJDD on ischemic stroke and explore the underlying mechanism.

Results

Compared with I/R group, HLJDD significantly ameliorated neurological deficit and histopathology changes, decreased infarct area, and restored the levels of biochemical indicators including nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), glutathione disulfide (GSSG), total superoxide dismutase (T-SOD), Cu/Zn-SOD, Mn-SOD and glutathione peroxidase (GSH-PX). HLJDD also notably elevated the levels of microtubule-associated protein1 light chain 3 (LC3), Beclin-1, and other autophagy related genes (Atgs), promoted the activation of extracellular signal-regulated kinases (ERK), protein kinase B (Akt), 3-phosphoinositide-dependent kinase (PDK1), and inhibited the activation of mammalian target of rapamycin (mTOR), c-Jun N-terminal protein kinases (JNK), p38, phosphatase and tensin homolog (PTEN).

Conclusion

HLJDD showed neuroprotective effects on ischemic stroke, at least in part to the induced protective autophagy via the regulation of mitogen-activated protein kinase (MAPK) signals. This Akt-independent protective autophagy is favorable in the treatment of stroke, avoiding unfavorable side-effects associated with the inactivation of Akt. The efficacy of HLJDD on ischemic stroke and its safety warranted by its long-term clinical use in traditional Chinese medicine favored further study to develop HLJDD as an effective therapeutic agent to treat ischemic stroke.     

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.     

Anti-inflammatory activity of flavonoids from Cayaponia tayuya roots

Ethnopharmacological relevance

Taiuiá or tayuya (Cayaponia tayuya, Cucurbitaceae) is a climbing, lignified plant with a large swollen root that has traditionally been used as an anti-inflammatory and anti-rheumatic agent in the folk medicine of Brazil, Peru, and Colombia.

The aim of the study

We have assayed the pharmacological properties of a flavonoid fraction obtained from the butanol extract of Cayaponia tayuya roots using two models of topical mouse ear oedema, paying special attention to its influence on the induction on pro-inflammatory enzymes and peptidic mediators.

Material and methods

The in vivo experiments involved both the acute oedema induced by a single application of TPA and the subchronic inflammation brought on by repeated applications of TPA. The effects on the induction of pro-inflammatory enzymes and peptidic mediators in RAW 264.7 macrophages were analyzed with the aid of Western blot analysis.

Results

The extract was identified as a mixture of flavonoids in which vicenin-2, spinosin, isovitexin, and a mixture of swertisin and isoswertisin were found. In acute TPA-induced oedema in mouse ears, the flavonoid-enriched fraction (at a dose of 0.5 mg/ear) inhibited the oedema by 66% (4.2 ± 0.6 mg vs. 12.3 ± 1.4 mg, P < 0.01) while in the subchronic model, the inhibition reached 37% at a dose of 0.5 mg/ear × 7 applications (7.5 ± 0.6 mg vs. 11.9 ± 1.3 mg, P < 0.05). When assayed in vitro, the flavonoid showed no toxicity at 33.45 μg/mL on RAW 264.7 macrophages. Although the nitric oxide production in these cells was moderately reduced (42%) at 33.45 μg/mL, the flavonoid-enriched fraction had no effect on TNF-α production. In addition, at 22.30 μg/mL, the test sample inhibited both iNOS and COX-2 expression by 98% and 49%, respectively.

Conclusion

These results indicate that the anti-inflammatory activity of flavonoids from tayuya roots most likely stems from their inhibition of the induction of the enzymes COX-2 and iNOS.     

Suppression of nitric oxide production in activated murine peritoneal macrophages in vitro and ex vivo by Scrophularia striata ethanolic extract

Ethnopharmacological relevance

Scrophularia striata (Scrophulariaceae), a traditional Iranian medicine, has been used for the treatment of allergy, rheumatics and chronic inflammatory disorders.

Aim of the study

In the present study, we investigated the in vitro and ex vivo suppressive effects of Scrophularia striata ethanolic extract on nitric oxide production in mouse peritoneal macrophages.

Materials and methods

Peritoneal macrophages were harvested by lavaging with ice cold phosphate buffer saline. Macrophages obtained from mice not treated were cultured with 10 μg/mL lipopolysaccaride (LPS), 20 U/mL interferon-γ (IFN-γ), and various concentrations of Scrophularia striata extract for the in vitro experiments and those obtained from mice treated with different doses of the extract for 7 days were cultured with 10 μg/mL LPS, 20 U/mL IFN-γ for the in vivo experiments. Nitrit levels were measured by using the diazotization method based on the Griess reaction, which is an indirect assay for NO production.

Results

In vitro exposure of mouse peritoneal macrophages with various concentrations of Scrophularia striata extract (10, 50 and 100 μg/mL) significantly suppressed NO production in a dose-dependent manner. In vivo administration of Scrophularia striata extract (50 and 100 mg/kg) to Balb/c mice inhibited LPS and IFN-γ induced production of NO in the isolated mouse peritoneal macrophages ex vivo in a dose-dependent manner. Exposure to Scrophularia striata extract had no effect on cell viability.

Conclusion

The results of the study demonstrated that the Scrophularia striata extract inhibit NO production in activated murine macrophages and we suggest that Scrophularia striata may be used in treating the inflammatory diseases.     

The neuroprotective effect of modified “Shengyu” decoction is mediated through an anti-inflammatory mechanism in the rat after traumatic brain injury

Ethnopharmacological relevance

“Shengyu” decoction, a traditional Chinese medicine, has been used to treat diseases with deficit in “qi” and “blood” induced frequently by profound loss of blood or by long sores with heavy pus, in which a potential anti-inflammatory effect is implied. The modified “Shengyu” decoction (MSD) used in the present study was designed on the basis of the “Shengyu” decoction, additional four herbs were added in. Many ingredients in these herbs have been demonstrated to be anti-inflammatory and thus MSD may be used for the treatment of traumatic brain injury (TBI). To evaluate the neuroprotective effect and the underlying mechanisms of MSD on the rat brain after TBI.

Materials and methods

TBI was induced in the right cerebral cortex of male adult rats using Feeney's weight-drop method. The rats were administered a gavage of MSD (0.5, 1.0 or 2.0 ml/200 g) 6 h after TBI. The neurological functions, brain water content, contusion volume, and neuron loss were determined. The levels of TNF-α, IL-1β, IL-6, and IL-10 and the number of GFAP- and Iba1-positive cells in the brain ipsilateral to TBI were also measured. Moreover, the influence of MSD on these variables was observed at the same time.

Results

The neurological deficits, brain water content, and neuron loss were significantly reduced after 1.0 or 2.0 ml/200 g of MSD treatment but not after 0.5 ml/200 g. In addition, treatment with MSD (1.0 ml/200 g) significantly increased the level of IL-10 and reduced the level of TNF-α and IL-1β and the number of GFAP- and Iba1-positive cells after TBI. However, the contusion volume of brain tissue and the expression of IL-6 were not significantly changed.

Conclusion

MSD may be a potential therapeutic for the treatment of TBI because MSD alleviated secondary brain injury induced by TBI. In addition, MSD inhibited the inflammatory response through reducing the expression of inflammatory cytokines and the activation of microglial cells and astrocytes in the brain tissue of rats after TBI. Therefore, a potential anti-inflammatory mechanism of the “Shengyu” decoction was confirmed, which may be one of the main reasons of “Shengyu” decoction used to treat diseases with obvious inflammatory responses.     

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.     

Aqueous extract of Astragali Radix ameliorates proteinuria in adriamycin nephropathy rats through inhibition of oxidative stress and endothelial nitric oxide synthase

Aim of the study

To investigate the effects of aqueous extract of Astragali Radix (ARE) on the oxidative stress status and endothelial nitric oxide synthase level in adriamycin (ADR) nephropathy rats.

Materials and methods

ADR nephropathy rats were randomly treated with ARE (2.5 g/kg/d, n = 6, ARE group), or benazepril (10 mg/kg/d, n = 6, angiotensin-converting enzyme inhibitor (ACEI) group) for ten weeks. Serum urea nitrogen, creatinine, albumin, total protein, cholesterol and 24-h urinary protein concentration were determined. Renal cortex catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), malondialdehyde (MDA) activities, and 24-h urinary NO₃⁻/NO₂⁻ excretion were determined by chromatometry. Renal cortex cyclic guanosine monophosphate (cGMP) level was measured by enzyme immunoassay and eNOS expression was determined by immunohistochemistry.

Results

ARE and ACEI treatments could remarkably reduce more 24 h urinary protein excretion than that in ADR group (88.32 ± 9.96 mg, 81.78 ± 16.28 mg vs. 153.91 ± 28.63 mg, P < 0.01), and there was no difference between ARE and ACEI group. Renal cortex CAT, GSH-Px activities in ARE and ACEI group were significantly higher than ADR group, and renal cortex SOD activity in ARE group was higher than ADR group. Renal cortex MDA activity, cGMP level, and glomerular and tubular eNOS expression in ARE and ACEI group were lower than that in ADR group, and 24-h urinary NO₃⁻/NO₂⁻ excretion in ARE group was lower than ADR group. Renal cortex MDA content (r = 0.895, P < 0.01), cGMP content (r = 0.666, P < 0.01) and eNOS expression in glomerulus (r = 0.910, P < 0.01) were strongly positively associated with 24 h urinary protein excretion. And renal cortex SOD content was negatively associated with 24 h urinary protein excretion (r = −0.861, P < 0.01).

Conclusions

ARE may ameliorate the proteinuria by suppressing the over expression of eNOS, and inhibiting the oxidative injury in ADR nephropathy rats.     

Anti-inflammatory and antitumoural effects of Uncaria guianensis bark

Ethnopharmacological relevance

Uncaria guianensis (Aublet) Gmell (Rubiaceae) is a medicinal plant from the jungles of South and Central America, used to treat cancer, arthritis, diabetes, and inflammation. Evaluate the anti-inflammatory and anti-tumor effects of Uncaria guianensis preparations.

Materials and methods

Bio-guided fractionation of a hydroethanolic extract of Uncaria guianensis was performed, evaluating the fractions and subfractions for their effect on inflammatory mediators, tumour necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and prostaglandin E₂ (PGE₂) by ELISA and nitric oxide (NO) by the Griess reaction in cultured supernatant from RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS). The expression of cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS) and inhibitor of κB (IκB) were investigated in RAW 264.7 macrophages by flow cytometry. The activity of NF-κB in HeLa cells transfected with a luciferase reporter system was determined. The effect of Uncaria guianensis on the inflammatory response in vivo was assessed in BALB/c mice stimulated with LPS, on rat paw oedema induced by carrageenan, and on tumour growth and lung metastasis in BALB/c mice inoculated with 4T1 mammary tumour cells. Immune cell infiltrates and inflammatory mediators were evaluated in the tumour by immunohistochemistry.

Results

Sub-fraction Ug AIV inhibited, to varying degrees, NO, TNF-α, IL-6 and PGE₂ production by macrophages in vitro (30 μg/ml) and in the serum of LPS-challenged mice (5 mg/kg). Macrophage expression of Cox-2 was inhibited (35%), IκB degradation was completely inhibited and NF-κB activation was inhibited (70%) by Ug AIV at 30 μg/ml. Ug AIV decreased paw oedema by 86% (5 mg/kg) and serum NO and TNF-α by 45% and 65% respectively. Ug AIV reduced 4T1 mammary tumour growth by 91% on day 33 post-inoculation as well as the levels of serum NO, IL-6 and TNF-α in the same animals. Ug AIV decreased the number of tumour-infiltrating T lymphocytes, macrophages and neutrophils as well as the number of cells positive for COX-2, iNOS, IL-6, TNF-α and p65.

Conclusions

As Ug AIV was not cytotoxic for tumour cells or macrophages, its anti-tumour effect may be due to a reduction in pro-tumoural inflammatory processes in the tumour microenvironment, possibly mediated through NF-κB.