Effects of San'o-shashin-to and the constituent herbal medicines on theophylline-induced increase in arterial blood pressure of rats

Antihypertensive constituents in Sanoshashinto

It has been reported that Sanoshashinto (SanHuangXieXinTang, 三黃瀉心湯), which is composed of Rhei Rhizoma, Scutellariae Radix, and Coptidis Rhizoma, exhibits vasorelaxant effects in vitro and lowers blood pressure of patients. Based on this discovery, in this study, a mixture containing those three materials and combinations of them were extracted with methanol, and the extracts were fractionated into different parts. Effects of all extracts and fractions on high concentration of potassium chloride (High K⁺)- or noradrenaline (NA)-induced contractions of isolated rat aortic rings or helical strips were examined. Qualitative and quantitative HPLC analyses of the extracts and the fractions revealed that the contents of baicalin and berberine in Sanoshashinto methanol extract (SHXXTM) were higher than those of the other constituents. All pharmacological and HPLC data were analyzed by principal component analysis (PCA) software and the results indicated that baicalin, berberine, palmatine, baicalein, and wogonoside contributed significantly to the pharmacological activity. Furthermore, spontaneously hypertensive rats (SHRs) that were orally given SHXXTM or a baicalin–berberine combination showed significantly reduced increase in the rate of systolic blood pressure (SBP) compared to the control group. These findings suggested that Sanoshashinto has significant vasorelaxant effects in vitro and antihypertensive effects in vivo, and baicalin and berberine, which were the principal constituents of Scutellariae Radix and Coptidis Rhizoma, were the main antihypertensive constituents in Sanoshashinto. It was speculated that baicalin and berberine produced vasorelaxant effects by activating the NO/cGMP pathway and that the BK_Ca channel and the DAG/PKC/CPI-17 pathway were also involved.

Simultaneous quantification of six indicator compounds in Wen-Qing-Yin by high-performance liquid chromatography-diode array detection

A simple gradient high-performance liquid chromatography with diode array detection (HPLC-DAD) method was used to simultaneously to analyze characteristics of six indicator compounds in the traditional Chinese medicine (TCM) formulation Wen-Qing-Yin (WQY). Separate optimization was performed using a Cosmosil C18 column gradient method with 0.1% formic acid in both mobile phases of aqueous and acetonitrile (ACN), at a flow rate, detection wavelength, and sample volume of 1.8 mL/min, 268 nm, and 10 μL, respectively. The linear regression of six active compounds berberine (BER), baicalin (BAI), ferulic acid (FER), geniposide (GEN), hydorxymethoxylfurfural (HMF), and paeoniflorin (PAE) was produced at the concentration range of 10–2000 μg/mL. The method validation revealed an acceptable precision (intra- and inter-day precision < 3.39% and 4.11%, respectively) and recovery (85.60–110.45% and 86.58–110.90%), a recovery range of 86.61–109.42%, and sensitivity (limit of detection [LOD] and limit of quantification [LOQ] values were in the range of 0.03–3.13, and 0.08–9.38 μg/mL, respectively) while the calibration curves were linear with a correlation coefficient (R²) ranging from 0.9966 to 0.9989. The qualitative and quantitative analyses were performed by direct comparison of the peaks of the WCY extract to retention times of reference standards. Additionally, principal component analysis (PCA) successfully discriminated four purchased commercial samples of all six indicator constituents, and the present results indicate their comprehensive potential usefulness for qualitative and quantitative analyses of the WQY decoction and its commercial products.

The Effects of Chunghyul-Dan (A Korean Medicine Herbal Complex) on Cardiovascular and Cerebrovascular Diseases: A Narrative Review

Chunghyul-dan (CHD) is a herbal complex containing 80% ethanol extract and is composed of Scutellariae Radix, Coptidis Rhizoma, Phellodendri Cortex, Gardeniae Fructus, and Rhei Rhizoma. We have published several experimental and clinical research articles on CHD. It has shown antilipidemic, antihypertensive, antiatherosclerotic, and inhibitory effects on ischemic stroke recurrence with clinical safety in the previous studies. The antilipidemic effect of CHD results from 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase and pancreatic lipase-inhibitory activity. The antihypertensive effect likely results from the inhibitory effect on endogenous catecholamine(s) release and harmonization of all components showing the antihypertensive effects. Furthermore, anti-inflammatory and antioxidant effects on endothelial cells are implicated to dictate the antiatherosclerotic effects of CHD. It also showed neuroprotective effects on cerebrovascular and parkinsonian models. These effects of CHD could be helpful for the prevention of the recurrence of ischemic stroke. Therefore, we suggest that CHD could be a promising medication for treating and preventing cerebrovascular and cardiovascular diseases. However, to validate and better understand these findings, well-designed clinical studies are required.

Subchronic toxicity study of Coptidis rhizoma in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Coptidis Rhizoma (CR) is a medical herb from the family Ranunculacease that has been used to treat gastroenteritis, dysentery, diabetes mellitus, and severe skin diseases.

AIM OF THE STUDY

To evaluate the no-observed-adverse-effect level (NOAEL) and the toxicity of CR, following repeat oral administration to rats for 13 weeks.

MATERIALS AND METHODS

CR was administered by oral gavage to groups of rats (n=10/group, each sex) at dose levels of 0 (control), 25, 74, 222, 667 or 2000 mg/kg/day 5 times per week for 13 weeks. Mortality, clinical signs, body weights, food consumption, hematology, serum chemistry, urinalysis, vaginal cytology and sperm morphology, organ weights, gross and histopathological findings were compared between control and CR groups.

RESULTS

Urinalysis showed a significant increase in N-acety1-β-glucosaminidase in males in the 2000 mg/kg/day group (P<0.01). However, no mortality or remarkable clinical signs were observed during this 13-week study. No adverse effects on body weight, food consumption, hematology, serum chemistry, organ weights, gross lesion, histopathology, vaginal cytology, sperm motility, or deformity were observed in the males or female rats treated with CR.

CONCLUSIONS

On the basis of these results, the NOAEL of CR is determined to be 667 mg/kg/day for males and 2000 mg/kg/day for females.

Reduced system exposures of total rhein and baicalin after combinatory oral administration of rhein, baicalin and berberine to beagle dogs and rats

ETHNOPHARMACOLOGICAL RELEVANCE

Rhein (Rh), baicalin (BG) and berberine (Be) are important coexisted constituents of San-Huang-Xie-Xin-Tang, which was widely used in traditional Chinese medicine for the treatment of gastritis, hypertension, gastric bleeding and peptic ulcers, etc.

AIM OF THE STUDY

Based on the extensive phase II conjugation reactions of polyphenols (Rh and BG) in vivo, the aims of the present study were to investigate the effects of combination (Rh, BG and Be) on the system exposures of total Rh and BG involving the phase II conjugates metabolites and its possible mechanism.

MATERIALS AND METHODS

A 3×3 Latin square single heavy design was used to investigate the pharmacokinetics influence of total Rh and BG after combination of Be by treating plasma samples with β-glucuronidase/sulfatase both in beagle dogs and Wistar rats. In vitro and in situ experiment models including in situ rat intestinal perfusion, Caco-2 cell monolayer transport and small intestinal flora incubation system were used to discuss the possible mechanism.

RESULTS

The results of pharmacokinetic interactions showed that combination significantly reduced the system exposures of total Rh and BG. Compared with Rh or BG alone, the mean area under concentration-time curves (AUC(0-t)) of total Rh and BG reduced by 31% and 77% in beagle dog experiment. In Wistar rat experiment, the AUC(0-t) of total Rh and BG reduced by 22% and 21%. Subsequently, the results of in situ rat intestinal perfusion and small intestinal flora incubation system tests revealed that combination may decrease the absorption and metabolism of BG. However, combination could not affect the transport profile of BG across the Caco-2 cell. Moreover, combination did not affect the absorption or metabolism profile of Rh in all three in situ/in vitro experiments.

CONCLUSIONS

It was deduced that the possible mechanism of the reduction of the system exposures of total Rh and BG was related to that combination decreased the metabolism of BG to B or the phase II conjugates of Rh/BG excreted from liver/bile duct to their free aglycones in vivo by inhibiting intestinal flora. The potent effects of combination on the phase II conjugates of Rh and B in pharmacokinetics, shown in this paper, indicated that more attention should be paid to the phase II conjugates metabolites of these polyphenols (undergo extensive phase II conjugation reactions in vivo) when applied herbal products composed of these coexist compounds.

Bojesodok-eum, a Herbal Prescription, Ameliorates Acute Inflammation in Association with the Inhibition of NF-κB-Mediated Nitric Oxide and ProInflammatory Cytokine Production

Bojesodok-eum (BSE) is a herbal prescription consisting of Coptidis Rhizoma and Scutellariae Radix as main components. This paper investigated the effects of BSE on the induction of nitric oxide (NO), prostaglandin E(2) (PGE(2)), and proinflammatory cytokines that are caused by lipopolysaccharide (LPS) in murine macrophage cell line and on the paw edema formation in animals. Administration of BSE (0.3 g/kg and 1 g/kg) in rats significantly inhibited carrageenan-induced paw edema formation, as did dexamethasone, an anti-inflammatory positive control drug. In cell model, treatment of BSE decreased the production of NO and PGE(2) in RAW264.7 cells stimulated by LPS. BSE also inhibited the expression of iNOS and COX-2 protein as well as COX activity in a concentration-dependent manner. Consistently, BSE suppressed the ability of LPS to produce TNF-α, interleukin-1β, and interleukin-6. LPS treatment induced nuclear NF-κB level and I-κBα phosphorylation, which were inhibited subsequent treatment of BSE, suggesting its repression of LPS-inducible NF-κB activation. BSE abrogated the induction of NO, PGE(2), and proinflammatory cytokines, as well as iNOS and COX-2 protein expression in RAW264.7 cells stimulated by LPS as mediated with NF-κB inhibition.

Anti-hypertensive Effect of Chunghyul-dan (Qingxue-dan) on Stroke Patients with Essential Hypertension

Hypertension is one of the modifiable risk factors for stroke. Lowering blood pressure is helpful for primary and secondary prevention of stroke. This study is aimed to assess the efficacy of Chunghyul-dan on stroke patients with stage 1 hypertension using 24 hours ambulatory blood pressure monitoring (24ABPM). Forty hospitalized stroke patients with stage 1 hypertension were included in the study and they were randomly assigned into two groups: group A was treated with Chunghyul-dan 1200 mg once a day for 2 weeks, while group B was not. Twelve subjects were dropped out because of unexpected early discharge or data errors, thus the remaining 28 subjects were included in the final analysis (15 in group A and 13 in group B). Blood pressure was monitored every 30 minutes for 24 hours at baseline and 2 weeks after medication. Blood pressure, pulse rate, trough/peak ratio (TPR) [the value calculated by dividing the blood pressure change at trough (22 to 24 hours after drug intake) by the change at peak (2 adjacent hours with a maximal blood pressure reduction between the second and eighth hour after drug intake)] and smoothness index (SI) (the value calculated as the ratio between the average of the 24 hours, treatment-induced blood pressure changes and its standard deviation) were compared to assess the efficacy of Chunghyul-dan. To assess the safety of Chunghyul-dan, any adverse effects during medication period were monitored. There was no significant difference in the baseline assessment between the two groups. Systolic blood pressure was lower in group A than in group B (141.37 ± 8.96 mmHg versus 132.28 ± 9.46 mmHg , P = 0.03), while diastolic blood pressure and pulse rate had no significant difference between the two groups. Systolic TPR and SI was 0.87 and 1.04 in group A, respectively. This suggests that Chunghyul-dan have anti-hypertensive effect on stroke patients with stage 1 hypertension.

Hepatoprotective effect and its possible mechanism of Coptidis rhizoma aqueous extract on carbon tetrachloride-induced chronic liver hepatotoxicity in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Coptidis rhizoma is traditionally used for heat-clearing and toxic-scavenging and it belongs to liver meridian in Chinese medicine practice. Clinically, Coptidis rhizoma can be used for hepatic and biliary disorders, yet details in the therapies of liver diseases and underlying mechanism(s) remain unclear. Our previous study demonstrated that Coptidis rhizoma aqueous extract (CRAE) against CCl(4)-induced acute liver damage was related to antioxidant property. In the present study, the protection of CRAE on chronic liver damage induced by carbon tetrachloride (CCl(4)) in rats and its related mechanism were explored.

MATERIALS AND METHODS

The CCl(4)-induced chronic liver damage model was established, and CRAE's protective effect was examined. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity, serum and liver superoxide dismutase (SOD) activity were then measured. The histological changes were observed under microscopy and then computed in numerical score. The normal or damaged cells were isolated and related signaling pathway was evaluated.

RESULT

Serum AST and ALT activities were significantly decreased in rats treated with different doses of CRAE, indicating its protective effect against CCl(4)-induced chronic liver damage. Observation on serum SOD activity revealed that CRAE might act as an anti-oxidant agent against CCl(4)-induced chronic oxide stress. Histological study supported these observations. Erk1/2 inhibition may take part into CRAE's effect on preventing hepatocyte from apoptosis when exposed to oxidative stress.

CONCLUSION

CRAE showed protective effect against CCl(4)-induced chronic liver damage in rats and its potential as an agent in the treatment of chronic liver diseases by protecting hepatocyte from injury.

Nitric oxide-dependent hypotensive effects of wax gourd juice

ETHNOPHARMACOLOGICAL RELEVANCE

The wax gourd (Benincasa hispida (Thunb) Cong.) is a long-season vegetable that has been used in traditional Chinese medicine to treat high blood pressure. However, precise details of its effect and the mechanism of action involved are still lacking.

MATERIALS AND METHODS

Ten-fold-condensed wax gourd juice was used for the experiments. We measured (1) blood pressure of anesthetized normal Wistar rats in vivo, (2) isolated rat aortic contraction and relaxation, and (3) nitric oxide production from cultured porcine endothelial cells. The rats mentioned had not been treated with the investigational medicine.

RESULTS

Intravenous injection of the juice produced a dose-dependent decrease in blood pressure. Treatment with the juice induced concentration-dependent relaxation of isolated rat aortic rings that had been precontracted with noradrenaline. The relaxation induced by the juice was strongly inhibited by treatment with the nitric oxide (NO) synthase inhibitor N(G)-nitro-l-arginine methyl ester hydrochloride (l-NAME) or endothelial denudation. Treatment with the juice produced NO from cultured porcine aortic endothelial cells. This NO production was significantly inhibited by l-NAME.

CONCLUSIONS

The present findings suggest that wax gourd juice exerts a hypotensive effect via endothelium-dependent vasodilation. The main endothelium-derived relaxing factor involved might be NO.

Screening the bioactive compounds in aqueous extract of Coptidis rhizoma which specifically bind to rabbit lung tissues beta2-adrenoceptor using an affinity chromatographic selection method

A receptor affinity chromatographic selection method was developed for screening the bioactive compounds binding to beta(2)-adrenoceptor (beta(2)-AR) in Coptidis rhizome. The bioactive compounds were analyzed by molecular recognition with a beta(2)-AR affinity column. The retention compounds eluted from the beta(2)-AR column were separated online with reverse-phase high-performance liquid chromatography by column switching technology, and identified by a coupled ion-trap mass spectrometer. Four compounds were screened as the bioactive compounds of Coptidis rhizome and identified as 2,9,10-trimethoxy-3-hydroxyl-protoberberine (jateorhizine), 2,3-methylenedioxy-9-methoxy-protoberberine, 2,3,9,10-tetramethoxy-protoberberine (palmatine) and 2,3-methylenedioxy-9,10-dimethoxy-protoberberine (berberine). The association constants of jatrorrhizine, palmatine and berberine to the beta(2)-AR were determined by the zonal elution method with standards. Berberine and palmatine had only one type of binding site on the immobilized beta(2)-AR. Their association constants were (2.28+/-0.11)x10(4)/M and (3.00+/-0.10)x10(4)/M, respectively. Jatrorrhizine had at least two type of binding sites on the immobilized beta(2)-AR, and the corresponding association constants were (2.20+/-0.09)x10(-4)/M and (6.78+/-0.001)x10(5)/M.

Potential ex vivo immunomodulatory effects of San-Huang-Xie-Xin-Tang and its component herbs on mice and humans

AIM OF THE STUDY

San-Huang-Xie-Xin-Tang (SHXXT), an important Chinese medicine formula, contains Rhei Rhizoma (RR), Scutellariae Radix (SR) and Coptidis Rhizoma (CR). RR and SR are abundant in anthraquinone and flavonoid polyphenols. Pharmacokinetic study of SHXXT indicated that glucuronides were the predominant forms of polyphenols in rats.

MATERIALS AND METHODS

As an extension of pharmacokinetic study, the serum metabolites of SHXXT, RR, SR and CR were prepared from rats and quantitated, then the immunomodulation effects were examined by culturing these serum metabolites with murine and human immune cells.

RESULTS

The results indicated that the inhibitions on nitric oxide (NO) and cytokine production from mitogen-activated peritoneal macrophages by the serum metabolites of SHXXT, RR, SR and CR were through reducing the protein expression of inducible NO synthase (iNOS) and the IC(50) were 0.8%, 1.5%, 3.0% and 0.8% of their blood concentrations, respectively. In addition, the serum metabolites of SHXXT, RR, SR and CR significantly decreased the ratios of interferon-gamma (IFN-gamma) to interleukin (IL)-4 in mitogen-stimulated mice spleen cells and human peripheral blood mononuclear cells (PBMCs). Moreover, the serum metabolites of SHXXT and SR significantly arrested the mitogen-stimulated mice spleen cells at G2/M stage.

CONCLUSIONS

In conclusion, the serum metabolites of SHXXT and the component herbs exerted promising modulation activities on the immune functions and the cell cycle distribution of mice and human immune cells. We suggest that SHXXT is a promising remedy for immunomodulation through Th1/Th2 regulation.

Hepatoprotective effects of Coptidis rhizoma aqueous extract on carbon tetrachloride-induced acute liver hepatotoxicity in rats

AIM OF THE STUDY

Coptidis rhizoma (CR, Chinese name is Huanglian) has been used in treating infectious and inflammatory diseases for two thousand years in Traditional Chinese Medicine (TCM). Its related pharmacological basis for the therapeutics has been studied intensively, but CR can also be used for vomiting of "dampness-heat type or acid regurgitation" due to "liver-fire attacking stomach" in TCM, whose symptoms seem to link the hepatic and biliary disorders, yet details in the therapies of liver diseases and underlying mechanism(s) remain unclear. To clarify this ethnopharmacological relevance, hepatoprotective effect of Coptidis rhizoma aqueous extract (CRAE) and its possible mechanism were studied in rats intoxicated with carbon tetrachloride (CCl4) in the present study.

MATERIALS AND METHODS

SPRAGUE-Dawley (SD) rats aged 7 weeks old were intraperitoneally injected with CCl4 at a dose of 1.0 ml/kg as a 50% olive oil solution. The rats were orally given the CRAE at doses of 400, 600, 800 mg/kg and 120 mg/kg berberine body weight (BW) after 6 h of CCl4 treatment. At 24 h after CCl4 injection, samples of blood and liver were collected and then biochemical parameters and histological studies were carried out.

RESULTS

The results showed that CRAE and berberine inhibited significantly the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and increased the activity of superoxide dismutase (SOD). Observation on the hepatoprotective effect of berberine was consistent to that of CRAE.

CONCLUSION

The study is the first time to demonstrate that CRAE has hepatoprotective effect on acute liver injuries induced by CCl4, and the results suggest that the effect of CRAE against CCl4-induced liver damage is related to antioxidant property.

Pharmacokinetics of anthraquinones in Xiexin decoction and in different combinations of its constituent herbs

Xiexin decoction (XXD), a classic pyretolysis formula, is composed of Rhei Rhizoma (DH), Radix Scutellaria (HQ) and Coptis Chinensis (HL) and is commonly used in the clinical setting. The aim of this study was to investigate the pharmacokinetic differences of the five anthraquinones in rats after oral administration of XXD and different combinations of its constituent herbs. Twenty rats were randomly divided into four groups and were administered one of the four extracts: DH, DH-HQ, DH-HL and XXD (DH-HQ-HL) via intragastric gavage. Anthraquinone concentrations in plasma were determined by an HPLC technique. Pharmacokinetic parameters were calculated from the plasma concentration-time data. Compared with DH alone, the DH-HL combination decreased C(max) of all five anthraquinones and AUC of four anthraquinones (except physcion), and the DH-HQ combination decreased AUC of aloe-emodin and C(max) of rhein. Finally, XXD increased AUC of all five anthraquinones compared with DH-HL combination. These results showed that the oral bioavailabilities of five anthraquinones were decreased significantly by combining DH with HL, whereas HQ weakened the effect of HL that inhibited the absorption of anthraquinones.

Bear bile: dilemma of traditional medicinal use and animal protection

Bear bile has been used in Traditional Chinese Medicine (TCM) for thousands of years. Modern investigations showed that it has a wide range of pharmacological actions with little toxicological side effect and the pure compounds have been used for curing hepatic and biliary disorders for decades. However, extensive consumption of bear bile made bears endangered species. In the 1980's, bear farming was established in China to extract bear bile from living bears with "Free-dripping Fistula Technique". Bear farming is extremely inhumane and many bears died of illness such as chronic infections and liver cancer. Efforts are now given by non-governmental organizations, mass media and Chinese government to end bear farming ultimately. At the same time, systematic research has to be done to find an alternative for bear bile. In this review, we focused on the literature, laboratory and clinical results related to bear bile and its substitutes or alternative in English and Chinese databases. We examined the substitutes or alternative of bear bile from three aspects: pure compounds derived from bear bile, biles from other animals and herbs from TCM. We then discussed the strategy for stopping the trading of bear bile and issues of bear bile related to potential alternative candidates, existing problems in alternative research and work to be done in the future.

Effects of San-Huang-Xie-Xin-Tang on U46619-induced increase in pulmonary arterial blood pressure

ETHNOPHARMACOLOGICAL RELEVANCE

San-Huang-Xie-Xin-Tang (SHXT), composed of Coptidis rhizoma, Scutellariae radix and Rhei rhizoma, is traditionally used to treat hypertension.

AIM OF THE STUDY

Our aim was to investigate the pharmacology effect of SHXT on a thromboxane A(2) analogue U46619-induced increase in pulmonary hypertension and protein expression in primary pulmonary smooth muscle cells (PASMCs).

MATERIALS AND METHODS

Arterial blood pressure and isometric tension in the aorta and pulmonary artery of rats were measured by pressure and force transducers, respectively. Protein expressions on PASMCs were detected by Western blotting.

RESULTS

SHXT significantly attenuated U46619-induced increase in arterial blood pressure. The inhibitory effect of SHXT on pulmonary arterial pressure was greater than systemic arterial pressure in U46619 treated rats. Similarly, the inhibitory effect of SHXT on U46619-induced vasoconstriction in rat pulmonary arterial rings was greater than that in aortic rings. In U46619 treated PASMCs, SHXT down-regulated expression of phosphodiesterase type 5 (PDE5), Rho-kinase (ROCK) II, cyclooxygenase-2 (COX-2) and up-regulated expression of soluble guanylyl cyclase (sGC) alpha(1) and sGCbeta(1).

CONCLUSIONS

SHXT attenuated U46619-induced increase in systemic and pulmonary arterial blood pressure. Inhibition of PDE5, ROCK-II, COX-2 and stimulation of sGC may play important roles in the cardiovascular effects of SHXT.

Simultaneous quantification of twelve bioactive components in San-huang-xie-xin-tang by HPLC

A simple and reliable high-performance liquid chromatographic method with ultraviolet detection (280 nm) has been developed for the simultaneous analysis of 12 bioactive components in San-huang-xie-xin-tang (SHXXT), a traditional Chinese medicine containing Rhei rhizome, Coptidis rhizome and Scutellariae radix. A relatively simple extraction procedure was employed and optimised, and separation of the components was obtained within 1 h using a reversed-phase column under gradient elution with acetonitrile and a buffer containing 0.01 M sodium 1-pentanesulphonate (pH 3). The lower limit of detection for the analytes ranged from 25 to 75 ng/mL. The correlation coefficients associated with each calibration curve were greater than 0.99. The precision and accuracy of the method ranged from 1.0 to 10.5% at low concentration levels, 0.8 to 8.7% at medium levels and 1.2 to 5.8% at high levels. In commercial products of SHXXT, baicalin and berberine were present in the highest amounts with levels up to 4.0 and 3.3%, respectively, in one sample. The HPLC method was able rapidly and efficiently to analyse constituents in crude herb and traditional Chinese medicinal preparations containing Rhei rhizome, Coptidis rhizome and Scutellariae radix.

Effect of Scutellariae Radix Extract on the High Glucose-Induced Apoptosis in Cultured Vascular Endothelial Cells

Endothelial cell apoptosis has been postulated as the initial trigger of the progression of microvascular disease in patients with diabetes mellitus. To investigate the role of Scutellariae radix extract, we examined its effect on the endothelial cell proliferation using the [3H]-thymidine incorporation method. Scutellariae radix extract significantly stimulated endothelial cell proliferation in a dose-dependent manner. We focused on the protective action of Scutellariae radix extract on the endothelial cell apoptosis induced by high glucose concentrations. Determination of endothelial cell apoptosis was performed using DNA gel electrophoresis, terminal deoxynuclotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, and an ELISA kit. Exposure of vascular endothelial cell to high glucose (16.7 mM) for 72 h resulted in a significant increase in apoptosis, compared with the normal glucose concentrations (5.5 mM). Scutellariae radix extract inhibited high glucose-induced endothelial cell apoptosis. This result suggests that Scutellariae radix extract may contribute to antiapoptotic action against vascular endothelial cells, resulting in a beneficial effect in preventing diabetes-associated microvascular complications.