Antioxidative effects of Choi-oki-to and its ability to inhibit the progression of atheroma in KHC rabbits

Effects of oral administration of tripeptides derived from type I collagen (collagen tripeptide) on atherosclerosis development in hypercholesterolemic rabbits

Digestion of type I collagen with a collagenase-type protease yields a collagen tripeptide (Ctp) fraction comprising Gly-X-Y sequences that exhibit diverse biological activities. We previously demonstrated that Ctp inhibits the proliferation and migration of cultured aortic smooth muscle cells (SMCs) in vitro. These cells contribute to the pathogenesis of atherosclerosis and other cardiovascular diseases. In order to evaluate the effects of Ctp on atherosclerosis development in vivo, here we used the Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbit model of familial hypercholesterolemia to determine the effects of oral administration of Ctp for three months. Ctp induced a significant decrease in the area occupied by atherosclerotic plaques in the aorta and in the level of total serum cholesterol. The components of atherosclerotic plaques underwent distinct changes, including reduction in the populations of macrophages and SMCs and a significant decrease in the proportion of macrophages to SMCs. Ctp administration decreased the number of cells in plaques that expressed proliferating cell nuclear antigen and the number of cells with oxidative damage to DNA as indicated by 8-hydroxy-2'-deoxyguanine detection. These findings are the first to define the mechanism underlying the inhibitory effects of Ctp on atherosclerosis development in hypercholesterolemic rabbits, and suggest that Ctp provides an effective therapy for treating atherosclerosis.

Japanese herbal medicines shosaikoto, inchinkoto, and juzentaihoto inhibit high-fat diet-induced nonalcoholic steatohepatitis in db/db mice

Few studies have investigated the effects of Japanese herbal medicines on nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). To the best of our knowledge, only one study has examined whether high-fat (HF) diet-fed db/db mice are appropriate animal models of NASH. We investigated the effects of four types of Japanese herbal medicines (shosaikoto (TJ-9), inchinkoto (TJ-135), juzentaihoto (TJ-48), and keishibukuryogan (TJ-25)) on hepatic lesions of HF diet-fed db/db mice. Db/db mice were divided into six groups: control diet (control); HF diet (HF); and HF diet supplemented with TJ-9, TJ-135, TJ-48, or TJ-25 (TJ-9, TJ-135, TJ-48, and TJ-25, respectively). Mice were killed after 6 weeks of treatment, and biochemical and pathological analyses were performed. Mice in the HF group consistently developed histopathological features consistent with definite NASH, and marked necroinflammation occurred. Serum alanine aminotransferase levels in the TJ-9, TJ-135, and TJ-48 groups were significantly improved compared with those in the HF group. With regard to liver histology, TJ-9 and TJ-48 significantly improved lobular inflammation, and TJ-135 significantly improved ballooning degeneration. We have shown that HF diet-fed db/db mice are animal models that correctly recapitulate the histopathology of human NASH and that TJ-9, TJ-135, and TJ-48 inhibit necroinflammatory activity in this model.

Identification of licopyranocoumarin and glycyrurol from herbal medicines as neuroprotective compounds for Parkinson's disease

In the course of screening for the anti-Parkinsonian drugs from a library of traditional herbal medicines, we found that the extracts of choi-joki-to and daio-kanzo-to protected cells from MPP⁺-induced cell death. Because choi-joki-to and daio-kanzo-to commonly contain the genus Glycyrrhiza, we isolated licopyranocoumarin (LPC) and glycyrurol (GCR) as potent neuroprotective principals from Glycyrrhiza. LPC and GCR markedly blocked MPP⁺-induced neuronal PC12D cell death and disappearance of mitochondrial membrane potential, which were mediated by JNK. LPC and GCR inhibited MPP⁺-induced JNK activation through the suppression of reactive oxygen species (ROS) generation, thereby inhibiting MPP⁺-induced neuronal PC12D cell death. These results indicated that LPC and GCR derived from choi-joki-to and daio-kanzo-to would be promising drug leads for PD treatment in the future.

Inhibitory effects of Japanese herbal medicines sho-saiko-to and juzen-taiho-to on nonalcoholic steatohepatitis in mice

Although Japanese herbal medicines (JHMs) are widely used in Japan, only a few studies have investigated their effects on nonalcoholic steatohepatitis (NASH). In the present study, we examined the effect of 4 kinds of JHMs [sho-saiko-to (TJ-9), inchin-ko-to (TJ-135), juzen-taiho-to (TJ-48), and keishi-bukuryo-gan (TJ-25)] on a mouse model of NASH. Db/db mice were divided into 6 groups: control diet (control), methionine- and choline-deficient diet (MCD), and MCD diet supplemented with TJ-9, TJ-135, TJ-48, and TJ-25 (TJ-9, TJ-135, TJ-48, and TJ-25, respectively). All mice were sacrificed after 4 weeks of treatment, and biochemical, pathological, and molecular analyses were performed. Serum alanine aminotransferase levels and liver histology, including necroinflammation and fibrosis, were significantly alleviated in the TJ-9 and TJ-48 groups compared with the MCD group. The expression level of transforming growth factor (TGF)-β1 mRNA in the liver was significantly suppressed by TJ-48. Although the differences were not statistically significant, the expression levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 were lower, and those of peroxisome proliferators-activated receptor (PPAR)γ were higher in the TJ-9 and/or TJ-48 groups than in the MCD group. Similarly, even though the results were not statistically significant, malondialdehyde levels in liver tissues were lower in the TJ-9 and TJ-48 groups than in the MCD group. We showed that JHMs, especially TJ-9 and TJ-48, inhibited the necroinflammation and fibrosis in the liver of a mouse model of NASH, even though the mechanisms were not fully elucidated. Further studies are needed in the future to investigate the possibility of clinical application of these medicines in the treatment for NASH.

Evaluation of oxygen radical absorbance capacity in kampo medicine

Antioxidant capacity of food has come to be shown in terms of oxygen radical absorbance capacity (ORAC) mainly on vegetables or fruit. However, the evaluation of Kampo in terms of ORAC has not yet been accomplished. It is important that such an investigation is also conducted for Kampo medicine. We measured the ORAC value of almost all the available Kampo formulas used in the Japanese National health insurance system and examined the ORAC value both for the daily prescription, and also the crude herb ingredients. The ORAC value of Kampo medicine ranged 4.65–5913 units/day. The ORAC value was high in Kampo formulas including Rhei Rhizoma, and was relatively high in Kampo formulas including anti-inflammatory herbs other than Rhei Rhizoma. The ORAC value was also high in Kampo formulas including crude herbs that have relaxation effects. The ORAC value of a crude herb would seem to not be fixed but be dependent on combination with other crude herbs from the comparison of different herbs added to the basic Kampo medicine. These results suggest variability and complexity of the antioxidant capacity of Kampo medicine within the similar range of food. On the other hand, investigation of the compound changes of various crude herbs with ORAC may lead to the elucidation of the action mechanism of Kampo medicine.

Antioxidative potentiality of a Kampo formulation measured by an ex vivo study

OBJECTIVES

Antioxidants in herbs or crude herbal formulations are well known. The antioxidative effect of a Kampo formulation, Bofu-tsusho-san (BTS), was studied in healthy human subjects by means of an ex vivo study of the lag time of low-density lipoprotein (LDL) oxidation.

METHODS

Eighteen (18) healthy young males (22 +/- 3 years old), who were screened out from 38 males by strict screening tests of serum lipids, were randomly assigned into 3 groups (active BTS 7.5 g/day, placebo of BTS 7.5 g/day, and vitamin E 500 mg and vitamin C 1000 mg/day). The BTS groups were assigned in a double-blind manner. These 3 groups took each test drug, and the antioxidant effects of their plasma were estimated by assessing the susceptibility of LDL to oxidation induced by 2-2'-azobis (4-methoxy-2,4-dimethyl-valeronitrile) via an ex vivo study. The antioxidative activity was evaluated by measuring the lag time of the production of conjugated dienes. Along with lag time, plasma ephedrine, plasma baicalin, serum lipid peroxide, serum free fatty acids (nonesterified fatty acids), urinary 8(OH)dG/creatinine, blood pressure, and heart rate were monitored for 24 hours.

RESULTS

Although lag time of the placebo group revealed no significant changes, the active BTS group showed some tendency of prolonged plasma lag time (p = 0.08). However, urinary 8(OH)dG/creatinine and serum lipid peroxide did not show no significant changes. The physiologic changes were compatible with the pharmacokinetic results of ephedrine and its sympathomimetic effect in the active BTS group.

CONCLUSIONS

Although the systemic antioxidative effects of BTS have not been ascertained, the antioxidative potentiality on LDL oxidation was suggested by the ex vivo study.

Suppressive effects of cacao liquor polyphenols (CLP) on LDL oxidation and the development of atherosclerosis in Kurosawa and Kusanagi-hypercholesterolemic rabbits

We investigated the properties of cacao liquor polyphenols (CLP), which have an antioxidative effect on low-density lipoprotein (LDL) and an anti-atherosclerotic effect in the spontaneous familial hypercholesterolemic model, the Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbit. After 6 months of dietary administration of CLP at 1% (w/w) to the KHC rabbits, a higher total cholesterol concentration was observed in the treatment group compared to the control group. However, no other effects were noted in lipid profiles in plasma or lipoproteins. The plasma concentration of thiobarbituric acid reactive substances (TBARS), which is a lipid-peroxidation index, was significantly decreased 1 month after the start of CLP administration compared to that of the control group. The antioxidative effect of CLP on LDL was observed from 2 to 4 months of administration. The area of atherosclerotic lesions in the aorta in the CLP group (32.01+/-1.58%) was significantly smaller than that in the control group (47.05+/-3.29%), and the tissue cholesterol and TBARS concentrations were lower in the CLP group than in the control group. The anti-atherosclerotic effect of CLP was confirmed both rheologically and histopathologically. An in vitro study using KHC rabbit-derived LDL revealed that CLP significantly prolonged the lag time of LDL oxidation that was induced by a lipophilic azo-radical initiator, 2,2'-azobis(4-methoxy)-2,4-dimethylvaleronitrile (V-70), or Cu(2+) from a low concentration of 0.1 microg/mL. The antioxidative effect of CLP was superior to those of the well-known antioxidative substances, vitamin C, vitamin E and probucol. Therefore, CLP suppressed the generation of atherosclerosis, and its antioxidative effect appeared to have an important role in its anti-atherosclerotic activity.

Suppressive Effect of Cocoa Powder on Atherosclerosis in Kurosawa and Kusanagi-hypercholesterolemic Rabbits

We investigated the suppressive effect of cocoa powder (cacao polyphenol content: 7.8%) on atherosclerosis in a spontaneous familial hypercholesterolemic model, Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits. Six-month dietary administration of cocoa powder had no effects on body weight, hematology or blood chemistry parameters or a lipid profile in KHC rabbits. Antioxidative activity of low-density lipoprotein (LDL) was observed in the 2nd month and 3rd month of administration. Thiobarbituric acid reactive substances (TBARS), the marker of lipid peroxidation, in plasma were decreased in the cocoa powder treated group from the 2nd month of administration during the study period compared to that in the control group. The area of atherosclerotic lesions in th aorta was significantly smaller in the cocoa powder group (30.87%) than in the control (52.39%). Tissue cholesterol content also tended to decrease. Distensibility of the aortic wall was improved significantly in the cocoa powder treated group due to decreases in fatty streaks and intimal thickening compared to that in the control group. These results suggest that cocoa powder has suppressive effect on development of atherosclerotic lesions. We consider that antioxidative activity of polyphenols rich in cocoa powder may be a key factor for the anti-atherosclerotic effect.

Evaluation of Rhubarb using antioxidative activity as an index of pharmacological usefulness

We attempted to estimate the pharmacological activity by measuring the concentrations of a composition ingredient using a multivariate statistical analysis method. Medicinal herb of Rhubarb has been many largely unrecognized biochemical and pharmacological effect components. Therefore, we attempted to estimate the antioxidative activity of Rhubarb on low-density lipoprotein (LDL) of its components. Thirty specimens of Rhubarb from various origins were used, chose nine components of anthraquinones, two components of anthrones, two components of flavan-3-ols, one component of procyanidin, one component of naphthalene, two components of phenylbutanones and one component of stilbene. Quantitative analysis of 18 components was performed with high-performance liquid chromatography (HPLC) and antioxidative activities were measured with plasma taken from spontaneous familial hypercholesterolemia model rabbits. There was considerable variation among the specimens in the concentration of components and antioxidative activities on LDL. As a result of multiple regression analysis, significant multiple correlation coefficient for antioxidative activities on LDL (R=0.914, P<0.01) was found in relation to the concentrations of five components: aloe-emodin, chrysophanol, emodin 1-O-beta-D-glucoside, lindleyin and 6-hydroxymusizin 8-O-beta-D-glucoside. Three of the five components were not active in promoting antioxidative activity and there was no significant correlation between the concentrations of the most active component and the activity. We consider this a useful method for selecting of Rhubarb and propose a new scientific approach for the selection of natural medicines.