[Pharmacological studies on schizandra fruits. II. Effects of constituents of shizandra fruits on drugs induced hepatic damage in rats]

Gomisin M2 Ameliorates Atopic Dermatitis-like Skin Lesions via Inhibition of STAT1 and NF-κB Activation in 2,4-Dinitrochlorobenzene/Dermatophagoides farinae Extract-Induced BALB/c Mice

The extracts of Schisandra chinensis (Turcz.) Baill. (Schisandraceae) have various therapeutic effects, including inflammation and allergy. In this study, gomisin M2 (GM2) was isolated from S. chinensis and its beneficial effects were assessed against atopic dermatitis (AD). We evaluated the therapeutic effects of GM2 on 2,4-dinitrochlorobenzene (DNCB) and Dermatophagoides farinae extract (DFE)-induced AD-like skin lesions with BALB/c mice ears and within the tumor necrosis factor (TNF)-α and interferon (IFN)-γ-stimulated keratinocytes. The oral administration of GM2 resulted in reduced epidermal and dermal thickness, infiltration of tissue eosinophils, mast cells, and helper T cells in AD-like lesions. GM2 suppressed the expression of IL-1β, IL-4, IL-5, IL-6, IL-12a, and TSLP in ear tissue and the expression of IFN-γ, IL-4, and IL-17A in auricular lymph nodes. GM2 also inhibited STAT1 and NF-κB phosphorylation in DNCB/DFE-induced AD-like lesions. The oral administration of GM2 reduced levels of IgE (DFE-specific and total) and IgG2a in the mice sera, as well as protein levels of IL-4, IL-6, and TSLP in ear tissues. In TNF-α/IFN-γ-stimulated keratinocytes, GM2 significantly inhibited IL-1β, IL-6, CXCL8, and CCL22 through the suppression of STAT1 phosphorylation and the nuclear translocation of NF-κB. Taken together, these results indicate that GM2 is a biologically active compound that exhibits inhibitory effects on skin inflammation and suggests that GM2 might serve as a remedy in inflammatory skin diseases, specifically on AD.

Study on the pharmacokinetics of deoxyschizandrin and schizandrin in combination with epigallocatechin gallate, a component of green tea, in rats

1. Green tea is commonly used worldwide due to its potential positive health benefits. We have examined the effects of epigallocatechin gallate (EGCG), the most abundant catechin in green tea, on the pharmacokinetics of deoxyschizandrin (DSD) and schizandrin (SD), which are the representative lignans in popular traditional Chinese medicines Fructus schisandrae, in rats. 2. The effects on the transport in Caco-2 cells and metabolism in human liver microsomes (HLMs) of DSD and SD by EGCG were determined to analyze their interactions thoroughly. 3. In pharmacokinetic studies, rats were divided into four groups. Each group was orally treated with DSD alone (Group 1), DSD combined with EGCG (Group 2), SD alone (Group 3) and SD combined with EGCG (Group 4). The pharmacokinetic parameters of DSD and SD in rats were determined by UPLC-MS/MS. 4. The in vivo results indicated that EGCG had no significant influence on the pharmacokinetic behaviors of DSD or SD in rats, which were in accordance with the in vitro transport and metabolism studies. However, there were marked differences between male and female rats among C_max, AUC_0-t, AUC_0-∞ of DSD and SD. This disparity suggested that gender differences might exist in the pharmacokinetic processes of DSD or SD in rats.

Deoxyschizandrin suppresses dss-induced ulcerative colitis in mice

BACKGROUND/AIMS

Deoxyschizandrin as one of the most important component of Schisandra chinensis (Turcz.) Baill plays an immunomodulatory role in a variety of diseases, yet its role in ulcerative colitis remains to be elucidated. We aimed to investigate the role of deoxyschizandrin in DSS-induced ulcerative colitis in mice.

PATIENTS AND METHODS

In the present study, an inflammation model of cells was constructed to confirm the anti-inflammatory effect of deoxyschizandrin. Then a mouse model with Dextran sulfate sodium sulfate (DSS)-induced ulcerative colitis was constructed, and the effects of deoxyschizandrin on mouse colon inflammation, apoptosis, and CD4 T lymphocyte infiltration in ulcerative colitis were examined.

RESULT

Deoxyschizandrin could improve the symptoms of ulcerative colitis, determined by hematoxylin-eosin (HE) staining and histopathological scores. Moreover, deoxyschizandrin reduced the levels of inflammatory cytokines, suppressed CD4 T cell infiltration, and effectively inhibited apoptosis in the colon of DSS-induced ulcerative colitis mice.

CONCLUSION

In summary, deoxyschizandrin can effectively rescue the symptoms of DSS-induced ulcerative colitis in mice by inhibiting inflammation. T cell infiltration and apoptosis in the colon, suggesting that deoxyschizandrin could be a potential drug in treating ulcerative colitis.

Small scale rat hepatocyte primary culture with applications for screening hepatoprotective substances

Isolated hepatocytes are known to maintain their physiological functions for over a week when cultured on Matrigel, artificially reconstituted from basement membrane components. Although this culture technique has been frequently used in research on hepatocyte functions, there has been a limitation on its application for small scale experiments due to some technical problems. By using micro-culture plates with 96 round-bottom wells, we succeeded in coating the wells uniformly with Matrigel. When the cultured hepatocytes were treated with either 10 mM, 15 mM, or 20 mM of acetaminophen or 1 mM, 10 mM, or 20 mM of D-galactosamine, the viability of the hepatocytes became 91.1%, 75.3%, 64.7%, and 79.0%, 43.8%, 26.2% of the non-treated control at 48 hours, respectively. Fractionated extracts of Glycyrrhiza glabra L. and Schisandra chinensis Baillon inhibited the action of acetaminophen or D-galactosamine in this model. From these results, we concluded that the microculture system presented here is capable of maintaining the in vivo characteristics of hepatocytes and is suitable for the screening of hepatoprotective substances.

Effect of biphenyl dimethyl dicarboxylate on the cellular and nonspecific immunosuppressions by ketoconazole in mice

The effect of biphenyl dimethyl dicarboxylate (PMC) on the cellular and nonspecific immunosuppressions by ketoconazole (KCZ) was investigated in ICR mice. PMC at a dose of 6 mg/kg was administered orally to mice daily for 14 consecutive days. KCZ was suspended in RPMI 1640 medium and orally administered at 160 mg/kg/day 2 hrs after the administration of PMC. Immune responses of the delayed-type hypersensitivity (DTH) reaction to sheep red blood cells (SRBC), phagocytic activity and natural killer (NK) cell activity were evaluated. DTH reaction to SRBC was enhanced to normal level by the combination of PMC and KCZ, compared with treatment of KCZ alone. In the combination of PMC and KCZ, as compared with the treatment of KCZ alone, there were also significant increases in activities of natural killer (NK) cells and phagocytes along with circulating leukocytes. These findings indicate that PMC shows a significant restoration from the immunotoxic status induced by KCZ.

Effect of biphenyl dimethyl dicarboxylate on the humoral immunosuppression by ketoconazole in mice

The present study was undertaken to investigate the effect of biphenyl dimethyl dicarboxylate (PMC) on the humoral immunosuppression by ketoconazole (KCZ) in ICR mice. PMC at a dose of 6 mg/kg was administered orally to mice daily for 14 consecutive days. KCZ was suspended in RPMI 1640 medium and orally administered at 160 mg/kg/day 2 hrs after the administration of PMC. Mice were immunized and challenged with sheep red blood cells (SRBC). The results of the present study are summarized as follows; a gain of body weight and relative weights of spleen and liver were significantly increased by combination of PMC and KCZ, as compared with those in mice treated with KCZ alone. Splenic plaque forming cells (PFC) and hemagglutination (HA) titers to SRBC were greatly enhanced by the combination of PMC and KCZ, compared with treatment of KCZ alone. The elevation of serum glutamicpyruvic transaminase (S-GPT) and total protein levels caused by KCZ were reduced to normal level by the combination of PMC and KCZ. In addition, lower serum albumin and A/G ratio were also increased to normal level. These findings indicate that PMC has a protective effect against KCZ-induced humoral immunosuppression.

Inhibitory effect of gomisi on reductive metabolism of halothane

The effect of Gomisi (dried ripe fruit of schizandra chinensis) on chlorodifluoroethylene (CDE) and chlorotrifluoroethane (CTE) formation was investigated. The incubation mixtures for the measurement of reductive metabolites of halothane consisted of liver microsomal suspensions, 3 mM NADPH, extract solution of Gomisi and halothane in 0.1 M potassium phosphate buffer (pH 7.4). The production of CDE and CTE was inhibited by Gomisi in a dose-dependent way. The production were reduced to half in the presence of 0.5% Gomisi extract in the reaction mixture. The results suggest that Gomisi can inhibit the reductive metabolism of halothane in vitro; thus it may protect against halothane-induced hepatitis.

Effects of gomisin A on hepatocarcinogenesis by 3'-methyl-4-dimethylaminoazobenzene in rats

We examined the effects of gomisin A on tumor promotion in the liver after a short-term feeding of 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB) to rats, compared with the effects of phenobarbital. Male Donryu rats were fed ad libitum a diet containing 0.06% 3'-MeDAB and 0.03% or 0.01% gomisin A or water containing 0.05% phenobarbital. Gomisin A and phenobarbital did not cause any proliferative and neoplastic lesions by themselves in 40 weeks of feeding. Altered foci in the liver increased with a peak at 12 weeks after the rats were fed 3'-MeDAB. Gomisin A decreased the number of hepatic altered foci such as the clear cell and basophilic cell type foci in the early stages. Phenobarbital enhanced neoplastic alterations so that the number and size of the foci were much larger in the phenobarbital-combined group than in the 3'-MeDAB-control group. Thus, phenobarbital acted as a promoter of cells initiated by 3'-MeDAB; on the other hand, gomisin A showed a weak suppressive effect on tumor promotion.

Inhibitory effect of TJN-101 ((+)-(6S,7S,R-biar)-5,6,7,8-tetrahydro-1,2,3,12-tetramethoxy -6,7-dimethyl-10,11- methylenedioxy-6-dibenzo[a,c]cyclooctenol) on immunologically induced liver injuries

TJN-101, which is a lignan component isolated from schisandra fruits, inhibits hepatotoxic chemicals-induced liver injuries. In this study, effects of TJN-101 on immunologically induced liver injuries were investigated in vivo and in vitro. When a small dose of lipopolysaccharide was injected into mice previously injected with heat-killed Propionibacterium acnes, most of the animals died with acute hepatic failure which was produced by cytotoxic factors from activated adherent cells, and liver cells were injured by antibody-dependent cell-mediated cytotoxic (ADCC) reaction or activated macrophages in vitro. TJN-101 reduced the mortality of the mice with acute hepatic failure dose-dependently. Histologically, necrosis was suppressed by the treatment of TJN-101, but infiltration of non-specific inflammatory cells was not. TJN-101 inhibited the isolated liver cell injuries induced by ADCC reaction or activated macrophages in vitro. These results suggest that TJN-101 can be markedly protective against immunological liver injuries.

Effects of gomisin A on liver functions in hepatotoxic chemicals-treated rats

The effects of gomisin A, which is a lignan component of schizandra fruits, on liver functions in various experimental liver injuries and on bile secretion in CCl4-induced liver injury were studied. Gomisin A weakly accelerated the disappearance of plasma ICG by itself at a high dose (100 mg/kg, i.p.). All of the hepatotoxic chemicals used in this study inhibited the excretion of ICG from plasma. Gomisin A showed a tendency to prevent the delays of the disappearance of plasma ICG induced by CCl4, d-galactosamine and orotic acid, but not that by ANIT. Bile flow and biliary outputs of total bile acids and electrolytes (Na+, K+, Cl- and HCO3-) were decreased in CCl4-treated rats. Gomisin A maintained bile flow and biliary output of each electrolyte nearly to the level of the vehicle-treated group, but did not affect biliary output of total bile acids. These findings suggest that gomisin A possesses a liver function-facilitating property in normal and liver injured rats and that its preventive action on CCl4-induced cholestasis is due to maintaining the function of the bile acids-independent fraction.