Protective effects of taurine against inflammation, apoptosis, and oxidative stress in brain injury.

The protective effect of taurine against inflammation, apoptosis and oxidative stress in traumatic brain injury was investigated in the present study. Taurine is a non­proteogenic and essential amino acid in animals. It plays a critical nutritional role in brain cell growth, differentiation, and development. Taurine is involved in regeneration and neuroprotection in the injured nervous system, and is an effective antioxidant against lead­, cadmium­, and exercise­induced oxidative stress. Astrocytes and neuron cells were co­cultured and cells were treated with different concentrations of taurine (100, 200 and 300 mg/l) for 72 h, and the levels of reactive oxygen species, malondialdehyde, reduced glutathione, glutathione peroxidase, superoxide dismutase, catalase, acetylcholinesterase, tumor necrosis factor­α, interleukin­6, caspase­3, p53, B­cell lymphoma 2 and Bcl­2­associated X protein were determined. These inflammatory, apoptotic, and oxidative stress markers were substantially increased in injured cells, and returned to normal levels following taurine supplementation. Thus, taurine supplementation may be effective against oxidative stress, apoptosis, and inflammation in injured brain cells.

Harpagoside-induced anaphylactic reaction in an IgE-independent manner both in vitro and in vivo.

BACKGROUND: Harpagoside (HAR) is an active component of Scrophularia ningpoensis (SN), which has anti-inflammatory and anti-immune effects. SN is used widely in China to treat various diseases. Recently, SN has been used as a traditional Chinese medicine injection and used clinically. However, allergic responses to these injections are frequently reported. AIM: We examined whether the main component of SN, HAR, is associated with the allergic reaction to SN. METHODS: This study assessed the effects of HAR in mice and mast cell activation to characterize its anaphylactic effects and underlying mechanisms. Mice hindpaw swelling, serum allergy factor detection, enzyme-linked immunosorbent assays, and degranulation assays were performed to measure allergic mediators both in vivo and in vitro. RESULTS: The present study indicated that HAR induced paw swelling, interleukin-6, inositol triphosphate, tumor necrosis factor-α, and histamine increases in mice. Our in vitro data also showed that HAR induced ß-hexosaminidase, inositol triphosphate, and interleukin-6 release, leading to mast cell degranulation. In contrast, neither C48/80 nor HAR induced local anaphylaxis in STOCK KitW-sh/HNihrJaeBsmJNju mice. CONCLUSIONS: HAR is a potential sensitization compound in SN, and these results provide information for the safe clinical use of SN.

Determination of the Environmental Pollution Potential of Some Herbicides by the Assessment of Cytotoxic and Genotoxic Effects on Allium cepa.

The present study aims to evaluate the potential for the pollution of the environment by two herbicides (quizalofop-p-ethyl and cycloxydim), using the Allium test. The species in question is Allium cepa (onion, 2n = 16), one of the most common plant indicators of environmental pollution. The working method consisted of obtaining the meristematic roots of Allium cepa and their treatment with herbicides at three different concentrations (0.5%, 1%, and 1.5%) for each herbicide for 24 h, for comparison with an untreated control. The results obtained from the cytological study indicated a strong cytotoxic and genotoxic effect for both herbicides, but especially for quizalofop-p-ethyl, where the mitotic index decreased from 30.2% (control) to 9.6% for the variant treated with 1.5% herbicide. In this case, a strong mitodepressive effect was shown by a highly significant percentage (35.4%) of chromosomal aberrations and nuclear alterations: stickiness, fragments, C-mitosis, lobulated nucleus, micronuclei, and nuclear erosion. The mitodepressive effect as well as the percentage of chromosomal aberrations increased with a higher herbicide concentration. The obtained results suggest the strong potential for pollution of the two herbicides, particularly at concentrations higher than 0.5%; therefore, we recommend caution in their use to avoid undesirable effects on the environment.

Risk Assessment via Metabolism and Cell Growth Inhibition in a HepG2/C3A Cell Line Upon Treatment with Arpadol and its Active Component Harpagoside.

Harpagophytum procumbens (Hp) has been used as antiinflammatory and analgesic agent for the treatment of rheumatic diseases. The principal active component of Hp is harpagoside (HA). We tested the toxicity of this new therapeutic agent in a hepatic cell line (HepG2/C3A). Hp was found to be cytotoxic, and HA was found to decrease the number of cells in S phase, increase the number of cells in G2/M phase and induce apoptosis. Neither Hp nor HA was genotoxic. The expression of CDK6 and CTP3A4 was reduced by Hp, and both HA and Hp caused a significant reduction of CYP1A2 and CYP3A4 expression. It is possible that the cytotoxicity caused by HA and Hp does not involve transcriptional regulation of the cyclins and CDKs tested but is instead related to the inhibition of metabolism. This is evidenced by the results of an MTT assay and changes in the expression of genes related to drug metabolism, leading to cell death. Indeed, the cells exhibited decreased proliferation upon exposure to Hp and HA. The data show that treatment with either Hp or HA can be cytotoxic, and this should be taken into consideration when balancing the risks and benefits of treatments for rheumatic diseases. Copyright © 2016 John Wiley & Sons, Ltd.

Salinomycin toxicosis in horses.

CASE DESCRIPTION: A 4-month-old American Paint filly was evaluated because of sudden onset of ataxia that progressed to recumbency. Five additional horses from the same and neighboring premises developed signs of poor performance, generalized weakness, ataxia, and recumbency; 2 of those horses were also evaluated. A new batch of a commercial feed supplement had been introduced to the horses' diet on each farm within the preceding 3 days. CLINICAL FINDINGS: Other than recumbency, findings of physical and neurologic examinations of the foal were unremarkable. The other 2 horses had generalized weakness and mild ataxia, and 1 horse also had persistent tachycardia. The foal had mild leukocytosis with neutrophilia, hyperglycemia, and mildly high serum creatine kinase activity. Results of cervical radiography, CSF analysis, and assessments of heavy metals and selenium concentrations in blood and vitamin E concentration in serum were within reference limits. Feed analysis revealed high concentrations of the ionophore antimicrobial salinomycin. TREATMENT AND OUTCOME: The 5 affected horses survived, but the foal was euthanized. At necropsy, a major histopathologic finding was severe vacuolation within neurons of the dorsal root ganglia, which was compatible with ionophore toxicosis. The surviving horses developed muscle atrophy, persistent weakness, and ataxia. CLINICAL RELEVANCE: In horses, ionophore toxicosis should be considered as a differential diagnosis for acute weakness, ataxia, recumbency, or sudden death. Furthermore, ionophore toxicosis should be considered as a cause of poor performance, weakness, muscle wasting, and cardiac arrhythmias in horses. Surviving horses may have impaired athletic performance.

A 13-week oral dose subchronic toxicity study of gardenia yellow containing geniposide in rats.

Gardenia yellow powders A, B and C, containing geniposide at 0.284%, 0.938% and 2.783%, respectively, were administered orally to male and female SD rats as 3% feed admixtures for 13-weeks to evaluate any potential toxicity. Mean geniposide intake values were 5.72, 18.9 and 56.3mg/kg/day in groups receiving these feed admixtures, respectively. All animals survived the duration of the study. The following findings were evident in the gardenia yellow C group: chromatouria, slightly increased plasma total bilirubin, blackish brown discoloration of the kidneys and liver, brown pigments in the proximal tubular epithelium of the kidneys. Slightly increased plasma total bilirubin was considered to be due to interference of metabolite of geniposide with the system of measurement and not to be a toxic effect since there were no related changes in histopathology of the liver or in any blood chemistry parameters. Other findings were limited to pigmentations or discolorations attributable to metabolites of geniposide. No treatment-related effects were evident on body weight, food consumption, ophthalmology, hematology or organ weights in any group. Therefore, it was concluded that 3-month ingestion of the gardenia yellow powder containing geniposide at 2.783% (approximately 60 mg/kg/day as geniposide intake) does not cause any severe toxic effects.

[Experimental studies on hepatotoxicity of rats induced by Fructus Gardeniae].

OBJECTIVE: To study the hepatotoxicity effects in rats with different extract of Fructus Gardeniae. METHOD: Observe the change of appearance, behavior and weight of rats through oral gavage daily for 3 d. Weigh the liver and calculate the liver index. Detect the ALT, AST and TBIL. Observe the liver tissue by optical microscope. RESULT: The weight and index of liver were increased by 3.08 g x kg(-1) aqueous extract, 1.62 g x kg(-1) alcoholic extract and 0.28 g x kg(-1) geniposide, compared to those of the blank group (P < 0.005, P < 0.001) and the activities of ALT, AST and the content of TBIL were also increased, compared to those of the blank group (P < 0.05, P < 0.001). The liver cells were obviously swell, necrotic and changed with inflammatory infiltrate. CONCLUSION: Aqueous extract, alcoholic extract and geniposide displayed hepatotoxicity, and the geniposide which was the main substance of the Fructus Gardeniae might be mainly responsible for the hepatotoxicity.

Genipin suppression of fibrogenic behaviors of the alpha-TN4 lens epithelial cell line.

PURPOSE: To determine in a lens epithelial cell line, alpha-TN4, whether genipin, an intestinal metabolite component of the herbal medicine inchin-ko-to, suppresses profibrogenic myofibroblast generation and upregulation of fibrogenic cytokines and to evaluate the potential benefit of the medicine in preventing posterior capsule opacification (PCO). SETTING: Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan. METHODS: In this study, alpha-TN4 cell proliferation, migration, and expression of alpha-smooth muscle actin (alpha-SMA), the hallmark of myofibroblast generation, were assayed with a colorimetric assay, scratch wound assay, immunohistochemistry, and Western blot analysis. Gene expression of transforming growth factor-beta1 (TGF-beta1) and connective tissue growth factor (CTGF) was characterized with real-time reverse transcription-polymerase chain reaction. In addition, p38 mitogen-activated protein kinase (p 38 MAPK), extracellular signal-regulated kinase (ERK) limb, and Smad signalings were evaluated by Western blotting and immunohistochemistry. Cytotoxicity of genipin was evaluated using a commercial colorimetric assay kit for nuclear matrix protein 41/7 (NMP41/7) in culture medium. RESULTS: Genipin suppressed cell proliferation and migration in association with inhibition of Smad and p38 MAPK phosphorylation, although ERK signaling was enhanced. Genipin suppressed mRNA expression of TGF-beta1 and CTGF. Cytoplasmic fiber formation declined based on less intense alpha-SMA immunocytochemical staining. However, alpha-SMA protein expression was actually not altered. This negative result suggests that genipin attenuated formation of alpha-SMA-containing cytoskeleton. Treatment of the cells with genipin for 48 hours did not increase the release of NMP41/7 to the medium, indicating this compound is not cytotoxic. CONCLUSION: Because genipin suppressed alpha-TN4 lens cell fibrogenic behaviors, it may be of therapeutic value in preventing PCO.

Biological evaluation of chitosan salts cross-linked to genipin as a cell scaffold for disk tissue engineering.

Degenerative disc disease has been implicated as a major component of spine pathology. However, although biological repair of the degenerate disk would be the ideal treatment, there is no universally accepted scaffold for tissue engineering of the intervertebral disk. To help remedy this, we investigated the gelation kinetics of various concentrations (2.5 to 10%) of two water-soluble chitosan chlorides (low molecular weight Protasan UP CL113 and high molecular weight Protasan UP CL213) and two chitosan glutamates (low molecular weight Protasan UP G113 and high molecular weight Protasan UP G213). Various concentrations (5 to 20%) of genipin, a naturally occurring cross-linking reagent used in herbal medicine and in the fabrication of food dyes, were used to prepare cross-linked chitosan hydrogels. The results show that 2.5% Protasan UP G213 cross-linked to 5% genipin was the best candidate. This formulation gelled fastest at 37 degrees C, and maintained 95% viability of encapsulated cultured disk cells. The gel did not produce an inflammatory reaction when injected subcutaneously into C57BL/6 mice and is therefore biocompatible. Most importantly, when injected into the degenerated nucleus pulposus of human cadaveric intervertebral disk, the gel flowed into the clefts without leakage. This study demonstrates that 2.5% Protasan UP G213 cross-linked to 5% genipin might be a promising scaffold for disk tissue engineering.

Evaluation of zinc against salinomycin toxicity in broilers.

Salinomycin was studied for its toxicity and zinc (80 mg/kg) was assessed for prophylactic and therapeutic management in broiler chicks. Male broiler chicks were randomly divided into 7 groups consisting of 6 chicks in each. Group 1, 2 and 3 were maintained as control, therapeutic dose control (60 mg/kg feed) and toxic dose control (120 mg/kg feed), respectively. Group 4 was fed on feed containing salinomycin therapeutic dose and zinc. Group 5 received feed containing toxic dose of salinomycin. Group 6 and 7 were fed on feed containing toxic dose of salinomycin for the first 4 weeks for induction of ionophore toxicity and for the subsequent 2 weeks, group 6 received zinc and group 7 was fed on feed containing toxic dose of salinomycin along with zinc. Weekly body weights revealed a significant (P<0.01) decrease in toxic controls as compared to group 1, 2, 4 and 5. The activity of glutathione peroxidase, glutathione reductase and catalase, and the values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total proteins, total cholesterol, triglycerides, low density lipoproteins (LDL), urea, creatinine and blood urea nitrogen (BUN) were significantly (P<0.01) elevated in toxic controls, whereas glutathione (GSH) and high density lipoproteins (HDL) were significantly (P<0.01) lowered as compared to group 1, 2, 4 and 5. Following toxicity, zinc supplementation in group 6 and 7, all serobiochemical parameters were revived to normal. Thus, it is enunciated that salinomycin toxicity is due to oxidative damage and use of zinc in feed tends to cure and avoid any accidental toxicity.

Effect of rotenoids from the seeds of Millettia dura on larvae of Aedes aegypti.

A crude chloroform extract of seeds of Millettia dura Dunn (Leguminosae) showed high activity (LC50 = 3.5 microg ml(-1) at 24 h) against second-instar larvae of the mosquito, Aedes aegypti L (Diptera: Culicidae). The rotenoids, deguelin and tephrosin, isolated from the seeds of this plant also showed potent activities, with LC50 values of 1.6 and 1.4 microg ml(-1) at 24 h, respectively. The related rotenoids millettone and millettosin were inactive at 20 microg ml(-1). Saturation at the B/C ring junction and the presence of methoxy groups at C-2 and/or C-3 in deguelin and tephrosin appear to be important for the observed larvicidal activity.

Genotoxicity of gardenia yellow and its components.

Gardenia fruit (Gardenia jasminoides ELLIS) is widely used as a natural food colorant and as a traditional Chinese medicine for treatment of hepatic and inflammatory diseases. "Gardenia yellow" is a natural food colorant which is extracted by ethanol from gardenia fruit. The purpose of this study was to evaluate the genotoxicity of gardenia yellow. Genotoxicity of gardenia yellow and its components, crocetin, gentiobiose (a component of crocin), geniposide and genipin (formed by hydrolysis of geniposide), was studied by Ames test, rec-assay, and sister chromatid exchange (SCE) using V79 cells. Gardenia yellow and its components were found not to be mutagenic in the Salmonella reverse mutation assay. Gardenia yellow and genipin caused damage of DNA in rec-assay. Gardenia yellow induced a significant dose-dependent increase of SCE frequency (8.6 times at 1000 microg/ml as the value for the solvent control). Only genipin induced SCEs significantly among the components of gardenia yellow. Moreover, genipin induced a significant increase of tetraploids at all doses tested (95% at 8 microg/ml). Gardenia yellow preparation was analyzed by capillary electrophoresis (CE), and geniposide was detected. However, genipin was not observed. In conclusion, we have shown that genipin possesses genotoxicity. Furthermore, there were unidentified genotoxicants in gardenia yellow.

Mutagenicity of natural anthraquinones from Rubia tinctorum in the Drosophila wing spot test.

Mutagenicity of anthraquinone aglycones from Rubia tinctorum L. (Rubiaceae) was examined using the somatic mutation and recombination test in Drosophila melanogaster. Larvae heterozygous for recessive wing trichome mutations, multiple wing hairs (mwh), and flare (flr3) were exposed to test compounds and wings of emerged mwh/flr3 females were inspected for the presence of phenotypically mutant mosaic spots. No significant increase in the frequency of mutant spots was observed after the treatment of Drosophila larvae with pure alizarin, xanthopurpurin, and lucidin, or with the crude mixture of anthraquinone aglycones. In contrast, the naphthohydroquinone mollugin induced mainly single spots that can originate either from somatic mutation or from mitotic recombination. Twin spots, consisting of both the mwh and flr3 subclones and originating exclusively from mitotic recombination, were also enhanced, but the increase was only marginally significant. We suggest that mollugin exhibits both the mutagenic and recombinagenic activities.

Constituents and cytotoxicity of Zanthoxylum rhesta stem bark.

3,5-Dimethoxy-4-geranyloxycinnamyl alcohol (1), 8-methoxy-N-methylflindersine (2), xanthyletin and sesamin have been isolated from petroleum ether extract of the stem bark of Zanthoxylum rhesta. The petroleum ether extract and 8-methoxy-N-methylflindersine showed cytotoxicity on brine shrimp nauplii.

Suppressive effect of penta-acetyl geniposide on the development of gamma-glutamyl transpeptidase foci-induced by aflatoxin B(1) in rats.

The suppressive effects of penta-acetyl geniposide, (Ac)(5)-GP, on the hepatotoxic lesions-induced by aflatoxin B(1) (AFB(1)) were investigated in male Wistar rats. Rats were divided into six groups: groups I and II served as normal and solvent control, respectively; group III was given AFB(1) (2 mg/kg body weight) alone; group IV was given (Ac)(5)-GP (2 mg/kg) alone; and groups V and VI received both AFB(1) (2 mg/kg body weight) and (Ac)(5)-GP (1 mg and 2 mg/kg body weight, respectively). Rats received treatments for 8 weeks, then were maintained on basal diet for 32 weeks. At the end of the experiment (week 40), the liver lesions (e.g. fatty change, eosinophilic and bile duct dilation) and preneoplastic changes in rats of groups V and VI were reduced when they were compared with group III. There were no liver lesions and preneoplastic changes in rats treated with (Ac)(5)-GP alone. Although no differences in the total number of gamma-glutamyl transpeptidase (GGT)-positive foci was observed between the groups treated with AFB(1) along with or without (Ac)(5)-GP, the treatment of (Ac)(5)-GP significantly reduced the number of AFB(1)-induced GGT positive foci (with diameter larger than 0.3 mm). These results indicated that the protective effect of (Ac)(5)-GP on early hepatocarcinogenesis-induced by AFB(1) was associated with the inhibition of GGT foci development.

Lack of carcinogenicity of gardenia blue colour given chronically in the diet to F344 rats.

The carcinogenicity of gardenia blue colour was examined in Fischer 344 (F344) rats. Groups of 50 males and 50 females were given the material at dietary doses of 0 (control), 2.5 or 5% for 104 weeks and then sacrificed. The doses were selected on the basis of results from a 13-week subchronic toxicity study. A slight increase in relative organ weights of the left lung was observed in male rats of the 5% group. However, no significant differences between the control and treated groups were noted with regard to clinical signs, mortality and haematological findings. A variety of tumours developed in all groups, including the controls, but all were histologically similar to those known to occur spontaneously in F344 rats, and no statistically significant increase in the incidence of any type of neoplastic lesion was found for either sex in the treated groups. Thus, it was concluded that, under the present experimental conditions, gardenia blue colour is not carcinogenic in F344 rats.

Evaluation of the in-vivo activity and toxicity of amarogentin, an antileishmanial agent, in both liposomal and niosomal forms.

The antileishmanial property of amarogentin, a secoiridoid glycoside isolated from the Indian medicinal plant Swertia chirata, was examined in a hamster model of experimental leishmaniasis. The therapeutic efficacy of amarogentin was evaluated in free and two different vesicular forms, liposomes and niosomes. The amarogentin in both liposomal and niosomal forms was found to be a more active leishmanicidal agent than the free amarogentin; and the niosomal form was found to be more efficacious than the liposomal form at the same membrane microviscosity level. Toxicity studies involving blood pathology, histological staining of tissues and specific enzyme levels related to normal liver function showed no toxicity. Hence, amarogentin incorporated in liposomes or niosomes may have clinical application in the treatment of leishmaniasis.

In vitro evaluation of cytotoxicity of a naturally occurring cross-linking reagent for biological tissue fixation.

A recognized drawback of the currently available chemical cross-linking reagents used to fix bioprostheses is the potential toxic effects a recipient may be exposed to from the fixed tissues and/or the residues. It is, therefore, desirable to provide a cross-linking reagent which is of low cytotoxicity and may form stable and biocompatible cross-linked products. To achieve this goal, a naturally occurring cross-linking reagent -- genipin -- which has been used in herbal medicine and in the fabrication of food dyes, was used by our group to fix biological tissues. The study was to assess the cytotoxicity of genipin in vitro using 3T3 fibroblasts (BALB/3T3 C1A31-1-1). Glutaraldehyde, the most commonly used cross-linking reagent for tissue fixation, was used as a control. The cytotoxicity of the glutaraldehyde- and genipin-fixed tissues and their residues was also evaluated and compared. The observation in the light microscopic examination revealed that the cytotoxicity of genipin was significantly lower than that of glutaraldehyde. Additionally, the results obtained in the MTT assay implied that genipin was about 10000 times less cytotoxic than glutaraldehyde. Moreover, the colony forming assay suggested that the proliferative capacity of cells after exposure to genipin was approximately 5000 times greater than that after exposure to glutaraldehyde. It was noted that the cells seeded on the surface of the glutaraldehyde-fixed tissue were not able to survive. In contrast, the surface of the genipin-fixed tissue was found to be filled with 3T3 fibroblasts. Additionally, neocollagen fibrils made by these fibroblasts were observed on the genipin-fixed tissue. This fact suggested that the cellular compatibility of the genipin-fixed tissue was superior to its glutaraldehyde-fixed counterpart. Also, the residues from the glutaraldehyde-fixed tissue markedly reduced the population of the cultured cells, while those released from the genipin-fixed tissue had no toxic effect on the seeded cells. In conclusion, as far as cytotoxicity is concerned, genipin is a promising cross-linking reagent for biological tissue fixation.

Feasibility study of a natural crosslinking reagent for biological tissue fixation.

Bioprostheses derived from biological tissues must be chemically modified and subsequently sterilized before they can be implanted in humans. Various crosslinking reagents, including formaldehyde, glutaraldehyde, dialdehyde starch, and epoxy compound, have been used to chemically modify biological tissues. However, these synthetic crosslinking reagents are all highly (or relatively highly) cytotoxic. It is therefore desirable to provide a crosslinking reagent suitable for use in biomedical applications that is of low cytotoxicity and that forms stable and biocompatible crosslinked products. This study evaluates the feasibility of using a naturally occurring crosslinking reagent--genipin--to chemically modify biological tissues. Genipin and its related iridoid compounds, extracted from gardenia fruits, have been used in traditional Chinese medicine for the treatments of jaundice and various inflammatory and hepatic diseases. In this feasibility study, the cytotoxicity of genipin and the crosslinking characteristics of genipin-fixed biological tissues were investigated. Fresh porcine pericardia procured from a slaughterhouse were used as raw materials. Glutaraldehyde and an epoxy compound (ethylene glycol diglycidyl ether), which has been used extensively in developing bioprostheses, were used as controls. It was found that the cytotoxicity of genipin was significantly lower than that of glutaraldehyde and the epoxy compound. The amino acid residues in the porcine pericardium that may react with genipin were lysine, hydroxylysine, and arginine. Additionally, the genipin-fixed tissue had a mechanical strength and resistance against enzymatic degradation comparable to the glutaraldehyde-fixed tissue. This suggests that genipin can form stable crosslinked products. The results of this in vitro study demonstrate that genipin is an effective crosslinking reagent for biological tissue fixation.

Modulation of cytochrome P-450-dependent monooxygenases, glutathione and glutathione S-transferase in rat liver by geniposide from Gardenia jasminoides.

Geniposide is an iridoid glycoside extracted from the fruits of Gardenia jasminoides, which are used as a food colorant and as a traditional Chinese medicine for treatment of hepatic and inflammatory diseases. The effects of geniposide and G. jasminoides fruit crude extract on liver cytochrome P-450 (P-450)-dependent monooxygenases, glutathione and glutathione S-transferase were investigated using rats treated orally with the iridoid glycoside (0.1 g/kg body weight/day) or the fruit crude extract (2 g/kg/day) for 4 days. The treatments decreased serum urea nitrogen level but increased liver to body weight ratio, total hepatic glutathione content and hepatic cytosolic glutathione S-transferase activity. Treatments with geniposide and G. jasminoides decreased P-450 content, benzo[a]pyrene hydroxylation, 7-ethoxycoumarin O-deethylation, and erythromycin N-demethylation activities in liver microsomes without affecting aniline hydroxylation activity. The natural products had no effect on glutathione content and monooxygenase activities in kidney microsomes. Immunoblotting analyses of liver microsomal proteins using mouse monoclonal antibody 2-13-1 to rat P4503A1/2 revealed that geniposide and G. jasminoides crude extract decreased the intensity of a P4503A-immunorelated protein. Protein blots probed with mouse monoclonal antibody 1-12-3 to rat P4501A1 and rabbit polyclonal antibody against human P4502E1 showed that both treatments had little or no effect on P4501A and 2E proteins. The present findings demonstrate that geniposide from G. jasminoides has the ability to inhibit a P4503A monooxygenase and increase glutathione content in rat liver.