Suppressive effect of the ethanolic extract of adlay bran on cytochrome P-450 enzymes in rat liver and lungs

Potential herb‒drug interactions between anti-COVID-19 drugs and traditional Chinese medicine

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. Effective treatments against COVID-19 remain urgently in need although vaccination significantly reduces the incidence, hospitalization, and mortality. At present, antiviral drugs including Nirmatrelvir/Ritonavir (PaxlovidTM), Remdesivir, and Molnupiravir have been authorized to treat COVID-19 and become more globally available. On the other hand, traditional Chinese medicine (TCM) has been used for the treatment of epidemic diseases for a long history. Currently, various TCM formulae against COVID-19 such as Qingfei Paidu decoction, Xuanfei Baidu granule, Huashi Baidu granule, Jinhua Qinggan granule, Lianhua Qingwen capsule, and Xuebijing injection have been widely used in clinical practice in China, which may cause potential herb-drug interactions (HDIs) in patients under treatment with antiviral drugs and affect the efficacy and safety of medicines. However, information on potential HDIs between the above anti-COVID-19 drugs and TCM formulae is lacking, and thus this work seeks to summarize and highlight potential HDIs between antiviral drugs and TCM formulae against COVID-19, and especially pharmacokinetic HDIs mediated by metabolizing enzymes and/or transporters. These well-characterized HDIs could provide useful information on clinical concomitant medicine use to maximize clinical outcomes and minimize adverse and toxic effects.

Enhanced Anti-Melanogenic Effect of Adlay Bran Fermented with Lactobacillus brevis MJM60390

Fermentation is a traditional technique used to increase nutrients, flavonoids, vitamins, minerals, and the flavor of raw materials. In this study, adlay bran was fermented by Lactobacillus brevis MJM60390 (FAB), and the anti-melanogenic effect was investigated. The results demonstrated that FAB significantly suppressed melanin accumulation in mouse melanogenic B16F10 cells, and the activity was higher than non-fermented adlay bran (NFAB). The molecular mechanism study showed that FAB inhibited melanin synthesis by suppressing the gene expression of melanocortin 1 receptor (Mc1r), melanocyte-inducing transcription factor (Mitf), tyrosinase (Tyr), tyrosinase-related protein-1 (Trp-1), and tyrosinase-related protein-2 (Trp-2) genes. Western blotting analysis showed that FAB strongly decreased the expression of Tyr, Trp-1, and Trp-2 compared to NFAB. Furthermore, phenolic compounds such as gallic acid, p-coumaric acid, ferulic acid, and sinapic acid, which are known for their anti-melanogenic effects, were significantly increased in FAB compared with NFAB. These findings suggest that FAB holds great potential as an anti-melanogenic agent and can be used for the development of whitening cosmetics.

Natural products in the treatment of pulmonary emphysema: Therapeutic effects and mechanisms of action

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a class of lung diseases including chronic bronchitis, asthma, and emphysema. Long-time smoking is considered the main reason for developing emphysema. Emphysema can be defined as damage to the walls of the air sacs (alveoli) of the lung. It has been demonstrated that natural compounds with antioxidant and anti-inflammatory effects can effectively improve or protect the lung against this disease. This paper is dedicated to systematically review the effective natural compounds in the treatment of pulmonary emphysema.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating pulmonary emphysema STUDY DESIGN AND METHODS: A systematic and comprehensive review was done based on Scopus, PubMed, and Cochrane Library databases were searched using the "emphysema", "plant", "herb", and "phytochemical" keywords. Non-English, review, and repetitive articles were excluded from the study. Search results were included in the Prisma diagram.

RESULTS

From a total of 1285 results, finally, 22 articles were included in the present study. The results show that some herbs such as Scutellaria baicalensis Georgi and Monascus adlay and some phytochemicals such as gallic acid and quercetin and blackboard tree indole alkaloids affect more factors in improving the lung emphysema. Also, some natural compounds such as marijuana smoke and humic acid also play an aggravating role in this disease. It also seems that some of the medicinal plants such as PM014 herbal formula, pomegranate juice and açaí berry sometimes have side effects that are inconsistent with their therapeutic effects.

CONCLUSION

We concluded that natural compounds can effectively improve pulmonary emphysema due to their antioxidant, anti-inflammatory, and anti-apoptotic properties. However, additional studies are suggested to prove efficacy and side effects.

Regulatory Mechanisms of Coicis Semen on Bionetwork of Liver Cancer Based on Network Pharmacology

At present, there is an increasing incidence and mortality of liver cancer. Despite surgery and chemoradiotherapy, there is a lack of effective oral medications with low side effects. In East Asia, Coicis Semen (CS) is used as both food and natural medicine and has a significant impact on the treatment of liver cancer. However, due to its multicomponent and multitarget characteristics, the mechanisms of CS against liver cancer remain unclear. This study collected CS compounds and target proteins in SymMap, then cross-matched with the liver cancer targets in the CTD database to construct an interaction network of CS-liver cancer proteins, and visualized by Cytoscape software. DAVID database was used to perform pathway enrichment analysis to find target proteins in core pathways and the related small molecules in CS. The results showed that a total of 103 common genes shared by CS and liver cancer were obtained, which were enriched for precancerous lesion pathways such as hepatitis B and fatty liver and biological signaling pathways such as HIF-1 and TNF. The combination of sitosterol and CASP3 in CS, acting on “pathways in cancer” and restoring normal cell apoptosis, could be the core mechanisms of CS in the treatment of liver cancer. Based on the system biology analysis, it is speculated that CS may not only participate in multiple mechanisms of action to treat liver cancer synergistically but may also be involved in factors that reduce the incidence of liver cancer.

Food-Drug Interaction between the Adlay Bran Oil and Drugs in Rats

Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) contains various phytonutrients for treating many diseases in Asia. To investigate whether orally administered adlay bran oil (ABO) can cause drug interactions, the effects of ABO on the pharmacokinetics of five cytochrome P450 (CYP) probe drugs were evaluated. Rats were given a single oral dose (2.5 mL/kg BW) of ABO 1 h before administration of a drug cocktail either orally or intravenously, and blood was collected at various time points. A single oral dose of ABO administration did not affect the pharmacokinetics of five probe drugs when given as a drug cocktail intravenously. However, ABO increased plasma theophylline (+28.4%), dextromethorphan (+48.7%), and diltiazem (+46.7%) when co-administered an oral drug cocktail. After 7 days of feeding with an ABO-containing diet, plasma concentrations of theophylline (+45.4%) and chlorzoxazone (+53.6%) were increased after the oral administration of the drug cocktail. The major CYP enzyme activities in the liver and intestinal tract were not affected by ABO treatment. Results from this study indicate that a single oral dose or short-term administration of ABO may increase plasma drug concentrations when ABO is given concomitantly with drugs. ABO is likely to enhance intestinal drug absorption. Therefore, caution is needed to avoid food–drug interactions between ABO and co-administered drugs.

Xinfeng capsule for the treatment of rheumatoid arthritis patients with decreased pulmonary function--a randomized controlled clinical trial

OBJECTIVE

To determine the effectiveness and safety of Xinfeng Capsules (XFC) for the treatment of rheumatoid arthritis (RA) patients with decreased pulmonary function.

METHODS

This was a randomized controlled clinical trial of 80 RA patients. Participants were assigned to the trial group (40 cases) and the control group (40 cases) by block randomization. The trial group was treated with XFC, three pills each time three times daily for 2 months. The control group was treated with tripterygium glycoside (TPT), two pills each time three times daily for 2 months. Both groups were followed up after 2 months. The clinical effects, changes in joint and pulmonary function, and quality of life before and after treatment were observed; safety indices were also evaluated.

RESULTS

Pain, swelling, tenderness, and duration of morning stiffness of joints were obviously decreased after treatment in both the trial and the control groups compared with baseline (P<0.01). Compared with before treatment, hand grip strength increased significantly after treatment in the trial group (P=0.0000); pulmonary function parameters such as forced expiratory volume in the first second of expiration/forced vital capacity (FEV1/FVC), 50% of the expiratory flow of forced vital capacity (FEF50), carbon monoxide diffusing capacity (DLco) were increased (P<0.01 or P<0.05); measures of quality of life such as role-physical, body pain, vitality and mental health were also improved after treatment in the trial group (all P<0.05). Joint swelling in the trial group decreased compared with the control group (P=0.0043), while hand grip strength was increased after treatment (P=0.0000). The increase in FEF50, DLco, and the dimensions of quality of life such as vitality and mental health were all significantly greater in the trial group than the control group (P<0.05 or P<0.01).

CONCLUSIONS

XFC not only relieved joint pain in RA patients, but also significantly improved the ventilation and diffusion function of the lungs. Therefore, XFC could improve the whole body function and enhance the quality of life of RA patients.

Prophylactic Treatment with Adlay Bran Extract Reduces the Risk of Severe Acute Radiation Dermatitis: A Prospective, Randomized, Double-Blind Study

Acute radiation dermatitis is a frequent adverse effect in patients with breast cancer undergoing radiotherapy, but there are only a small number of studies providing evidence-based interventions for this clinical condition. Adlay is a cereal crop that has been previously shown to have anti-inflammatory and antioxidant properties. In this study, we seek to evaluate the effectiveness of oral prophylactic treatment with adlay bran extract in reducing the risk of severe acute radiation dermatitis. A total of 110 patients with breast cancer undergoing radiotherapy were analyzed. Using a prospective, randomized, double-blind design, 73 patients received oral treatment with adlay bran extract and 37 patients received olive oil (placebo). Treatment was started at the beginning of radiation therapy and continued until the termination of radiation treatment. Our results showed that the occurrence of severe acute radiation dermatitis (RTOG grade 2 or higher) was significantly lower in patients treated with oral adlay bran extract compared to placebo (45.2% versus 75.7%, adjusted odds ratio 0.24). No serious adverse effects from adlay bran treatment were noted. In conclusion, prophylactic oral treatment with adlay bran extract reduces the risk of severe acute radiation dermatitis and may have potential use in patients with breast cancer undergoing radiotherapy.

Effect of xinfeng capsule on pulmonary function in a adjuvant arthritis rat model

OBJECTIVE

To observe the relationship between reduced pulmonary function and regulatory T cells (Tregs) and helper T cells (Th)1/Th2 drift in a rat model of adjuvant arthritis (AA), and to study the impact of Xinfeng capsule (XFC) on pulmonary function and investigate the mechanism of action.

METHODS

Forty rats were randomly divided into normal control group (NC), model control group (MC), Tripterygium glycosides tablet group (TPT), and XFC group, with 10 in each. Except for the NC group, AA was induced in all rats by intracutaneous injection of 0.1 mL Freund's complete adjuvant in the right paw. On the 19th day after modeling, the NC and MC groups were given physiological saline (0.9%), while the TPT and XFC groups were given TPT (10 mg/kg) and XFC (2.4 g/kg), once daily, respectively. Thirty days after administration, changes in paw swelling, arthritis index (AI), pulmonary function, levels of serum gamma-interferon (IFN-gamma) and interleukin (IL)-4, Tregs in peripheral blood, and IFN-gamma, IL-4, Forkhead box transcription factor 3 (FoxP3) in lung tissue were observed by enzyme-linked immunosorbent assay, flow cytometry, polymerase chain reaction, and western blot.

RESULTS

Compared with the NC group, paw swelling, AI, IFN-gamma, and Th1/Th2 were increased, and pulmonary function parameters, IL-4, FoxP3 were decreased significantly in the MC group (P < 0.05 or P < 0.01). Pulmonary function parameters, Treg, IL-4, FoxP3 (and mRNA) were higher, and paw swelling, AI, and IFN-gamma (and mRNA) were lower in the XFC group than those in the MC group. The XFC group was also much better than the TPT group in improving pulmonary function, FoxP3 mRNA, IFN-gamma, IL-4, Th1/Th2, and IL-10 (P < 0.05 or P < 0.01).

CONCLUSION

Xinfeng capsule can improve pulmonary function by regulating the levels of Tregs, inhibiting the activation of Th1 to Th2 cells, inducing drift, maintaining cell immune suppression, correcting the imbalance of Th1/Th2, and reducing inflammatory mediators.

In vitro and in vivo studies on adlay-derived seed extracts: phenolic profiles, antioxidant activities, serum uric acid suppression, and xanthine oxidase inhibitory effects

This study aimed to explore the potential of polished adlay, brown adlay, adlay bran, and adlay hull to prevent and treat hyperuricemia. Brown adlay extract effectively decreased the serum uric acid levels of oxonate-induced hyperuricemic rats. Free and bound phenolic extracts from these materials contained significant amounts of phenolics, with free phenolics dominated by chlorogenic acid and p-coumaric acid while bound phenolics dominated by p-coumaric acid and ferulic acid. Free and bound phenolics of adlay bran exhibited significant xanthine oxidase inhibition activities, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, oxygen radical absorbance capacities, and superoxide radical scavenging activities. Adlay bran phenolics could be effective xanthine oxidase inhibitors and radical scavengers. p-Coumaric acid is a xanthine oxidase inhibitor with strong superoxide radical scavenging activity. However, ferulic acid is a xanthine oxidase inhibitor with weak superoxide radical scavenging activity. Chlorogenic acid is a superoxide radical scavenger with weak xanthine oxidase inhibitory activity.

Adlay ( yì yĭ; "soft-shelled job's tears"; the seeds of Coix lachryma-jobi L. var. ma-yuen Stapf) is a Potential Cancer Chemopreventive Agent toward Multistage Carcinogenesis Processes

Adlay ( yì yĭ "soft-shelled job's tears", the seeds of Coix lachryma-jobi L. var. ma-yuen Stapf) is a grass crop that has long been used in traditional Chinese medicine (TCM) and as a nourishing food in China for the treatment of warts, chapped skin, rheumatism, neuralgia, inflammatory, and neoplastic diseases. In addition, adlay also has been said to have stomachic, diuretic, antipholgistic, anodynic, and antispasmodic effects. Carcinogenesis is a multistage process that begins with exposure of viruses or chemicals that are found in the environment. Chemoprevention refers to the use of natural or synthetic, non-toxic chemical substances to reverse, repress, or prevent carcinogenesis. In this review, we summarize recent research attempting to study the chemopreventive blocking and suppressing potential of adlay and its active components in scavenging electrophiles and reactive oxygen species, antimutagenicity, enhancing Nrf2-mediated detoxification and antioxidant effect, altering carcinogen metabolism, suppressing proliferation, decreasing inflammation, and enhancing antitumor immunity. In addition, several active components with diverse chemopreventive properties have been also mentioned in this review article.

Therapeutic potential of traditional chinese medicine on inflammatory diseases

Increased oxidative stress induces inflammation to several tissues/organs leading to cell death and long-term injury. Traditional Chinese Medicine (TCM) with antioxidant, anti-inflammatory, anti-apoptotic, and autophagic regulatory functions has been widely used as preventive or therapeutic strategy in modern medicine. Oxidative stress and inflammation have been widely reported to contribute to cigarette smoke-induced lung inflammation, hepatotoxicity, or sympathetic activation-induced liver inflammation, lipopolysaccharide-induced renal inflammation, and substance P-mediated neurogenic hyperactive bladder based on clinical findings. In this review, we introduce several evidences for TCM treatment including Monascus adlay (MA) produced by inoculating adlay (Cois lachrymal-jobi L. var. ma-yuen Stapf) with Monascus purpureus on lung injury, Amla (Emblica officinalis Gaertn. of Euphorbiaceae family) on hepatotoxin-induced liver inflammation, Virgate Wormwood Decoction (Yīn Chén Hāo tāng) and its active component genipin on sympathetic activation–induced liver inflammation, and green tea extract and its active components, catechins, or a modified TCM formula Five Stranguries Powder (Wǔ Lén Sǎn) plus Crataegi Fructus (Shān Zhā) on hyperactive bladder. The pathophysiologic and molecular mechanisms of TCM on ameliorating inflammatory diseases are discussed in the review.

Induction of Nrf2-dependent Antioxidation and Protection Against Carbon Tetrachloride-induced Liver Damage by Andrographis Herba (chuān xīn lián) Ethanolic Extract

Andrographis paniculata is a traditional Chinese herb and displays diverse biological activities including antioxidation, anti-tumorigenesis, anti-virus, and anti-atherogenesis. In this study, we investigated the up-regulation of ethanolic extract of A. paniculata (APE) on the antioxidant defense in rat livers and whether this enhancement protected against carbon tetrachloride (CCl₄)-induced liver damage. Male Sprague-Dawley rats were orally administered (i.g.) 0, 0.75, or 2 g/kg/d APE for 5 d. At d 6, rats were sacrificed and liver tissues were removed. Some animals (n=8) were intraperitoneally injected CCl₄ (1 mL/kg, 50% in olive oil) and blood was drawn 24 h after CCl₄ treatment. The results showed that APE increased hepatic glutathione (GSH) content and superoxide dismutase, GSH peroxidase, and GSH S-transferase activities in a dose-dependent manner (p < 0.05). Results of immunoblotting and RT-PCR revealed that rats treated with APE had higher glutamate cysteine ligase catalytic and modifier subunits, heme oxygenase 1, superoxide dismutase 1, and GSH S-transferase Ya and Yb protein and mRNA expression than those of control rats. Moreover, APE increased Nrf2 nuclear translocation and Nrf2 binding to DNA in rat liver. In the presence of CCl₄, APE decreased hepatic thiobarbituric acid-reactive substances production and plasma aspartate aminotransferase and alanine aminotransferase activities. These results suggest that APE protection against CCl₄ insult is attributed, at least in part, to its up-regulation of antioxidant defense in rat liver.

Andrographis paniculata Extract and Andrographolide Modulate the Hepatic Drug Metabolism System and Plasma Tolbutamide Concentrations in Rats

Andrographolide is the most abundant terpenoid of A. paniculata which is used in the treatment of diabetes. In this study, we investigated the effects of A. paniculata extract (APE) and andrographolide on the expression of drug-metabolizing enzymes in rat liver and determined whether modulation of these enzymes changed the pharmacokinetics of tolbutamide. Rats were intragastrically dosed with 2 g/kg/day APE or 50 mg/kg/day andrographolide for 5 days before a dose of 20 mg/kg tolbutamide was given. APE and andrographolide reduced the AUC_0–12 h of tolbutamide by 37% and 18%, respectively, compared with that in controls. The protein and mRNA levels and enzyme activities of CYP2C6/11, CYP1A1/2, and CYP3A1/2 were increased by APE and andrographolide. To evaluate whether APE or andrographolide affected the hypoglycemic action of tolbutamide, high-fat diet-induced obese mice were used and treated in the same manner as the rats. APE and andrographolide increased CYP2C6/11 expression and decreased plasma tolbutamide levels. In a glucose tolerance test, however, the hypoglycemic effect of tolbutamide was not changed by APE or andrographolide. These results suggest that APE and andrographolide accelerate the metabolism rate of tolbutamide through increased expression and activity of drug-metabolizing enzymes. APE and andrographolide, however, do not impair the hypoglycemic effect of tolbutamide.

Indigofera suffruticosa Mill extracts up-regulate the expression of the π class of glutathione S-transferase and NAD(P)H: quinone oxidoreductase 1 in rat Clone 9 liver cells

Because induction of phase II detoxification enzyme is important for chemoprevention, we study the effects of Indigofera suffruticosa Mill, a medicinal herb, on the expression of π class of glutathione S-transferase (GSTP) and NAD(P)H: quinone oxidoreductase 1 (NQO1) in rat Clone 9 liver cells. Both water and ethanolic extracts of I. suffruticosa significantly increased the expression and enzyme activities of GSTP and NQO1. I. suffruticosa extracts up-regulated GSTP promoter activity and the binding affinity of nuclear factor erythroid 2-related factor 2 (Nrf2) with the GSTP enhancer I oligonucleotide. Moreover, I. suffruticosa extracts increased nuclear Nrf2 accumulation as well as ARE transcriptional activity. The level of phospho-ERK was augmented by I. suffruticosa extracts, and the ERK inhibitor PD98059 abolished the I. suffruticosa extract-induced ERK activation and GSTP and NQO-1 expression. Moreover, I. suffruticosa extracts, especially the ethanolic extract increased the glutathione level in mouse liver and red blood cells as well as Clone 9 liver cells. The efficacy of I. suffruticosa extracts in induction of phase II detoxification enzymes and glutathione content implies that I. suffruticosa could be considered as a potential chemopreventive agent.

Suppressive effects of Indigofera suffruticosa Mill extracts on lipopolysaccharide-induced inflammatory responses in murine RAW 264.7 macrophages

Indigofera suffruticosa Mill is used as an herbal medicine for the treatment of inflammation. The aim of this study is to assess the anti-inflammatory potency of I. suffruticosa and its likely molecular mechanisms of action in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Both water and ethanolic extracts of I. suffruticosa significantly decreased LPS-induced nitric oxide (NO) as well as the expression of inducible nitric oxide synthase (iNOS), tumor necrosis factor-α, and pro-interleukin-1β. Moreover, LPS-induced inhibitory factor-κB-α phosphorylation, nuclear factor-κB (NF-κB) nuclear protein-DNA binding affinity, and NF-κB reporter gene activity were dramatically inhibited by I. suffruticosa extracts. Exogenous addition of I. suffruticosa significantly induced heme oxygenase-1 (HO-1) expression, and the presence of HO-1 small interfering RNA partly reversed the inhibitory effects of I. suffruticosa on LPS-induced NO production and iNOS expression. Furthermore, I. suffruticosa induced HO-1 expression may be through activation of the ERK/nuclear factor E2-related factor 2 pathway. Eight phenolic compounds were found in the I. suffruticosa extracts, but salicylic acid was the only one detected in the plasma of mice fed with I. suffruticosa extracts. In summary, I. suffruticosa have a strong anti-inflammatory property that diminishes pro-inflammatory mediator expressions by lessening LPS-induced NF-κB activation and inducing HO-1 expression in macrophages.

Dietary Monascus adlay supplements facilitate suppression of cigarette smoke-induced pulmonary endoplasmic reticulum stress, autophagy, apoptosis and emphysema-related PLGF in the rat

Cigarette smoke (CS) exposure may cause oxidative stress in the lung, leading to cell death and long-term injury. Monascus adlay (MA) with antioxidant components produced by inoculating adlay (Cois lachrymal-jobi L. var. ma-yuen Stapf) with Monascus purpureus may protect lung against CS-induced lung injuries in rats. MA and lovastatin had higher antioxidant activities than either M. purpureus or adlay. CS exposure caused significant lung damage, as evidenced by higher levels of reactive oxygen species (ROS), neutrophil infiltration, dityrosine and 4-HNE, as well as lower levels of Mn-superoxide dismutase and catalase expression. Lung tissues with CS exposure had higher levels of ER stress, apoptosis, autophagy and emphysema-related placenta growth factor (PlGF) expressions. All CS-induced injuries were significantly suppressed by MA supplements. MA would be a beneficial nutritional therapy to ameliorate CS-induced lung injury via preserving antioxidant defense mechanisms, decreasing oxidative stress and inhibiting ER stress, autophagy, apoptosis and emphysema-related risk factor.

Effects of Bu-Zhong-Yi-Qi-Tang on hepatic drug-metabolizing enzymes and plasma tolbutamide concentration in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Bu-Zhong-Yi-Qi-Tang (BT) is the dry powder derived from the aqueous extract of a mixture of 10 medicinal herbs. It is a traditional Chinese medicine being used for the treatment of various immune-related diseases.

AIM OF THE STUDY

To investigate the effect of BT on hepatic drug-metabolizing enzymes and its effect on plasma concentrations of tolbutamide, a substrate of CYP2C, in rats.

MATERIALS AND METHODS

EXP 1: Thirty-two male Wistar rats were divided into four groups. Rats were fed a control diet and a control diet containing 1, 2.5 and 5% (w/w) of BT, respectively, for eight weeks. The activities of the major CYP and Phase II conjugating enzymes in rat liver microsomes as well as the antioxidant system in rat liver were assessed. Exp 2: Male Wistar rats were fed a control diet or a control diet containing 2.5% of BT, respectively, for eight weeks. A single 20-mg/kg oral dose of tolbutamide was then administered to each rat. Plasma samples were collected from each rat at 0.5, 1, 2, 4 and 8h after dosing. The concentrations of tolbutamide and glucose level in plasma were determined by high-performance liquid chromatography-mass spectrometer (HPLC/MS) and enzymatic method, respectively.

RESULTS

Significant decrease in microsomal CYP2C-catalyzed diclofenac 4-hydroxylation in the liver of rats fed the BT diet was observed. Increased UDP-glucuronosyltransferase (UGT) and glutathione S-transferase (GST) activities were also observed in the liver of rats fed the diet containing 2.5 and 5% of BT. Immunoblot analyses also showed decreases of CYP2C11 proteins in the liver of BT fed rats. In addition, rats fed the 2.5% BT diet for eight weeks had no effects on the disposition of tolbutamide and reduction of glucose level in plasma after orally administered of tolbutamide.

CONCLUSIONS

Rats fed the BT diet for eight weeks may decrease CYP2C enzyme activity and protein expression and increase Phase II conjugating enzyme activities in liver. However, BT may not affect the disposition and efficacy of tolbutamide.

Effects of chitosan oligosaccharides on drug-metabolizing enzymes in rat liver and kidneys

To investigate the effect of chitosan oligosaccharides (COS) on drug-metabolizing enzymes in rat liver and kidneys, male Spraque-Dawley rats were fed a diet containing 1% or 3% COS for 5 weeks. The activities of cytochrome P450 (CYP) enzymes, UDP-glucurosyltransferase (UGT) and glutathione S-transferase (GST) in the liver and kidneys were determined. Significant decreases in microsomal CYP3A-catalyzed testosterone 6β-hydroxylation, CYP2C-catalyzed diclofenac 4-hydroxylation, and CYP4A-catalyzed lauric acid 12-hydroxylation in the liver of rats fed the COS diets were observed compared with those rats fed the control diet. Immunoblot analyses of CYP proteins showed the same trend as with enzyme activities. Increased glutathione content in liver was found in rats fed the 1% COS diet. Increased hepatic NADPH: quinone oxidoreductase 1 (NQO1) activity was found in rats fed the COS diets. In kidneys, COS had little or no effect on CYP enzyme activities. However, increased GST activity was observed in rats fed the COS diets. Moreover, a higher UGT activity was found in rats fed the 1% COS diet. Our results indicate that COS may suppress hepatic CYP enzymes and induce phase II detoxifying reactions in the liver and kidneys of rats.