Development of multi-drug resistance to anticancer drugs in HepG2 cells due to MRP2 upregulation on exposure to menthol.

BACKGROUND: Menthol exerts relaxing, antibacterial, and anti-inflammatory activities, and is marketed as a functional food and therapeutic drug. AIM: In the present study, the effects of menthol on the expression of multidrug resistance associated protein 2 (MRP2) and its association with the cytotoxicity of epirubicin (EPI) and cisplatin (CIS) were examined using HepG2 cells. METHODS: The expression levels of target genes were examined by real-time PCR. The intracellular concentration of incorporated EPI was measured by high-performance liquid chromatography. Cell viability was evaluated by MTT analysis. RESULTS: The expression of MRP2 mRNA was increased by exposing HepG2 cells to menthol for 24 hr. Consistent with a previous report suggesting an inverse correlation between MRP2 and Akt behavior, increased expression of MRP2 was also observed on suppression of the Akt function. Intracellular accumulation of EPI was significantly decreased by exposure of HepG2 cells to menthol, and a significant decrease in the intracellular concentration of EPI remaining was observed in HepG2 cells exposed to menthol. The decreased intracellular accumulation of EPI was significantly suppressed by treatment with MK-571, but not verapamil. Both EPI and CIS exerted cytocidal effects on HepG2 cells, but the decrease in cell viability was significantly attenuated by 24-hr menthol pre-exposure. CONCLUSION: These results demonstrate that menthol causes hepatocellular carcinoma to acquire resistance to anticancer drugs such as EPI and CIS by MRP2 induction.

Danazol increases the oral bioavailability of midazolam by inactivation of hepatic and intestinal CYP3A in rats.

Danazol (DNZ) is a synthetic androgen derivative used for the treatment of intractable hematological disorders. In this study, we investigated the effects of DNZ on CYP3A activity in hepatic and small intestinal microsomes and the pharmacokinetics of midazolam (MDZ), a typical substrate for CYP3A, in rats.MDZ 4-hydroxylation activities in hepatic and small intestinal microsomes significantly decreased 24 h after DNZ (100 mg/kg, i.p.) treatment. Time-dependent inactivation of MDZ 4-hydroxylation activities was noted when microsomes were pre-incubated with DNZ in the presence of a NADPH-generating system.The Western blot analysis indicated that the decrease observed in enzyme activity was not due to changes in the protein expression of CYP3A.In contrast to the intravenous administration, serum MDZ concentrations in DNZ-treated rats were markedly higher than those in control rats when administered orally. DNZ treatment increased MDZ oral bioavailability by approximately 2.5-folds.We herein demonstrated that DNZ increased the bioavailability of orally administered MDZ through irreversible inactivation of hepatic and intestinal CYP3A in rats.

Altered Gene Expression of Cytochrome P450 and ABC Transporter in Human Hepatocellular Carcinoma HepG2 Cells Exposed to Bardoxolone Methyl.

Bardoxolone methyl (BX) is expected to be an innovate therapeutic agent for chronic kidney disease (CKD). The aim of the present study was to examine whether the expression of subtypes of cytochrome P450 (CYP) and ABC transporters was altered in human hepatocellular carcinoma HepG2 cells by exposure to BX. The expression of mRNAs for CYP1A2, CYP2E1, P-glycoprotein, multidrug resistance-associated protein 1-3, and breast cancer resistance protein was significantly increased by exposure of HepG2 cells to BX, while the expression of CYP3A4 mRNA was significantly decreased under the same conditions. BX had no significant effect on the expression of mRNAs for CYP2C9 and CYP2C19 in HepG2 cells. In conclusion, this study demonstrated that the gene expression of several CYPs and ABC transporters in HepG2 cells was altered when exposed to BX, suggesting the need to pay careful attention to drug-drug interactions in patients receiving BX for CKD treatment.

Impact of Different Attitudes toward Face-to-Face and Online Classes on Learning Outcomes in Japan.

During the coronavirus disease 2019 (COVID-19) pandemic, online-based learning has become mainstream in many countries, and its learning outcomes have been evaluated. However, various studies have shown that online-based learning needs to be optimized in the future, and the number of reports for this purpose is currently not sufficient. The purpose in this study was to determine the relationship between academic performance and attitudes toward face-to-face and remote formats among Japanese pharmacy students enrolled in a course designed for knowledge acquisition. A combination of face-to-face and remote formats was used in a practice course for sixth-year pharmacy students, designed to improve academic performance through knowledge acquisition. To evaluate learning outcomes, we used a questionnaire that was administered to the course participants and the results of examinations conducted before and after the course. Online-oriented and face-to-face-oriented groups differed in their attitudes toward the ease of asking questions of faculty and communicating with the faculty members and classmates in each format. In a knowledge acquisition course for Japanese pharmacy students, the study revealed that the same academic outcomes were achieved, regardless of the students' own perceptions of their aptitude for face-to-face or remote learning style.

Doxorubicin alters the disposition of phenytoin by reducing its metabolic elimination and binding affinity to serum albumin in rats.

OBJECTIVES: We investigated the pharmacokinetic interaction of doxorubicin (DOX) with phenytoin (PHT) and the underlying mechanism in rats to clarify why the serum PHT concentration decreases despite the impaired PHT metabolic capacity in patients receiving DOX. METHODS: Rats were administered 15 mg/kg of DOX or saline alone. The pharmacokinetic disposition of intravenously administered PHT was examined 4 days after DOX exposure. Enzyme kinetics of CYP2C-dependent PHT p-hydroxylation were analysed using hepatic microsomes. The unbound PHT concentration in serum was measured by the ultrafiltration method, and the relationship between the unbound fraction (fu) and serum albumin level was assessed. KEY FINDINGS: The total clearance (CLtot) of PHT was significantly increased by DOX, but the activity of PHT p-hydroxylation conversely decreased. The unbound serum PHT concentration and its fu were significantly higher in the DOX group than in the control group, and the CLtot/fu, a measure of intrinsic clearance, significantly decreased. An increase in the fu was observed even when using a serum sample with an albumin concentration equal to that in the control group. CONCLUSIONS: DOX treatment increases the unbound serum PHT concentration by depressing the metabolic capacity and alters the total PHT by reducing serum albumin and its affinity to PHT.

Differences in Transport Characteristics and Cytotoxicity of Epirubicin and Doxorubicin in HepG2 and A549 Cells.

BACKGROUND/AIM: Epirubicin (EPI), an epimer of doxorubicin (DOX), and DOX are anthracycline agents with broad-spectrum antitumor activity. The aim of the present study was to elucidate the transport characteristics of EPI and DOX in human hepatocellular carcinoma HepG2 cells and human non-small cell lung cancer A549 cells, and to examine the relationship of intracellular drug accumulation with their cytotoxic effects. MATERIALS AND METHODS: Intracellular concentrations of EPI and DOX were measured using high-performance liquid chromatography (HPLC). Expression level of targeted genes was analyzed by real-time quantitative PCR. Cell viability was evaluated using the MTT assay. RESULTS: Similar to DOX, EPI was taken up into HepG2 and A549 cells by organic cation transporter 6 and passive diffusion; however, the efficiency of saturable and non-saturable uptake of EPI was greater than that of DOX in both cell types. EPI served as a substrate of P-glycoprotein and multidrug associated protein (MRP) 1 and MRP2 similarly to DOX, but the efflux efficiency of each transporter was markedly different between EPI and DOX. The intracellular accumulation of EPI was significantly greater than that of DOX in all cells, and the accumulated level reflected the cytotoxic effects of these drugs. However, the intracellular drug amount did not correspond to the degree of cytotoxicity when compared between HepG2 and A549 cells, which can be explained by the higher expression of Bcl-xl in A549 cells. CONCLUSION: This study suggested that the transport characteristics are markedly different between EPI and DOX in HepG2 and A549 cells, and that intracellular accumulation is the predominant factor affecting the cytotoxicity of EPI and DOX in individual cells.

Effects of concurrent and staggered dosing of semi-solid enteral nutrients on pharmacokinetic behavior of antiepileptic drugs after oral administration in rats.

BACKGROUND: The use of enteral nutrients plays a highly important role in accurate nutrition management, but limited information is currently available on the cautionary points of semi-solid enteral nutrients. AIM: In this study, we examined whether the pharmacokinetic profiles of sodium valproate (SVA), levetiracetam (LEV), and carbamazepine (CBZ) are affected by altering the dosing time of RACOL®-NF Semi Solid for Enteral Use (RASS), a prescribed semi-solid formula. We also investigated whether the pharmacokinetic interaction observed in this study can be avoided by staggered dosing of the chemical drug and semi-solid enteral nutrient. METHODS: The plasma concentration of SVA, LEV and CBZ after oral administration was measured by LC-MS/MS method. RESULTS: There was no difference in pharmacokinetic characteristics of SVA and LEV when the dosing time of RASS was altered. On the other hand, the plasma concentration of CBZ after oral administration at all sampling points decreased with the extension of the dosing time of RASS, which was consistent with the Cmax and AUC. However, no significant difference was observed in the pharmacokinetic profiles or parameters of CBZ between the short-term and long-term RASS dosing groups by prolonging the administered interval of CBZ and RASS for 2 hr. CONCLUSION: We concluded that the pharmacokinetic profiles of CBZ, but not SVA and LEV, after its oral administration are affected by the dosing time of RASS, but staggered administration of CBZ and RASS prevented their interaction.

Effects of semi-solidification of enteral nutrients on the pharmacokinetic behavior of orally administered carbamazepine in rats.

The use of semi-solid enteral nutrients plays an extremely important role in accurate nutrition management. In the present study, we compared the pharmacokinetic profile of orally administered carbamazepine (CBZ) in rats treated with liquid RACOL®, semi-solid RACOL®, and HINE E-gel®, which are enteral nutrients marketed in Japan. Since liquid and semi-solid formulations are both marketed in Japan for RACOL®, liquid RACOL® was orally administered to control rats. The serum concentration of CBZ at each sampling point was lower in the semi-solid RACOL®-treated group than in the liquid RACOL®-treated group. No significant differences were observed in the pharmacokinetic behavior of CBZ between the semi-solid RACOL®-treated and HINE E-gel®-treated groups. Regarding pharmacokinetic parameters, the impact of the area under the curve (AUC0→5h) was the liquid RACOL® group > the semi-solid RACOL® group ≈ the HINE E-gel® group. Therefore, we concluded that serum concentrations of CBZ were lower when concurrently treating with semi-solid enteral nutrients than when simultaneously processing liquid enteral nutrients.

Pharmacokinetic interference of doxorubicin with tolbutamide due to reduced metabolic clearance with increased serum unbound fraction in rats.

The study examined the effect of doxorubicin (DOX) on the hepatic expression of CYP2C and its activity for metabolizing tolbutamide (TB), a specific CYP2C substrate, in rats and whether the pharmacokinetics of tolbutamide were altered by doxorubicin exposure. The expression level of hepatic CYP2C11 was depressed 1 day after doxorubicin administration (day 1), and this effect on CYP2C11 was augmented on day 4. However, the expression level of hepatic CYP2C6 remained unchanged. The activity of tolbutamide 4-hydroxylation in hepatic microsomes was decreased with time following doxorubicin administration. Regarding the enzyme kinetic parameters for tolbutamide 4-hydroxylation on day 4, the maximum velocity (Vmax ) was significantly lower in the DOX group than that in the control group, while the Michaelis constant (Km ) was unaffected. On pharmacokinetic examination, the total clearance (CLtot ) of tolbutamide on day 4 was increased, despite the decreased metabolic capacity. On the other hand, the serum unbound fraction (fu ) of tolbutamide was elevated with a reduced serum albumin concentration in the DOX group. Contrary to CLtot , CLtot /fu , a parameter approximated to the hepatic intrinsic clearance of unbound tolbutamide, was estimated to be significantly reduced in the DOX group. These findings indicate that the metabolic capacity of CYP2C11 in the liver is depressed time-dependently by down-regulation after doxorubicin exposure in rats, and that the decreased enzyme activity of TB 4-hydroxylation in hepatic microsomes reflects the pharmacokinetic change of unbound tolbutamide, not total tolbutamide, in serum.

Enhanced anti-cancer activity by menthol in HepG2 cells exposed to paclitaxel and vincristine: possible involvement of CYP3A4 downregulation.

Background Menthol is widely used as a constituent of functional foods and chemical drugs. In the present study, we investigated changes in the expression of cytochrome P450 isoform CYP3A4mRNA after treating human hepatocellular carcinoma HepG2 cells with menthol. We also examined the effects of pretreatment with menthol on the cytotoxic activity of paclitaxel (PAC) and vincristine (VIN), which are substrates of CYP3A4, in the cells. Methods HepG2 cells were maintained in Dulbecco's Modified Eagle's Medium. Expression of CYP3A4 was examined by the real-time polymerase chain reaction. Survival rate of HepG2 cells was evaluated by the MTT assay. Results The gene expression level of CYP3A4 in HepG2 cells was significantly reduced by treatment with menthol for 1 day. The viability of HepG2 cells was not affected by treatment with menthol alone once a day for two consecutive days. The degree of reduction in cell viability by PAC or VIN in HepG2 cells was significantly increased by menthol treatment for 24 h prior to exposure to these anti-cancer drugs. Conclusions These results demonstrate that menthol enhanced the anti-tumor effects of PAC and VIN through the downregulation of CYP3A4 in HepG2 cells without exerting cytotoxic activity.

Conflicting alterations in hepatic expression of CYP3A and enzyme kinetics in rats exposed to 5-fluorouracil: relevance to pharmacokinetics of midazolam.

1. 5-Fluorouracil (5-FU) is a pyrimidine derivative widely used for the treatment of cancer. In this study, we investigated the effects of 5-FU on the protein expression of hepatic CYP3A and their enzyme activity for metabolizing midazolam (MDZ), a typical substrate of CYP3A, in rat liver microsomes. We also examined the pharmacokinetic behavior of intravenously administered MDZ in rats treated with 5-FU (120 mg/kg, ip). 2. 5-FU was shown to induce hepatic CYP3A2 protein 2 days after administration without changing the expression of CYP3A1/3A23. However, affinity of 5-FU-inducible CYP3A protein to MDZ for its 4- and 1'-hydroxylation was decreased. Furthermore, the susceptibility of MDZ hydroxylation activity to a CYP3A inhibitor differed between the control and 5-FU groups. 3. Pharmacokinetic analysis of the MDZ disposition demonstrated no significant differences in the total clearance (CLtot) and elimination rate constant (ke) between the control and 5-FU-treated rats. Lack of alteration in the metabolic clearance of MDZ may be attributable to the induction of CYP3A protein with reduced affinity for the substrate of CYP3A enzymes. 4. Our findings provide novel information regarding the manifestation of inductive and interfering actions of 5-FU toward hepatic CYP3A to help in assessing the pharmacokinetics of CYP3A substrate drugs.

Alterations in Pharmacokinetics of Orally Administered Carbamazepine in Rats Treated with Sodium alginate: Possible Interaction between Therapeutic Drugs and Semi-solid Enteral Nutrients.

OBJECTIVE: The use of enteral nutrients plays an extremely important role in accurate nutrition management. Sodium alginate (SA) is frequently used for the semi-solidification of enteral nutrients. In the present study, we investigated whether the pharmacokinetic profile of orally administered carbamazepine (CBZ) is altered by a treatment with SA immediately before and after dosing of the drug. Furthermore, the adsorption effects of SA on CBZ were examined using an in vitro analysis. METHOD: SA was orally administered to rats just before and immediately after CBZ dosing. The CBZ concentration profile following its oral administration was analyzed by a non-compartmental method. The adsorption of CBZ onto SA was evaluated after centrifugation using an ultrafiltration device. FINDINGS: The serum concentration of orally administered CBZ at each sampling point was reduced by the treatment with SA, and the extent of the decrease observed in the concentration of CBZ was larger when SA was ingested immediately after administration of the drug, which was consistent with the alteration observed in the value of the area under the curve (AUC). No significant differences were noted in the elimination rate at the terminal phase (ke) among the groups. In the in vitro assay, CBZ was adsorbed by SA in the solution used to reflect fluid in the intestinal tract. CONCLUSIONS: The pharmacological efficacies of CBZ might be reduced by SA through the pharmacokinetic interactions, and that the careful attention should be paid to the timing of administration of CBZ and semi-solid enteral nutrients.

Compatibility of Intravenous Fat Emulsion with Antibiotics for Secondary Piggyback Infusion.

BACKGROUND: The Guidelines for Parenteral and Enteral Nutrition in Japan state that parenteral fat emulsion can be infused through a secondary administration set. We tested the compatibility of fat emulsion with antibiotics in piggyback infusions in terms of changes in the size distribution of fat particles. METHODS: Test mixtures of 5% glucose solution, fat emulsion, and 25 antibiotic agents were prepared in the ratio appropriate for piggyback infusion (33: 10: 40) and analyzed serially for the number of fine particles by size using a light-shielded automatic fine particle counter. RESULTS: No marked changes were observed in the 12 ß-lactam antibacterial drugs, clindamycin phosphate, teicoplanin, trimethoprim/sulfamethoxazole, and micafungin sodium even at 24 h after preparation. The particle size in the mixture containing vancomycin hydrochloride, levofloxacin hydrate, metronidazole, and fluconazole gradually increased after preparation. The particle size in the mixture containing gentamicin sulfate, arbekacin sulfate, minocycline hydrochloride, ciprofloxacin, and fosfomycin sodium changed significantly after preparation. CONCLUSIONS: The changes in the particle size observed with some drugs suggest that they may cause changes in the lipid particle size during administration and, therefore, those antibiotics agents should not be administered concurrently with fat emulsion.

Pharmacokinetics and metabolic elimination of tolbutamide in female rats: Comparison with male rats.

As there are to be known gender differences in the expression profiles of rat hepatic CYP2C, we examined the pharmacokinetic behavior of tolbutamide (TB), a typical probe for CYP2C, and hepatic enzyme activities for metabolizing TB in female rats to compare with male rats. On the pharmacokinetic analysis of TB after intravenous administration to female rats, the elimination rate constant at the terminal phase (ke ), total clearance (CLtot ) and the apparent volume of distribution at steady-state (Vdss ) were significantly lower than in male rats. The binding rates of TB to serum protein were similar in male and female rats, indicating that the change in unbound TB concentration in serum is not associated with the difference in the pharmacokinetic disposition of TB. On metabolic examination using hepatic microsomes, the maximum reaction velocity (Vmax ) of the metabolic conversion from TB to 4-hydroxytolbutamide (4-OH-TB) in female rats was lower than that in male rats, although there was no significant difference in the Michaelis constant (Km ) between genders. Consistent with this, the Vmax -to-Km ratio (Vmax /Km ) was significantly lower in female rats than in male rats. Therefore, the low in vitro CYP2C-dependent activity for hepatic TB removal in female rats provided a clear explanation for the lower in vivo elimination clearance of TB. Our findings strongly suggest that there is a gender difference in the metabolic capacity to eliminate drugs that serve as substrates of hepatic CYP2C enzymes in rats.

Prevention of Doxorubicin-Induced Renal Toxicity by Theanine in Rats.

Doxorubicin (DOX) is a highly potent anti-neoplastic agent widely used in clinical practice, but its dosage and duration of administration are strictly limited due to dose-related organ damage. In the present study, we examined whether theanine, an amino acid derivative found in green tea leaves, can protect against DOX-induced acute nephrotoxicity in rats. Decreases in the creatinine clearance by DOX administration were attenuated by concurrent treatment with theanine, which was consistent with the change in histological renal images assessed by microscopic examination. Theanine had no effect on the distribution of DOX to the kidney. The production of lipid peroxide in the kidney after DOX administration was suppressed by concurrent treatment with theanine. Reduced glutathione content, but not superoxide dismutase activity, was decreased following DOX administration, whereas this change was suppressed when theanine was given in combination with DOX. These results suggest that theanine prevents DOX-induced acute nephrotoxicity through its antioxidant properties.

Bactericidal effects of deep ultraviolet light-emitting diode for solutions during intravenous infusion.

Background: Ultraviolet irradiation is effectively used as a disinfection method for inactivating microorganisms. Methods: We investigated the bactericidal effects by irradiation with a deep-ultraviolet light-emitting diode (DUV-LED) on the causative microorganisms of catheter related blood stream infection contaminating the solution for intravenous infusion. For irradiation, prototype modules for water disinfection with a DUV-LED were used. Experiments were conducted on five kinds of microorganisms. We examined the dependence of bactericidal action on eleven solutions. Administration sets were carried out three types. Results: When the administration set JY-PB343L containing the infusion tube made of polybutadiene was used, the bactericidal action of the DUV-LED against all tested microorganisms in the physiological saline solutions was considered to be effective. We confirmed that the number of viable bacteria decreased in 5% glucose solution and electrolyte infusions with DUV-LED irradiation. Conclusions: These results indicate that the DUV-LED irradiation has bactericidal effects in glucose infusion and electrolyte infusions by irradiating via a plasticizer-free polybutadiene administration set. We consider DUV-LED irradiation to be clinically applicable.

In vitro and in vivo effects of selected fibers on the pharmacokinetics of orally administered carbamazepine: Possible interaction between therapeutic drugs and semisolid enteral nutrients.

OBJECTIVE: The management of nutrition using semisolid enteral nutrients is considered useful for avoiding the adverse effects associated with liquid enteral nutrients. In the present study, we used an in vitro analysis to investigate whether carbamazepine (CBZ) is adsorbed by the fibers included in semisolid enteral nutrients. The effects of these fibers on the pharmacokinetic profile of CBZ following its oral administration were also examined in rats. METHODS: The adsorption of CBZ onto fibers was examined by absorbance monitoring of the filtrate after centrifugation using an ultrafiltration device. Viscosities of each solution were measured by rotational viscosimeter. The CBZ concentration profile after its oral administration (50 mg/kg) was analyzed by a noncompartmental method. RESULTS: In the two solutions used to reflect gastric juice and fluid in the intestinal tract, CBZ was more strongly adsorbed by water-soluble fibers (guar gum and xanthan gum) than by insoluble fibers (dextrin hydrate). The adsorption of CBZ also was observed even if the concentrations of guar gum and xanthan gum were reduced to such an extent that viscosity was 0 Paï½¥s. The pharmacokinetic examination of orally administered CBZ revealed that the area under the curve was significantly lower in the guar gum and xanthan gum groups than in the control group. CONCLUSION: CBZ was adsorbed by fibers used for the semisolidification of enteral nutrients, which may be partially responsible for the alterations observed in the pharmacokinetic profile of CBZ.

Altered tolbutamide pharmacokinetics by a decrease in hepatic expression of CYP2C6/11 in rats pretreated with 5-fluorouracil.

1. We investigated the change in the pharmacokinetic profile of tolbutamide (TB), a substrate for CYP2C6/11, 4 days after single administration of 5-fluorouracil (5-FU), and the hepatic gene expression and activity of CYP2C6/11 were also examined in 5-FU-pretreated rats. 2. Regarding the pharmacokinetic parameters of the 5-FU group, the area under the curve (AUC) was significantly increased, and correspondingly, the elimination rate constant at the terminal phase (ke) was significantly decreased without significant change in the volume of distribution at the steady state (Vdss). 3. The metabolic production of 4-hydroxylated TB in hepatic microsomes was significantly reduced by the administration of 5-FU. 4. The expression level of mRNAs for hepatic CYP2C6 and CYP2C11 was significantly lower than in the control group when the rats were pretreated with 5-FU. 5. These results demonstrated that the pharmacokinetic profile of TB was altered by the treatment with 5-FU through a metabolic process, which may be responsible for the decreased CYP2C6/11 expression at mRNA levels.

Water Soluble Vitamins Enhance the Growth of Microorganisms in Peripheral Parenteral Nutrition Solutions.

Peripheral parenteral nutrition (PPN) solutions contain amino acids, glucose, and electrolytes, with or without some water soluble vitamins. Peripheral venous catheters are one of the causes of catheter related blood stream infection (CRBSI), which requires infection control. In Japan, PPN solutions have rarely been prepared under aseptic conditions. However, in recent years, the necessity of adding vitamins to infusions has been reported. Therefore, we investigated the effects of water soluble vitamins on growth of microorganisms in PPN solutions. AMINOFLUID® (AF), BFLUID® (BF), PARESAFE® (PS) and PAREPLUS® (PP) PPN solutions were used. Water soluble vitamins contained in PP were also used. Causative microorganisms of CRBSI were used. Staphylococcus epidermidis decreased after 24 hours or 48 hours in all solutions. On the other hand, Escherichia coli, Serratia marcescens, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans increased, especially in PP. When each water soluble vitamin was added to BF and PS, growth of S. aureus was greater in solutions that contained nicotinamide than in solutions that contained other vitamins. As for C. albicans, they grew in all test solutions. C. albicans grew especially well in solutions that contained biotin. When commercial amino acids and glucose solutions with electrolytes are administered, in particular those containing multivitamins or water soluble vitamins, efforts to control infection must be taken to prevent proliferation of microorganisms.

Protective effects of taurine on doxorubicin-induced acute hepatotoxicity through suppression of oxidative stress and apoptotic responses.

The organ toxicity of doxorubicin (DOX), an anthracycline antineoplastic agent, narrows the therapeutic window despite its clinical usefulness. In the present study, we determined whether taurine protected against DOX-induced hepatic injury, and explored the molecular mechanisms underlying the suppressive effects of taurine in terms of alterations in oxidative stress and apoptotic responses. DOX-induced body weight loss was completely suppressed by taurine treatment. Elevations in the serum activity levels of lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase by DOX were also dose-dependently attenuated by a concurrent treatment with taurine. Superoxide dismutase activity and reduced glutathione content in the liver were decreased following the administration of DOX, whereas these changes were suppressed when 10 mg/kg taurine was given in combination with DOX. Taurine attenuated the increased expression of mRNAs for Fas and Bax after DOX exposure. Furthermore, the formation of cleaved caspase-3 protein in the group given DOX with taurine was lower than that in the group treated with DOX alone. Our results suggest that taurine can protect against DOX-induced acute hepatic damage, the underlying mechanism of which is attributable to the suppression of oxidative stress and apoptotic responses.