ABSTRACT
Wuzhi tablet (WZ) is a prescribed herbal medicine extracted from Schisandra sphenanthera, which is widely used to protect the liver injury and drug-induced hepatotoxicity in clinical practices. Previous studies showed that WZ significantly increased the blood concentrations of tacrolimus, cyclosporine A, paclitaxel by inhibiting the cytochrome P450 3A (CYP3A)-mediated metabolism. CYP3A4 and CYP3A5 are the most important isoenzymes among the CYP3A subfamily. However, there are some differences in the catalytic and inhibitory activities between CYP3A4 and CYP3A5, which may lead to different risk of drug-drug and herb-drug interactions, and the risks may be further amplified in vivo. Currently, few reports have compared the herbal medicine inhibitory effects between CYP3A4 and CYP3A5 mediated metabolic reactions. Therefore, detailing the inhibitory effect of WZ on CYP3A4 and CYP3A5 will help understand and predict the potential herb-drug interaction. The results showed that WZ inhibited CYP3A4 and CYP3A5 in a NADPH-, time- and concentration- dependent manner. WZ showed more potent inhibition on CYP3A5 than CYP3A4. Cautions warranted when combining WZ with other therapeutic drugs to avoid the potential herb-drug interaction.
ABSTRACT
Acetaminophen (APAP, also known as paracetamol)-induced liver injury is the leading cause of drug-induced liver injury in the world. Wuzhi Tablet (WZ, an ethanol extract of Schisandra sphenanthera) is widely used in clinical practice to protect liver function. Our previous studies have shown that pretreatment with WZ for 3 days can significantly protect against APAP-induced liver injury; however, the effect of different intervals between APAP and WZ treatment on APAP-induced liver injury remains unclear. In this study, the change in liver injury indexes, APAP metabolites, and the activity of cytochrome P450 (CYP450) enzymes after treatment with WZ and APAP at different intervals were determined. The animal experiment was reviewed and approved by the Animal Ethics Committee of Sun Yat-sen University. The results show that 0 h, 0.5 h, and 2 h pretreatment with WZ significantly protected against APAP-induced liver injury in mice, as evidenced by a significant decrease in biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and malonaldehyde (MDA). WZ inhibited the metabolic activation of APAP mediated by CYP450 enzymes and reduced the formation of APAP metabolites. This study further demonstrates that pretreatment with WZ at different intervals (0 h, 0.5 h, and 2 h before APAP dosing) exerts a significant hepatoprotective effect against APAP-induced liver injury, and a single-dose of WZ inhibits the activity of CYP450 enzymes related to APAP metabolic activation, thereby protecting against APAP-induced hepatotoxicity.
ABSTRACT
This study was aimed to investigate the effects of six Schisandra lignans of Wuzhi tablet (WZ, a preparation of ethanol extract of Schisandra sphenanthera) on the pharmacokinetic process of digoxin (DG, a classical P-gp substrate) after intravenous and oral administration in rats. The effect of Schisandra lignans on the transportion of DG in Caco-2 cells was further elucidated. Our data showed that the plasma concentrations of DG were increased to different extent following co-administration of schisandrin A, schisandrin B, schisandrol B and schisantherin A, respectively. Schisandrol B showed the most potent effect among the six lignans. However, schisandrin C and schisandrol A showed little effect on pharmacokinetic of DG. Schisandrol B led to 99.0% (P < 0.05) and 109.2% (P < 0.05) increase in the AUC after orally or intravenously administered of DG, suggesting that co-administration of schisandrol B induced a more potent effect on increasing hepatic bioavailability of DG than that of intestinal. Furthermore, in vitro transport experiment showed that schisandrin A, schisandrin B, schisandrol B and schisantherin A inhibited P-gp-mediated efflux of DG, suggested that these lignans inhibited the P-gp-mediated efflux of DG. In conclusion, the exposure of DG in rats was increased when co-administered with Schisandra lignans, and schisandrol B showed the strongest effect. The dramatic increase in oral bioavailability of digoxin in the presence of schisandrol B may be due to the inhibition of hepatic/renal P-gp activity.
ABSTRACT
OBJECTIVE:To establish a method for content determination of schizantherin E,gomisin J,angeloylgomisin H,schisantherin A,schisantherin B,schisanhenol,anwuligan,schizandrin A,schizandrin B and schizandrin C in Wuzhi tablets.METHODS:RP-HPLC method was adopted.The determination was performed on Symmetry C18 column with acetonitrile-0.1％ phosphoric acid solution (gradient elution) at the flow rate of 1.0 mL/min.The detection wavelength was set 225 rm,and the column temperature was 30 ℃.The sample size was 10 μL.RESULTS:The linear ranges of schizantherin E,gomisin J,angeloylgomisin H,schisantherin A,schisantherin B,schisanhenol,anwuligan,schizandrin A,schizandrin B and schizandrin C were 2.25-67.5ng(r=0.999 6),2.1-63 ng(r=0.999 8),28-840 ng(r=0.999 9),124.6-3 738 ng(r=0.999 9),22.7-681 ng(r=0.999 9),32.7-981 ng(r=0.999 9),47-1 410 ng(r=0.999 9),208-6 240 ng(r=0.999 9),5.36-160.8 rig(r=0.999 9),4.48-134.4 ng(r=0.999 8).The limits of quantitation were 14.17,13.32,9.33,11.37,14.62,19.88,14.66,12.50,16.40,13.55 rg.The limits of detection were 4.62,4.60,3.08,3.76,4.81,6.74,4.93,4.16,5.86,5.03 ng.RSDs of precision,stability and reproducibility tests were less than 3.0％;the recoveries were 96.36％-100.00％(RSD=1.83％,n=6),95.00％-100.00％(RSD=2.07％,n=6),95.00％-98.00％(RSD=1.22％,n=6),95.37％-98.91％ (RSD=1.29％,n=6),95.62 ％-103.71％ (RSD=2.85％,n=6),97.33％-102.67％ (RSD=2.00％,n=6),95.00％-99.33％ (RSD=1.75％,n=6),97.24％-104.93％ (RSD=2.63％,n=6),95.00％-97.50％ (RSD=1.42％,n=6),96.00％-102.00％ (RSD=2.45％,n=6),respectively.CONCLUSIONS:The developed method is accurate,sensitive and reproducible,and it can be used for content determination of 10 lignanoids in Wuzhi tablets.
ABSTRACT
The study aims to evaluate the effect of long-term pretreatment of the rat with Wuzhi tablet (WZ) on hepatic and intestinal CYP3A mRNA and protein expression and activity. Male Sprague-Dawley rats were orally administered of midazolam (2 mg·kg-1) with or without 14 days of pretreatment of WZ (0.25 g·kg-1) to determine CYP3A activity. Meanwhile, RNA and protein of rats liver and intestine samples were prepared 24 h after the last dose of 14 days of WZ treatment to determine CYP3A mRNA and protein expression. Long-term treatment of WZ increased the mRNA expression of hepatic Cyp3a1, Cyp3a9 and intestinal Cyp3a9 by 54.6%, 188.3% (PP<0.05), respectively;and increased the protein expression of hepatic CYP3A by 43.2%. However, after long-term treatment of WZ, the AUC of orally administered of midazolam in the WZ group was increased 29.9% (WZ pretreatment group) and 154.2% (WZ coadministered group) compared to that of control group. In conclusion, long-term treatment of WZ increased the mRNA and protein expression of CYP3A, while could inhibit the activity of CYP3A.
ABSTRACT
This study was aimed to determine the hepatic and small intestinal distribution of active lignans in rats after treated with Wuzhi tablet (WZ, Schisandra sphenanthera extract) by LC-MS/MS method. Male Sprague-Dawley rats were sacrificed at 0.25, 1.5, 4, 6, 10, 24 h after an oral administration of WZ, and then hepatic and small intestinal samples were collected for analysis. The results showed that concentrations of lignans in liver and small intestine of rats were decreased with WZ pretreated time. The concentrations of all lignans in rat liver and small intestine at 0.25 h were the highest after a single oral administration. All lignans was undetectable in all tissues 24 h after oral dosing, suggesting lignans of WZ were eliminated rapidly in rats. The concentrations of schisandrin A, schisandrol B and schisantherin A in small intestine were much higher than those in the liver, suggesting the effect of WZ on the intestinal metabolism enzyme might be more potent than that on the liver. In short, the current results suggest that lignans of WZ were not accumulated in rat liver and small intestine. The concentrations of lignans of WZ in small intestine were much higher than those in liver.