Influence of Gegenqinlian decoction on pharmacokinetics and pharmacodynamics of saxagliptin in type 2 diabetes mellitus rats.

Gegenqinlian decoction (GQD) is a classic prescription of traditional Chinese medicine (TCM), which originated from Shanghanlun. The combination of GQD and hypoglycemic drugs (saxagliptin, Sax, metformin) is often used to treat Type 2 diabetes mellitus (T2DM) in TCM clinics. However, the herb-drug interactions (HDIs) between GQD and hypoglycemic drugs are still unclear. In order to determine the safety of the combination, we assessed the influences of GQD on the pharmacokinetics and pharmacodynamics of Sax in T2DM rats. The plasma concentration of Sax (5 mg/kg) pretreated with GQD (freeze-dried powder, 1.35 g/kg) or not was determined by high-performance liquid chromatography (HPLC), and pharmacokinetics parameters were calculated. The influence of GQD on the pharmacodynamics of Sax was investigated by detecting the levels of weight, (see abbreviations list) OGTT, TC, TG, LDL-C, HDL-C, FBG, FINS, HOMA-IR, QUICKI, AST, ALT, and the liver coefficient. The Cmax , AUC0-t ,and AUC0-∞ of Sax increased significantly in the combination group whether in normal or T2DM rats. The results of pharmacodynamics showed that the weight of rats in each treatment group increased. FBG, TC, TG, LDL-C, and HOMA-IR decreased, HDL-C, FINS, and QUICKI increased significantly (p < 0.05) compared with the model control group. The result showed that the combination of GQD and Sax could not only improve the hypoglycemic effect but also increase the plasma exposure of Sax. The potential HDIs between GQD and Sax should be taken into consideration in clinics. Moreover, for the complexity of the human compared with experimental animals, as well as genetic differences, the in-depth study should be carried out to assess the uniformity of the pharmacokinetics and pharmacodynamics between rats and humans.

Influence of Gegenqinlian Decoction on Pharmacokinetics and Pharmacodynamics of Atorvastatin Calcium in Hyperlipidemic Rats.

BACKGROUND AND OBJECTIVES: Gegenqinlian decoction (GQD), a classic traditional Chinese medicine (TCM), was described in Shanghan Lun. GQD is often combined with antihyperlipidemic drugs (mainly atrovastatin calcium) in TCM clinics. However, the herb-drug interaction between GQD and atrovastatin calcium (AC) is still unknown. To determine whether the combination is safe, we evaluated the effects of GQD on the activities of cytochrome P450 (CYP) 3A2 enzyme and investigated the impact of GQD on the pharmacokinetics and pharmacodynamics of AC in rats. METHODS: The pharmacokinetics of AC (10 mg/kg) with or without pretreatment with GQD (freeze-dried powder, 1.35 g/kg) were investigated using HPLC. The influence of GQD on pharmacodynamics of AC were determined by detecting the levels of serum total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Moreover, the probe drug method was used to explore the effect of GQD on CYP3A2 activity. RESULTS: The pharmacokinetic parameters of AC combined with GQD were significantly affected (P < 0.05) in hyperlipidemic rats. The serum TC, TG and LDL-C levels of the combination were significantly reduced (P < 0.05), and the serum HDL-C level was significantly increased (P < 0.05) compared with AC/GQD alone. AST and ALT activities treated with both GQD and AC+GQD group were significantly reduced (P < 0.05) compared with AC group. There was a significant difference in the pharmacokinetic parameters of midazolam between control and GQD groups (P < 0.05). Maximum concentration (Cmax), area under the concentration-time curve (AUC) from time 0 to the last quantifiable concentration (AUC0-t) and AUC from time 0 to infinity (AUC0-∞) increased significantly in GQD group. CONCLUSIONS: The result suggested that GQD combined with AC can improve the lipid-lowering effect of AC and reduce the damage of AC to the liver simultaneously. However, GQD can inhibit the activity of CYP3A2 in hyperlipidemic rats and increase the blood concentration of AC. Therefore, the clinical dose of AC should be adjusted when they are combined. Since the study was conducted in rats,  further research should be carried out to assess the uniformity of the pharmacokinetics and pharmacodynamics between rats and humans.

[Effect and mechanism of astragaloside â £ on Toll-like receptor pathway in fibrotic mice after renal ischemia-reperfusion].

The aim of this paper is to study the effect of astragaloside Ⅳ on renal fibrosis mice with ischemia-reperfusion injury (IRI) and discuss the mechanism. Male C57BL/6 50 mice were randomly divided into four groups, namely Sham-operated group, model group, AS-Ⅳ prevention group and AS-Ⅳ treatment group. Since the day of surgery, the mice in astragaloside Ⅳ prevention group were treated with astragaloside Ⅳ by gavage for 30 days at the dose of 30 mg·kg⁻¹·d⁻¹. At the 60th day after surgery, the mice in astragaloside Ⅳ treatment group were treated with astragaloside Ⅳ 100 by gavage for 30 days at the dose of 30 mg·kg⁻¹·d⁻¹. The mice in Sham-operated group and model group were treated with double distilled water containing 0.1% ethanol instead of astragaloside Ⅳ. Serum creatinine and blood urea nitrogen were detected by chemical methods. Histopathological changes and collagen deposition of affected kidneys were observed under optical microscope by HE and Masson staining. The expression levels of Toll like receptor pathway related molecules (TLR4,MyD88,TRAF6,TRAM,TRIF,NF-κB,TNF-α,IL-6, IFN-γ) in affected kidneys were observed by immunohistochemistry, Western blot methods and reverse transcription-PCR atprotein and mRNA levels in each group. The results showed that the degrees of fibrosis and histopathological damage of affected kidneys of mice in model group were the most obvious. And the expression levels of TLR4/MyD88 dependent signaling pathway-related molecules (TLR4 and MyD88, TRAF6 and NF-κB) in affected kidneys of mice in model group were the highest. At the same time, there was no difference in the expression levels of TLR4/MyD88 independent signaling pathway-related molecules（TRAM, TRIF）among sham-operated group, model group, astragaloside IV prevention group and astragaloside Ⅳ treatment group. In astragaloside Ⅳ prevention group and astragaloside Ⅳ treatment group, the injury of affected kidney was obviously reduced, and the protein expression levels of TLR4/MyD88 dependent signaling pathway-related molecules were also correspondingly reduced; at the same time, the expressions of terminal inflammatory cytokines (TNF-α,IL-6, IFN-γ) were suppressed. Therefore, astragaloside Ⅳ may improve renal interstitial fibrosis in mice after IRI by inhibiting the expression of TLR4/MyD88 dependent signaling pathway and the release of inflammatory cytokines (TNF-α,IL-6, IFN-γ), while the TLR4/MyD88 independent signaling pathway may not be involved in the process of renal fibrosis after ischemia-reperfusion injury.