Context: Recent research has demonstrated that vitexin exhibits a prominent first-pass effect. In this light, it is necessary to investigate the causes of this distinct first-pass effect. Objective: The aim of this study was to evaluate hepatic, gastric, and intestinal first-pass effects of vitexin in rats and, furthermore, to investigate the role of P-glycoprotein (P-gp) and cytochrome P450 3A (CYP3A) in the absorption and secretion of vitexin in the duodenum. Materials and methods: Vitexin was infused into rats intravenously, intraportally, intraduodenally, and intragastrically (30 mg/kg). In addition, verapamil (50 mg/kg), a common substrate/ inhibitor of P-gp and CYP3A, was also instilled with vitexin into the duodenum to investigate the regulatory action of P-gp and CYP3A. The plasma concentrations of vitexin were measured by the HPLC method using hesperidin as an internal standard. Results: The hepatic, gastric, and intestinal first-pass effects of vitexin in rats were 5.2%, 31.3%, and 94.1%, respectively. In addition, the total area under the plasma concentration-time curve from zero to infinity (AUC) of the vitexin plus verapamil group and of the normal saline group was 44.9 and 39.8 mgÁ min/mL, respectively. Discussion and conclusion: The intestinal first-pass effect of vitexin was considerable, and gastric and hepatic first-pass effects also contribute to the low absolute oral bioavailability of vitexin. The AUC of the vitexin plus verapamil group was slightly higher than that of the vitexin plus normal saline group (by approximately 1.13-fold), suggesting that verapamil does not play an important role in the absorption and secretion of vitexin.

A high-performance liquid chromatography (HPLC) technique was developed for the determination of arctigenin in plasma and various organs of rats after the oral administration of 30, 50 and 70 mgkg(-1) of arctigenin to the Sprague-Dawley rats. Results showed that the validated HPLC method was simple, fast, reproducible and suitable to the determination of arctigenin in rat plasma and organ tissue and one-compartmental model with zero-order absorption process can well describe the changes of arctigenin concentration in the plasma. The concentration of compound was highest in the spleen, less in the liver and the least in the lung.

A high performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination of neomangiferin, mangiferin, timosaponin B III, anemarrhenasaponin I and timosaponin A III in the products of Anemarrhena asphodeloides Bge. processed by different methods. By comparing and analyzing the variation of the contents of the five components, the effects of processing on chemical constituents of Anemarrhena asphodeloides Bge. were explored, which provided evidences for the relevance between processing and the property changes of Anemarrhena asphodeloides Bge. The chromatographic separation was performed on an Alltima C18 column (250 mm x 4.6 mm, 5 microm) with a gradient elution of acetonitrile (A) and 0. 1% formic acid (B) (0 - 10 min, 5% A - 20% A; 10 - 15 min, 20% A - 25% A; 15 -30 min, 25% A - 80% A; 30 -35 min, 80% A - 100% A) at a flow rate of 0.8 mL/min. Neomangiferin and mangiferin were detected by an ultraviolet detector at 265 nm and room temperature. Timosaponin B III, anemarrhenasaponin I and timosaponin A III were detected by an evaporative light scattering detector with the drift temperature at 50 degrees C and gas pressure at 179.1 kPa (26 psi). To some extent, the contents of the major components varied in different processed products of Anemarrhena asphodeloides Bge. The results indicated that different processing methods caused significant differences in the contents of the major components of Anemarrhena asphodeloides Bge. It is of great use for further researching the relevance of the processing methods to pharmacodynamics of Anemarrhena asphodeloides Bge.

Background: Recent research indicates that injections inducing unwanted anaphylactoid reactions occur frequently in a clinical setting. In this paper, we explored anaphylactoid reactions trends in animal models following ginsenosides injections. Methods: Our anaphylactoid animal model was optimized by comparing reactions between BN rats, SD rats, guinea pigs and ICR mice to first intravenous exposure to standard compounds including ovalbumin (OVA), tannic acid (TA), Tween 80 (T80), bovine serum albumin (BSA) and Compound 48/80 (C48/80), Shengmai injection (SMI) and Xuesaitong injection (XSTI) which contains ginsenosides, respectively. The anaphylactoid symptoms were documented and the plasma levels of histamine were assessed. Subsequently, the IgE levels and total complement activity (CH50) were determined to further explore the mechanisms underlying the observed anaphylactoid reactions on the optimized animal model. Results: We observed that BN rats and guinea pigs exhibited particularly exacerbated symptoms after administration of OVA, T80, TA, SMI and XSTI. Regarding histamine levels, we observed that BN rats were more sensitive to TA and XSTI, guinea pigs were more sensitive to OVA, T80 and SMI, and SD rats were more sensitive to C48/80. According to both anaphylactoid symptom scores and histamine secretion rates, BN rats, in particular, were found to be more sensitive to OVA, T80, TA, SMI and XSTI. Noteworthy however, the four rodents showed significantly weaker anaphylactoid reactions after administration of BSA. Conclusion: BN rats were more suitable for comprehensive evaluation of anaphylatoid reactions following injections; both IgE levels and CH50 could be used as auxiliary mediators for the assessment of anaphylactoid reactions.

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