Bioavailability study of berberine and the enhancing effects of TPGS on intestinal absorption in rats.

Berberine chloride (BBR) is a natural isoquinoline alkaloid extracted from medicinal herbs. It has been reported that the intestinal absorption of BBR is very low. In this study, the absolute bioavailability of BBR was studied, and the enhancing effects of D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) on intestinal absorption were investigated in rats. BBR injection was administrated via the femoral vein at a dose of 1.0 mg kg(-1) in intravenous group, and BBR oral formulations were administrated by oral gavage at a dose of 100 mg kg(-1) in BBR control (control) group and BBR-TPGS (test) group, respectively. The result showed that BBR had a very low absolute bioavailability of 0.68%, and TPGS could enhance intestinal absorption of BBR significantly. TPGS at a concentration of 2.5% could improve peak concentration (C(max)) and area under the curve (AUC(0-36)) of BBR by 2.9 and 1.9 times, respectively. The absorption enhancing ability of TPGS may be due to its ability to affect the biological activity of P-glycoprotein and thereby reduce the excretion of absorbed BBR into the intestinal lumen. This study indicated that absolute bioavailability of BBR was 0.68% in rats, and TPGS was a good absorption enhancer capable of enhancing intestinal absorption of BBR significantly.

[Quantitative analysis of four alkaloids in Xianglian preparations by QAMS method].

OBJECTIVE: To examine the feasibilities of the method, quantitative analysis of multi-components by single marker (QAMS) for determination of four alkaloids in Xianglian preparations. METHOD: A HPLC method was developed to determine the contents of four alkaloids, epiberberine, coptisine, palmatine and berberine in Xianglian preparations. Berberine was selected as the internal reference substance, and 3 relative correction factors to berberine were calculated. The contents of the four alkaloids in 16 batches of samples were determined by both external standard method and QAMS. The new method was evaluated by comparing the quantitative results with of the external standard method. RESULT: No significant differences were found between the quantitative results of four alkaloids in 16 batches of samples determined by the two methods. CONCLUSION: QAMS is feasible for determination of four alkaloids simultaneously, and the developed method can be used for quality control of Xiang Lian preparations.

Comparative pharmacokinetics and safety assessment of transdermal berberine and dihydroberberine.

The natural alkaloid berberine has been ascribed numerous health benefits including lipid and cholesterol reduction and improved insulin sensitivity in diabetics. However, oral (PO) administration of berberine is hindered by poor bioavailability and increasing dose often elicits gastro-intestinal side effects. To overcome the caveats associated with oral berberine, we developed transdermal (TD) formulations of berberine (BBR) and the berberine precursor dihydroberberine (DHB). These formulations were compared to oral BBR using pharmacokinetics, metabolism, and general safety studies in vivo. To complete this work, a sensitive quantitative LC-MS/MS method was developed and validated according the FDA guidelines for bioanalytical methods to simultaneously measure berberine, simvastatin, and simvastatin hydroxy acid with relative quantification used for the berberine metabolite demethylene berberine glucuronide (DBG). Acute pharmacokinetics in Sprague-Dawley rats demonstrated a statistically relevant ranking for berberine bioavailability based upon AUC0-8 as DHB TD > BBR TD >> BBR PO with similar ranking for the metabolite DBG, indicating that transdermal administration achieves BBR levels well above oral administration. Similarly, chronic administration (14 days) resulted in significantly higher levels of circulating BBR and DBG in DHB TD treated animals. Chronically treated rats were given a single dose of simvastatin with no observed change in the drugs bioavailability compared with control, suggesting the increased presence of BBR had no effect on simvastatin metabolism. This observation was further supported by consistent CYP3A4 expression across all treatment groups. Moreover, no changes in kidney and liver biomarkers, including alanine aminotransferase and alkaline phosphatase, were observed between treatment formats, and confirming previous reports that BBR has no effect on HMG-CoA expression. This study supports the safe use of transdermal compositions that improve on the poor bioavailability of oral berberine and have the potential to be more efficacious in the treatment of dyslipidemia or hypercholesterolemia.

[Quality analysis and evaluation of Rhizoma Coptidis under different cultivation conditions].

AIM: To develop methods for the fingerprint analysis of Rhizoma Coptidis and the determination of berberine, palmatine and jatrorrhizine in Rhizoma Coptidis, and analyze the contents of these three alkaloids in Rhizoma Coptidis under different cultivation conditions, from different areas and processed with different methods. METHODS: Two methods (HPLC-UV and HPLC-MS) have been developed and used in fingerprint analysis of Rhizoma Coptidis. An HPLC method was used to determine the contents of three alkaloids. RESULTS: With HPLC-MS techniques, seven major chromatographic peaks in the fingerprint analysis of Rhizoma Coptidis were identified by their MS spectra and compared with the reference standards. In different cultivation conditions, shading conditions and growing ages have obvious influence on the contents of three alkaloids in Rhizoma Coptidis, while planting density was not the major factor that influenced the contents of three alkaloids. The contents of three alkaloids of Coptidis samples were almost higher than those of Coptidis reference material. For Coptidis samples from different cultivation area, the contents of these three alkaloids were different greatly. For Coptidis samples processed with different methods, the contents of three alkaloids were not influenced obviously by processing methods. CONCLUSION: The results showed that the ecology cultivation method to replace the traditional shading method was feasible and provided the theoretical foundation for scientifically processing Rhizoma Coptidis.

A series of strategies for solving the shortage of reference standards for multi-components determination of traditional Chinese medicine, Mahoniae Caulis as a case.

In order to solve the bottleneck of reference standards shortage for comprehensive quality control of traditional Chinese medicines (TCMs), a series of strategies, including one single reference standard to determine multi-compounds (SSDMC), quantitative analysis by standardized reference extract (QASRE), and quantitative nuclear magnetic resonance spectroscopy (qNMR) were proposed, and Mahoniae Caulis was selected as an example to develop and validate these methods for simultaneous determination of four alkaloids, columbamine, jatrorrhizine, palmatine, and berberine. Comprehensive comparisons among these methods and with the conventional external standard method (ESM) were carried out. The relative expanded uncertainty of measurement was firstly used to compare their credibility. The results showed that all these three new developed methods can accurately accomplish the quantification by using only one purified reference standard, but each of them has its own advantages and disadvantages as well as the specific application scope, which were also discussed in detail in this paper.

[Berberine Hydrochloride Reference Standard (Control 001) of National Institute of Health Sciences].

The raw material of Berberine Hydrochloride was examined for preparation of the "Berberine Hydrochloride Reference Standard". The analytical data obtained were: UV spectrum: lambda max, 420, 345, 263 and 228 nm and specific absorbance (E1ca1%) in ethanol at each lambda max, 155, 724, 796 and 820, respectively; IR spectrum, specific absorptions at 2844, 1635, 1569, and 1506 cm-1; and the spectrum of raw material was consistent with that of Standard (Control 941). Also, thin-layer chromatography, an impurity was detected; high-performance liquid chromatography, several impurities were detected. The amount of each impurity was estimated at less than 0.1% and the total amount of impurities was less than 0.2%. Based on the above results, the candidate material was authorized as the Berberine Hydrochloride Reference Standard (Control 001) of the National Institute of Health Sciences.

[Berberine hydrochloride reference standard (Control 941) of the National Institute of Health Sciences].

The raw material of berberine hydrochloride was examined for preparation of the "Berberine Hydrochloride Reference Standard". The candidate material was evaluated physico-chemically by a collaborative study in which five laboratories participated. Analytical data obtained were as follows: UV spectrum, lambda max = 228, 263, 345, and 421 nm and specific absorbance E1%1cm at each lambda max = 814, 794, 722, and 160, respectively; IR spectrum, specific absorption wave numbers at 2845, 1633, 1568, and 1506 cm-1; thin-layer chromatography, some laboratories detected a trace amount of one or two spot and others not detected; high-performance liquid chromatography, 2-5 impurities were detected and the amount of any impurities were estimated to be less than 0.05% and the total amount less than 0.2%. Based on the above results, the candidate material was authorized as the Berberine Hydorochloride Reference Standard of National Institute of Health Sciences.