Absorption Of Berberine Research Articles

Cytotoxic and epigenetic effects of berberine-loaded chitosan/pectin nanoparticles on AGS gastric cancer cells: Role of the miR-185-5p/KLF7 axis, DNMTs, and global DNA methylation

Poor bioavailability, solubility, and absorption of berberine (Ber) limit its widespread application. Here, we formulated novel chitosan/pectin nanoparticles (NPs) loaded with Ber to address delivery problems and promote the anticancer properties of Ber in AGS gastric cancer cells. The ionic gelification method was used to synthesize NPs-Ber. Physicochemical characterization of NPs-Ber was performed using FE-SEM, DLS, PDI, ζ potential, and FTIR. The cytotoxic effects of NPs-Ber on AGS cells were evaluated using the MTT assay. Apoptosis and cell cycle arrest were examined by flow cytometry. The gene expression levels of miR-185-5p, KLF7, caspase-3, and DNMTs were determined using RT-qPCR. In addition, the 5-methylcytosine level in the genomic DNA was quantified using ELISA. FE-SEM images revealed a denser and more packed matrix for NPs-Ber, and FTIR analysis confirmed the formation of NPs-Ber. The size (550.39 nm), PDI (0.134), and ζ potential (−16.52 mV) confirmed the stability of the prepared NPs-Ber. NPs-Ber showed a continuous release pattern following the Korsmeyer-Peppas model such that 81.36 % of Ber was released from the formulation after 240 min. Compared to NPs and free Ber, NPs-Ber was found to possess higher anticancer activity in AGS cells. This result was indicated by the viability test and further clarified by augmented apoptosis and cell cycle arrest at the G0/G1 phase. The IC50 value of NP-Ber against AGS cells was significantly lower than those of free Ber and NPs. Interestingly, our results showed that NPs-Ber considerably changed the expression levels of miR-185-5p, KLF7, caspase-3, and DNMTs (DNMT1, 3A, and 3B) compared with unloaded NPs and free Ber. Additionally, 5-methylated cytosine (5-mC) levels in cells treated with NPs-Ber were significantly higher than those in cells treated with unloaded NPs or free Ber. In summary, the present study demonstrated that Ber encapsulation in NPs enhances its cytotoxic and epigenetic effects on AGS cells, suggesting the promising potential of NPs-Ber in GC therapy.

DSPE-PEG polymer enhanced berberine absorption specifically in the small intestine of rats through paracellular passway.

This study focuses on investigating the potential impact of DSPE-PEG polymers on intestinal absorption and related mechanism of berberine in rats. Effect of DSPE-PEG polymer on intestinal absorption of berberine was investigated with an in situ closed-loop method in rats. To confirm the safety of DSPE-PEG polymer, morphological observation of rat intestine and measurement of biological markers in the intestinal perfusion of rats was performed. Underling mechanism behind promoting action of DSPE-PEG polymer was explored from its impact on the P-gp function and tight junction using in vitro diffusion chamber system, Caco-2 monolayer cells and western blot. DSPE-PEG polymer demonstrated significant enhancement action on the berberine absorption in rats without any obvious membrane toxicity. DSPE-PEG polymer (1.0%, w/v) induced the most significant promoting effect on berberine absorption specifically in the small intestine of rats. Results of mechanistic studies revealed that DSPE-PEG polymer might not regulate intestinal P-gp function, but significantly down-regulated the expression of tight junction-related proteins, which accordingly led to loosening the tight junctions of intestinal epithelium cells, and consequently increased paracellular absorption of berberine in rats. DSPE-PEG polymer, as an excellent absorption enhancer, seems very promising in increasing oral bioavailability of berberine.

Evaluation of Intestinal Drug Absorption and Interaction Using Quadruple Single-Pass Intestinal Perfusion Coupled with Mass Spectrometry Imaging.

Visualization and characterization of the intestinal membrane transporter-mediated drug absorption and interaction are challenging due to the complex physical and chemical environment. In this work, an integrated strategy was developed for in situ visualization and assessment of the drug absorption and interaction in rat intestines using quadruple single-pass intestinal perfusion (Q-SPIP) technique coupled with matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI). Compared with the traditional SPIP only available for perfusion of one single intestinal segment, the Q-SPIP model can simultaneously perfuse four individual segments of each rat intestine (duodenum, jejunum, ileum, and colon), enabling to obtain rich data from one rat. Subsequently, the drug distribution and absorption in rat intestinal tissue were accurately visualized by using an optimized MALDI MSI approach. The utility and versatility of this strategy were demonstrated via the examination of P-glycoprotein (P-gp)-mediated intestinal absorption of berberine (BBR) and its combination with natural products possessing inhibitory potency against P-gp. The change in the spatial distribution of BBR was resolved, and MALDI results showed that the signal intensity of BBR in defined regions was enhanced following coperfusion with P-gp inhibitors. However, enhanced absorption of BBR after coperfusion with the P-gp inhibitor was not observed in the ulcerative colitis rat model, which may be due to the damage to the intestinal barrier. This study exemplifies the availability and utility of Q-SPIP coupled with MALDI MSI in the examination of transporter-mediated intestinal drug absorption and interaction for fundamental inquiries into the preclinical prediction of oral absorption and drug interaction potential.

Emulsification by vitamin E TPGS or Quillaja extract enhanced absorption of berberine without affecting its metabolism in humans.

Berberine is widely used for the prevention of cancers and diabetes. However, the absorption rate of berberine is less than 1% in humans. The objective of this research was to determine whether emulsification improves the absorption and affects the metabolism of orally ingested berberine. Twelve healthy subjects, both men and women, received 800 mg berberine in a powder or emulsified form by vitamin E TPGS or Quillaja extract using a randomized crossover design. Blood samples were collected 12 hours after a dose. Berberine and its metabolites in plasma were analyzed with and without hydrolysis by glucuronidase and sulfatase on UHPLC-MS/MS. The area under the curve (AUC0-12 h) and peak plasma concentration (Cmax) of berberine was 6.7 nM h and 0.9 nM in participants who received berberine powder. They were increased to 12.6 nM h and 2.0 nM by TPGS emulsification and 28.0 nM h and 5.1 nM by Quillaja extract emulsification, respectively. Berberrubine and demethyleneberberine were detected as major phase-1 metabolites of berberine. The AUC0-12 of both free and total berberrubine was significantly increased by TPGS and Quillaja extract. Emulsification by Quillaja extract was more effective than TPGS to increase the plasma concentrations of free and total demethyleneberberine. However, the ratios of phase-1 metabolites and ratios of phase-2 conjugates were not affected by emulsification. Absorption increases of berberine by TPGS or Quillaja extract emulsification may lead to enhanced bioactivity in humans.

Emulsification by TPGS or Quillaja Extract Increased Absorption and Affected Metabolism of Berberine in Humans

Abstract Objectives Berberine is a botanical alkaloid used widely for the prevention of several diseases. However, the absorption rate of berberine is less than 1% in human. The objectives of this study were to determine whether emulsification by TPGS or Quillaja extract affect the absorption and metabolism of orally ingested berberine in human volunteers. Methods Twelve healthy subjects (7 male and 5 females, 21–50-year-old) participated this study. Each subject received 800 mg berberine in a powder form or emulsified with TPGS or Quillaja extract using a randomized crossover design with one-week washout period. Blood samples were collected at 0, 0.5, 1, 2, 3, 4, 6, 8, and 12 hours after dose. Plasma was hydrolyzed with glucuronidase and sulfatase before total content of berberine and its metabolites were analyzed on LC/MS/MS. Free forms of metabolites were determined in plasma without hydrolysis. Pharmacokinetic parameters were calculated using a non-compartment model before they were compared by analysis of covariance. Results The area under the curve (AUC) and peak plasma concentration (Cmax) of berberine was 6.6 μM.hr and 0.9 μM in participants received berberine powder. They were increased to 18.3 μM.hr and 4.5 μM by TPGS emulsification and 28 μM.hr and 5.1 μM by Quillaja extract emulsification, respectively. Berberrubine and demethylberberine were major metabolites of berberine. The AUC of free Berberrubine and demethylberberine was increased by 1.9 fold and 1.6 fold by TPGS and 5.9 folds and 2.7 folds by Quillaja extract, respectively, compared to berberine powder. Participants received berberine powder had AUC of 254 μM.hr and Cmax of 33 μM for total berberrubine. TPGS emulsification increased these values to 425 μM.hr and 54 μM, while Quillaja extract increased them to 341 μM.hr and 44 μM, respectively. Significant increases of AUC and Cmax were also observed for total demethylberberine by TPGS or Quillaja extract emulsification. Conclusions Emulsification of berberine with TPGS or Quillaja extract significantly increased the absorption of berberine and its metabolites in human compared to berberine supplement without emulsifiers. Funding Sources Florida High Tech Corridor Council and Designs for Health.

Berberine as a chemical and pharmacokinetic marker of the butanol-extracted Food Allergy Herbal Formula-2

RationaleFood Allergy Herbal Formula-2 (FAHF-2) provided protection against peanut anaphylaxis in a murine model and induced beneficial immune-modulation in humans. Butanol-refined FAHF-2, B-FAHF-2, retained safety and efficacy in the peanut allergic murine model at only 1/5 of FAHF-2 dosage. One compound, berberine, was isolated and identified in vitro as a bioactive component present in FAHF-2 and B-FAHF-2. The aim of this study was to investigate berberine as a chemical and pharmacokinetic marker of B-FAHF-2. MethodsThe consistency of constituents between B-FAHF-2 and FAHF-2 was tested. Peanut allergic C3H/HeJ mice were orally administered with 1mg of berberine or B-FAHF-2 containing an equivalent amount of berberine, and the ability to protect against peanut anaphylaxis and pharmacokinetic parameters were determined. Human intestinal epithelial cells (Caco-2) were cultured with berberine with or without the nine individual herbal constituents in B-FAHF-2, and the absorbed berberine levels were determined. ResultsBerberine is one of the major components in B-FAHF-2 and FAHF-2 formula. In a peanut allergic mouse model, B-FAHF-2, but not berberine, protected mice from anaphylaxis reactions. Pharmacokinetic profiles showed that the Cmax of B-FAHF-2 fed mice was 289.30±185.40ng/mL; whereas berberine alone showed very low bioavailability with Cmax value of 35.13±47.90ng/mL. Caco-2 cells influx assay showed that 7 of 9 herbal constituents in B-FAHF-2 increased berberine absorption at rates ranging from 18 to 205%. ConclusionsB-FAHF-2 remarkably increased the bioavailability of berberine. Berberine can be used as chemical and pharmacokinetic marker of B-FAHF-2. Other herbal components in B-FAHF-2 may facilitate the absorption of berberine.

Formulation Design and In vitro Evaluation of Berberine- Loaded Self-Nanoemulsifying Drug Delivery System

Purpose : To improve the oral bioavailability of berberine using a new self-nanoemulsifying drug delivery system (SNEDDS). Methods : Berberine SNEDDS was designed using solubility studies and phase diagram construction. A series of tests were carried out to study the effect of oil content, dilution, and drug loading on particle size. The morphology of the nanoemulsion was examined with a transmission electron microscope. Subsequently, the optimized berberine SNEDDS was investigated for in vitro release and compared with two marketed products (Xiaowei capsules and Beike tablets) Results : The optimized formulation, composed of berberine of 6.0 %, castor oil of 18.8 %, Tween 20 of 37.6 %, and glycerol of 37.6 %, gave a mean particle size of approximately 60 nm, and was not affected by dilution. The optimized formulation released 90 % berberine in 20 min, while the reference products, Xiaowei capsules and Beike tablets, required 2 h to release 90 % of berberine. Conclusion : The optimized formulation of SNEDDS is a potential alternative oral dosage form for improving oral absorption of berberine. Keywords : Berberine, Pseudoternary phase diagram, Self-nanoemulsifying, SNEDDS, Drug release

Poor permeability and absorption affect the activity of four alkaloids from Coptis.

Coptidis rhizoma (Coptis) and its alkaloids exert various pharmacological functions in cells and tissues; however, the oral absorption of these alkaloids requires further elucidation. The present study aimed to examine the mechanism underlying the poor absorption of alkaloids, including berberine (BER), coptisine (COP), palmatine (PAL) and jatrorrhizine (JAT). An ultra‑performance liquid chromatography (UPLC) method was validated for the determination of BER, COP, PAL and JAT in the above experimental medium. In addition, the apparent oil‑water partition coefficient (Po/w); apparent permeability coefficient (Papp), determined using a parallel artificial membrane permeability assay (PAMPA) plate; membrane retention coefficient (R %); and effect of P‑glycoprotein (P‑gp) inhibitor on the Papp of the four alkaloids were investigated. The intestinal absorption rate constant (Ka) and absorption percentage (A %) of the four alkaloids were also determined. The results of the present study demonstrated that the Po/w of the four alkaloids in 0.1 mol·l‑1 HCl medium was significantly higher (P<0.01), compared with those of the alkaloids in phosphate buffer (pH 7.4). The Papp of BER was 1.0‑1.2x10‑6 cm·s‑1, determined using a PAMPA plate, and the Papp of BER, COP, PAL and JAT decreased sequentially. The concentrations of the four alkaloids on the apical‑to‑basolateral (AP‑BL) surface and the basolateral‑to‑apical (BL‑AP) surface increased in a linear manner, with increasing concentrations between 10 and 100 µmol. In addition, the transportation of BER on the BL‑AP surface was significantly faster (P<0.01), compared with that on the AP‑BL surface and, following the addition of verpamil (a P‑gp inhibitor), the Papp (AP‑BL) of the four alkaloids increased, whereas the Papp (BL‑AP) was significantly decreased (P<0.01). The rat intestinal perfusion experiment demonstrated that the four alkaloids were poorly absorbed; however, the Ka of BER was significantly higher, compared with the three other alkaloids. Furthermore, the A % and Ka provided evidence that the absorption of BER was increased in the jejunum, compared with in the ileum. In conclusion, the four alkaloids from Coptis appeared to be poorly absorbed, determined using a shake flask, pre‑coated PAMPA plates, a Caco‑2 cell monolayer model and intestinal perfusion; however, absorption was higher in the jejunum than in the ileum. Among the four alkaloids, the permeability of BER was markedly higher than the others, and P‑gp efflux had a significant effect on the absorption of those alkaloids.

New Oral Delivery System to Improve Absorption of Berberine: Likely Interaction of Cationized Chitosan with PG-P Pump.

Berberine Chloride (BC) is an isoquinolinic alkaloid that is extracted from plants of generis Berberis. During the last decade, researchers and clinicians have paid increasing attention to BC, because of its impressive hypoglycemic and blood lipids lowering properties. Several clinical studies gave proof of evidence regarding BC efficacy in humans and pharmacological mechanisms of action, related to the previously mentioned activities, have been proposed and substantially confirmed. On the other side, BC shows a very poor oral bioavailability mainly because of the interaction with P-Glycoprotein (Pg-P) pump, which extrudes BC from inside to outside of the enteric cell. This paper describes a novel oral delivery system containing a Chitosan-N-AcetylCystein salt capable to interact with Pg-P, partially inhibiting BC extruding process. Preliminary data confirming the aforementioned postulated mechanism on Caco-2 in vitro model have been herewith reported and discussed.

Intestinal absorption of berberine and 8-hydroxy dihydroberberine and their effects on sugar absorption in rat small intestine

The intestinal absorption of berberine (Ber) and its structural modified compound 8-hydroxy dihydroberberine (Hdber) was compared, and their effects on the intestinal absorption of sugar by perfusion experiment were investigated in order to reveal the mechanism of low dose and high activity of Hdber in the treatment of hyperglycemia. The absorption of Hdber and Ber in rat small intestine was measured by in situ perfusion. High performance liquid chromatography (HPLC) was used to determine the concentrations of Hdber and Ber. In situ perfusion method was also used to study the effects of Hdber and Ber on sugar intestinal absorption. Glucose oxidase method and UV spectrophotometry were applied to examine the concentrations of glucose and sucrose in the perfusion fluid. The results showed that the absorption rate of Ber in the small intestine was lower than 10%, but that of Hdber was larger than 70%. Both Hdber and Ber inhibited the absorption of glucose and sucrose at the doses of 10 and 20 μg/mL. However, Hdber presented stronger activity than Ber (P<0.01). It is suggested that Hdber is absorbed easily in rat small intestine and that its inhibitory effect on the absorption of sugar is better than Ber.

Characterization, pharmacokinetics, and hypoglycemic effect of berberine loaded solid lipid nanoparticles

The high aqueous solubility, poor permeability, and absorption of berberine (BBR) result in its low plasma level after oral administration, which greatly limits its clinical application. BBR solid lipid nanoparticles (SLNs) were prepared to achieve improved bioavailability and prolonged effect. Developed SLNs showed homogeneous spherical shapes, small size (76.8 nm), zeta potential (7.87 mV), encapsulation efficiency (58%), and drug loading (4.2%). The power of X-ray diffraction combined with 1H nuclear magnetic resonance spectroscopy was employed to analyze chemical functional groups and the microstructure of BBR-SLNs, and indicated that the drug was wrapped in a lipid carrier. Single dose (50 mg/kg) oral pharmacokinetic studies in rats showed significant improvement (P<0.05) in the peak plasma concentration, area under the curve, and variance of mean residence time of BBR-SLNs when compared to BBR alone (P<0.05), suggesting improved bioavailability. Furthermore, oral administration of both BBR and BBR-SLNs significantly suppressed body weight gain, fasting blood glucose levels, and homeostasis assessment of insulin resistance, and ameliorated impaired glucose tolerance and insulin tolerance in db/db diabetic mice. BBR-SLNs at high dose (100 mg/kg) showed more potent effects when compared to an equivalent dose of BBR. Morphologic analysis demonstrated that BBR-SLNs potentially promoted islet function and protected the islet from regeneration. In conclusion, our study demonstrates that by entrapping BBR into SLNs the absorption of BBR and its anti-diabetic action were effectively enhanced.

Separation of choline from Coptidis Rhizoma and impact on glucose metabolism of berberine in HepG2 cells

To investigate action of hydrophilic constituents from Coptidis Rhizoma on glucose-lowering effect metabolism of berberine in HepG2 cells. Hydrophilic fractions of Coptidis Rhizoma were prepared by high speed counter current chromatography and separated by silica gel column chromatography. MTT assay was used to monitor the proliferation of HepG2 cells, and Kit was used to test the glucose consumption in culture solution. Choline was separated from Coptidis Rhizoma for the first time. Cell assay showed choline can significantly increase the glucose lowering effect of berberine and improve the cytotoxicity of berberine within test concentration. Compared with same dose of berberine, berberine 38 mg x L(-1) in combination with choline 100 mg x L(-1) can make glucose consumption increase by 34% and elevate cell livability up to 75% in HepG2 cells. The results suggest that choline had a synergistic effect on improving glucose absorption of berberine and decreasing cytotoxicity of berberine.

Berberine increases the expression of NHE3 and AQP4 in sennosideA-induced diarrhoea model

Berberine, a compound isolated from Chinese Goldthread Rhizome, has been widely used as a non-prescription drug to treat diarrhoea in China. Previous studies have demonstrated multiple pharmacological activities for berberine, including its significant role in antimicrobial activity. However, its effect on ion exchange and water transfer remains unclear. The present study aims to explore the effect of berberine on the expression of Na+/H+ exchanger3 (NHE3) and aquaporin4 (AQP4) in both diarrhoea mouse model induced by sennosideA and human intestinal epithelium cell line (HIEC). Semi-quantitative RT-PCR, immunohistochemistry and western blotting were adopted to detect the mRNA and protein expression levels of NHE3 and AQP4. Furthermore, the absorption of berberine and the PKC activity were detected by HPLC and PepTag® Assay to elucidate the underlying mechanisms. It was shown that the expression levels of NHE3 and AQP4 were significantly increased in the diarrhoea mice treated with berberine compared with the untreated diarrhoea mice. Similarly, the expression levels of NHE3 and AQP4 were strikingly enhanced in HIEC co-treated with sennosideA and berberine compared with samples treated with sennosideA only. We also found the maximal absorption of berberine to be approximately 0.01%. In addition, no significant change of PKC activity was observed in the different HIEC treated groups. These results showed that berberine was able to increase the expression of NHE3 and AQP4, suggesting that berberine might exhibit its anti-diarrhoeal effect partially by enhancing the absorption of Na+ and water.

Studies on intestinal absorption of alkaloids in Coptis chinensis by in situ single-pass perfused rat intestinal model

To study the absorption characteristics of alkaloids in Coptis chinensis in rat intestinal. In situ single-pass perfused rat intestinal model was used and the concentrations of berberine and palmatine were determined by HPLC, the drug absorption rate constant (K(a)) and apparent absorption coefficient (P(app)) were tested to evaluate their absorption characteristics. The absorption of berberine and palmatine in different regions of rat intestinals was significantly different. From bigness to smallness, the P(app) value of berberine at 50 mg x L(-1) were ileum, duodenum, jejunum and colon, of palmatine at 50 mg x L(-1) were ileum, colon, jejunum and duodenum. The concentration of berberine and palmatine had distinctive effect on the K(a) value of berberine and palmatine were ordered from larger to little as in Wujiwan compatibility, Coptis chinensis extractive and single compound. The berberine and palmatine were absroped at all regions of rat intestinal. The absorption characteristics of 2 alkaloids were not passive diffusion. The other ingredients in Wujiwan compatibility and Coptis chinensis extractive could promote the absorption of alkaloids.

In-vivo studies on the pharmacokinetics of berberine on middle cerebral artery occlusion rat and sham-operated rat

The present study aims to investigate the influence of cerebrovascular disease and herb prescription on the pharmacokinetics of berberine. In the designed study, rats were divided into middle cerebral artery occlusion (MCAO) group and sham-operated group. Each group contained two subgroups: Oral administration of Huang-Lian-Jie-Du-Tang (HLJDT) (is equal to 258 mg berberine/kg body weight) and pure berberine (is equal to 258 mg berberine/kg body weight, too). The pharmacokinetics of berberine following oral administration of pure berberine or Huang-Lian-Jie-Du-Tang (HLJDT) investigated in MCAO and sham-operated rats were compared. The pharmacokinetics results indicated that both in the two groups, the AUC and Cmax of berberine in HLJDT group were larger than in pure berberine group. Besides, the absorption of berberine in MCAO group was obviously better and the metabolic rate of berberine was slower than in sham-operated group. The authors inferred that the cerebrovascular disease and prescription of HLJDT has increased the bioavailability of berberine in-vivo. It noticed that the better absorption of berberine would be in favor of berberine to exert pharmacological effects on cerebrovascular disease. In this sense, it is necessary to take the pharmacokinetics characteristics of berberine in different conditions into consideration in clinics. This study may give an advice for further herbal research which will be carried on the same subject. Key words: Huang-Lian-Jie-Du-Tang, berberine, pharmacokinetics, middle cerebral artery occlusion (MCAO), compatibility.

Enhancing effects of chitosan and chitosan hydrochloride on intestinal absorption of berberine in rats

Berberine chloride (BBR) is a plant alkaloid that has been used for centuries for treatment of inflammation, dysentery, and liver diseases. It is poorly absorbed from the gastrointestinal (GI) tract and its various clinical uses are limited because of its poor bioavailability. The object of the present study was to investigate the absorption enhancing effect of chitosan on BBR. Mixtures of BBR and chitosan were prepared and the absorption enhancement was investigated in rats. The results showed a dose-dependent absorption enhancement produced by chitosan. Formulations containing 0.5%, 1.5%, and 3.0% chitosan resulted in improvement of AUC0–36 h values by 1.9, 2.2, 2.5 times. The absorption enhancing ability of chitosan may be due to its ability to improve the BBR paracellular pathway in the intestinal tract. Chitosan hydrochloride, a salt of chitosan, was also investigated in this study. However, the addition of 2.0% and 3.3% chitosan hydrochloride to BBR solution did not produce any increase in either Cmax or AUC0–36 h of BBR. Subsequent solubility studies suggested that the reduced berberine chloride solubility in chitosan hydrochloride may limit the enhancement ability. This study showed that the optimum formulation producing the highest BBR absorption is the BBR solution containing 3.0% chitosan.

In situ intestinal absorption kinetics of berberine and jatrorrhizine fromextractive Rhizoma Coptidis in rats

To investigate the in situ absorption kinetics of berberine (BER) and jatrorrhizine( JAT) at different intestine segments in rats. The intestinal perfusion experiment was performed on rats in vivo to observe the effects of absorption sites and drug concentration on the intestinal absorption characteristics of BER and JAT. The apparent absorption rate constants (Ka) of BER and JAT at duodenum, jejunum, ileum and colon were 0.1540, 0.1160, 0.9793, 0.6795 h(-1) and 0.0743, 0.0564, 0.0456, 0.0234 h(-1), respectively. The absorption of BER and JAT decreased according to the turn of duodenum, jejunum, ileum and colon. Compared to the lower segment, BER and JAT were better absorbed at the upper and middle segments of intestine in rats. The Ka of BER and JAT had no significant difference when the concentration of the extractive Rhizoma Coptidis was at 22-88 mg x L(-1). However, the absorption quantity of BER and JAT were proportional to the concentration respectively and the saturated phenomena were not observed. Both the BER and the JAT is can be absorbed in whole intestine and the results indicated that the absorption of BER and JAT compiled with the first order kinetics through passive diffusion mechanism.

Enhancement of sodium caprate on intestine absorption and antidiabetic action of berberine.

Berberine, a plant alkaloid used in traditional Chinese medicine, has a wide spectrum of pharmacological actions, but the poor bioavailability limits its clinical use. The present aim was to observe the effects of sodium caprate on the intestinal absorption and antidiabetic action of berberine. The in situ, in vitro, and in vivo models were used to observe the effect of sodium caprate on the intestinal absorption of berberine. Intestinal mucosa morphology was measured to evaluate the toxic effect of sodium caprate. Diabetic model was used to evaluate antidiabetic effect of berberine coadministered with sodium caprate. The results showed that the absorption of berberine in the small intestine was poor and that sodium caprate could significantly improve the poor absorption of berberine in the small intestine. Sodium caprate stimulated mucosal-to-serosal transport of berberine; the enhancement ratios were 2.08, 1.49, and 3.49 in the duodenum, jejunum, and ileum, respectively. After coadministration, the area under the plasma concentration-time curve of berberine was increased 28% than that in the absence of sodium caprate. Furthermore, both berberine and coadministration with sodium caprate orally could significantly decrease fasting blood glucose and improve glucose tolerance in diabetic rats (P < 0.05). The hypoglycemic effect of coadministration group was remarkably stronger, and the areas under the glucose curves was decreased 22.5%, compared with berberine treatment group (P < 0.05). Morphologic analysis indicated that sodium caprate was not significantly injurious to the intestinal mucosa. The study demonstrates that sodium caprate could significantly promote the absorption of berberine in intestine and enhance its antidiabetic effect without any serious mucosal damage.

The Involvement of P‐Glycoprotein in Berberine Absorption

Berberine is an important ingredient in a number of traditional Chinese medicines but has been shown to have poor bioavailability in the dog. The aim of this study was to use the P-glycoprotein (P-glycoprotein) inhibitors cyclosporin A, verapamil and the monoclonal antibody C219 in in vivo and in vitro models of intestinal absorption to determine the role of P-glycoprotein in berberine absorption. In the rat recirculating perfusion model, berberine absorption was improved 6-times by P-glycoprotein inhibitors. In the rat everted intestinal sac model, berberine serosal-to-mucosal transport was significantly decreased by cyclosporin A. In Ussing-type chambers, the rate of serosal-to-mucosal transport across rat ileum was 3-times greater than in the reverse direction and was significantly decreased by cyclosporin A. In Caco-2 cells, berberine uptake was significantly increased by P-glycoprotein inhibitors and by monoclonal antibody C219. P-glycoprotein appears to contribute to the poor intestinal absorption of berberine which suggests P-glycoprotein inhibitors could be of therapeutic value by improving its bioavailability.

Chitosan hydrogel as a base for transdermal delivery of berberine and its evaluation in rat skin.

Berberine is the main ingredient of Coptis spp. This study selected berberine as a model drug to design a transdermal delivery system for the treatment of cutaneous leishmaniasis. Berberine was incorporated into chitosan hydrogel to prepare ointments. The physicochemical properties of the ointments and the release profile of berberine were investigated. The results indicated that the viscosity of chitosan hydrogel increased with an increasing amount of lactic acid or EDTA. The effect of EDTA on the viscosity was greater than that of lactic acid. By differential scanning calorimetry (DSC) measurement, no interaction was found to occur between chitosan and the soluble berberine. The release rate of berberine was inversely proportional to ointment viscosity. In in vitro skin perfusion studies, only trace amounts of berberine permeated through the rat skin due to its low oil-water partition coefficient. Surfactants were used as penetration enhancers to increase the percutaneous absorption of berberine. Among the enhancers, benzalkonium chloride was found to be the most efficient. Additionally, Tween 80 could increase the loading amount of berberine in the skin.