Effects of berberine on intracellular free calcium in smooth muscle cells of Guinea pig colon

Berberine inhibits intracellular Ca2+ signals in mouse pancreatic acinar cells through M3 muscarinic receptors: Novel target, mechanism, and implication

Berberine, a natural isoquinoline alkaloid, exhibits a variety of pharmacological effects, but the pharmacological targets and mechanisms remain elusive. Here, we report a novel finding that berberine inhibits acetylcholine (ACh)-induced intracellular Ca2+ oscillations, mediated through an inhibition of the muscarinic subtype 3 (M3) receptor. Patch-clamp recordings and confocal Ca2+ imaging were applied to acute dissociated pancreatic acinar cells prepared from CD1 mice to examine the effects of berberine on ACh-induced Ca2+ oscillations. Whole-cell patch-clamp recordings showed that berberine (from 0.1 to 10 µM) reduced ACh-induced Ca2+ oscillations in a concentration-dependent manner, and this inhibition also depended on ACh concentrations. The inhibitory effect of berberine neither occurred in intracellular targets nor extracellular cholecystokinin (CCK) receptors, chloride (Cl-) channels, and store-operated Ca2+ channels. Together, the results demonstrate that berberine directly inhibits the muscarinic M3 receptors, further confirmed by evidence of the interaction between berberine and M3 receptors in pancreatic acinar cells.

Pingkui Enema Alleviates TNBS-Induced Ulcerative Colitis by Regulation of Inflammatory Factors, Gut Bifidobacterium, and Intestinal Mucosal Barrier in Rats

Background

Ulcerative colitis (UC) is a chronic recurrent inflammation of the colon, and clinical outcome of UC is still unsatisfied. Pingkui enema, a traditional Chinese medicine prescription, has been safely applied for the treatment of diarrhea and dysentery in clinic for many years. However, its mechanism is still elusive. The present study is designed to investigate the effect of Pingkui enema on trinitrobenzene sulfonic acid- (TNBS-) induced ulcerative colitis (UC) and possible mechanism in rats.

Methods

UC was induced by intracolonic instillation of TNBS in male Sprague-Dawley rats, which were treated with different dosages of Pingkui enema (low, medium, and high) or sulfasalazine for ten days. Survival rate was calculated. A clinical disease activity score was evaluated. Histological colitis severity was analyzed by hematoxylin-eosin (HE) staining. Content of Bifidobacterium in intestinal tissue was analyzed by RT-PCR. Concentration of IL-8, IL-13, TNF-α, D-lactic acid (D-LA), and diamine oxidase (DAO) in serum and contents of adhesin and receptor of Bifidobacterium adhesion in rat intestinal mucus were measured by ELISA.

Results

The results showed that Pingkui enema treatment with high dosage markedly improved the survival rate compared with untreated and sulfasalazine treated groups. All dosages of Pingkui enema reduced pathological score. High dosage of Pingkui enema and sulfasalazine treatments significantly reduced the serum concentration of IL-8, TNF-α, D-LA, and DAO and markedly increased the serum concentration of IL-13. In addition, high-dose Pingkui enema and sulfasalazine treatments increased gut content of Bifidobacterium, gut mucus expressions of adhesin, and adhesin receptor of Bifidobacterium.

Conclusions

Pingkui enema has therapeutic effect on TNBS-induced UC, and possible mechanism may be via regulation of gut probiotics (Bifidobacterium) and inflammatory factors and protection of intestinal mucosal barrier.

Pharmacological and therapeutic effects of Berberis vulgaris and its active constituent, berberine

Barberry (Berberis vulgaris L. family Berberidaceae) is well known in Iran and various parts of this plant including its root, bark, leaf and fruit have been used as folk medicine. The two decades of research has demonstrated different pharmacological and therapeutic effects of B. vulgaris and its isoquinoline alkaloids (particularly berberine). Studies carried out on the chemical composition of the plant show that the most important constituents of this plant are isoquinoline alkaloids such as berberine, berbamine and palmatine. Berberine represents one of the most studied among the naturally occurring protoberberine alkaloids. In addition to B. vulgaris (barberry), berberine is present in many other plants and is used for the treatment of different diseases. This article reviews the traditional uses and pharmacological effects of total extract and the most active ingredient of B. vulgaris (berberine).

Comparison of two Chinese medical herbs, Huangbai and Qianniuzi, on influence of short circuit current across the rat intestinal epithelia

Huangbai (Phellodendron spec.) and Qianniuzi (Pharbitis spec.) are two traditional Chinese medical herbs used for anti-diarrheal and laxative agents, respectively. Ethanol and water extracts of these two herbs were prepared and effects of the extracts on ion transport of the rat intestinal epithelia were studied. For measuring changes of the short circuit current across the epithelia, the rat intestinal epithelia were mounted in the Ussing chamber and attached with voltage/current clamp. The intestinal epithelia were firstly activated by serosal administration of 5 microM forskolin. As current raised and being stable, extracts of these herbs were added, respectively, and changes in the short circuit current were recorded. Ethanol extract of Huangbai attenuated the current increment; on the contrary, ethanol extract of Qianniuzi augmented the current increment additionally. Water extracts of the two herbs showed minor effects on the current in comparison to ethanol extracts. The results provide evidences to reveal the pharmacological mechanism of the two Chinese medical herbs on the intestinal tissue.

Effect of Ethanol Extracts of Three Chinese Medicinal Plants With Anti-diarrheal Properties on Ion Transport of the Rat Intestinal Epithelia

Effects of ethanol extracts of three Chinese medicinal plants, namely, Qinpi (Fraxini cortex), Kushen (Sophora flavescens, AITON), and Huanglian (Coptis teeta, WALLICH), on ion transport of the rat intestinal epithelia were determined in this study. Rat intestinal epithelia mounted in an Ussing chamber attached to a voltage/current clamp were used for measuring changes in the short circuit current across the epithelia. Activation of the intestinal epithelia by serosal administration of 5 microM forskolin resulted in an increase in basal short circuit current. The ethanol extracts of each of the three plants partially reduced the current stimulated by forskolin. In the following experiments, ouabain and bumetanide were added prior to adding the ethanol extract of these plants for revealing their effect on Na(+) and Cl(-) movement. The results suggest that the ethanol extract of the Qinpi would affect Cl(-) transport. On the contrary, the ethanol extract of Kushen would affect Na(+) transport rather than Cl(-) movement. This study provides evidences that reveal the pharmacological mechanism of the Chinese plants with anti-diarrheal properties.

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Involvement of p38 mitogen-activated protein kinase in the induction of interleukin-12 p40 production in mouse macrophages by berberine, a benzodioxoloquinolizine alkaloid

Interleukin (IL)-12 plays a pivotal role in the development of T helper type 1 (Th1)-immune response, which may have therapeutic effects on diseases associated with pathologic Th2 responses such as allergic disorders and asthma. In this study, we investigated the effects of berberine, a benzodioxoloquinolizine alkaloid with anti-microbial and anti-tumor activities, on the production of IL-12 p40, an inducible subunit of IL-12, in mouse macrophages. Berberine-induced IL-12 p40 production and activation of p38 mitogen-activated protein kinase (MAPK) in dose-dependent manners, which were significantly inhibited by p38 MAPK inhibitors and yohimbine, indicating that p38 MAPK and alpha(2)-adrenergic receptor were involved in the induction of IL-12 p40 production in mouse macrophages by berberine. Furthermore, berberine significantly enhanced IL-12 p40 production in mouse macrophages when combined with lipopolysaccharide, a well-known inducer of IL-12 production. These findings may explain some of the known biological effects of berberine and suggests berberine as an immunotherapeutic compound for induction of IL-12, which is potentially applicable for tumors, infectious disease, and airway inflammation.