Antibacterial and laxative activities of strictinin isolated from Pu'er tea (Camellia sinensis)

Strictinin, the major phenolic compound in Pu'er teas produced from young leaves and buds of wild trees, was isolated to evaluate its antibacterial and laxative activities. The minimum inhibitory concentrations of strictinin against Propionibacterium acnes and Staphylococcus epidermidis were determined as 250 μM and 2000 μM, respectively, apparently higher than those of several antibiotics commonly used for bacterial infections. The additive and synergistic effects on the inhibitory activities of strictinin combined with other commercial antibiotics were observed in two bacteria tested in this study via the analysis of fractional inhibitory concentrations. Laxative activity was observed on defecation of the rats fed with strictinin. Further analysis showed that the laxative effect of strictinin was presumably caused by accelerating small intestinal transit, instead of enhancing gastric emptying, increasing food intake, or inducing diarrhea in the rats. Taken together with the antiviral activities demonstrated previously, it is suggested that strictinin is one of the active ingredients responsible for the antiviral, antibacterial, and laxative effects of wild Pu'er tea, and has the potential to be developed as a mild natural substitute for antibiotics and laxatives.

The Manufacturing Process of Kiwifruit Fruit Powder with High Dietary Fiber and Its Laxative Effect

Kiwifruit is rich in vitamins, minerals, dietary fiber and other functional components, and it has long been used as a functional food to treat intestinal ailments such as constipation. The current research made full use of the kiwifruit, the juice was prepared by microencapsulation, and the dietary fiber in kiwifruit pomace was modified by enzymatic hydrolysis and grinding, then, the two were mixed to obtain an ultra-micro kiwifruit powder (UKP). In addition, the laxative effect of the UKP was verified by a diphenoxylate induced constipated mice model. The results demonstrated that compared with the raw samples, the retention rate of vitamin C, lutein and catechin in UKP were 83.3%, 81.9% and 88.3%, respectively, thus effectively avoiding the loss of functional components during the processing of kiwifruit. Moreover, α-amylase, protease and the ball milling process effectively reduced the size of dietary fiber in kiwifruit pomace, and its water-holding capacity (WHC), oil-holding capacity (OHC) and swelling capacity (SWC) were enhanced by 1.26, 1.65 and 1.10 times, respectively. Furthermore, to analyze the laxative effect of the UKP, a constipation mice model was established by diphenoxylate treatment (5 mg·kg⁻¹, i.g.) for the last week, with or without UKP supplementation (2.4 g·kg⁻¹ B.W. per day) for 4 weeks. The results demonstrated that UKP significantly increased feces condition (fecal output and dejecta moisture content, gut transit (the intestinal propulsion rates) and substance P (SP) levels in portal vein plasma, and it decreased the whole gut transit time and mucinogen granules secreted by goblet cell in constipated mice.

Laxative effect of peanut sprout extract

Certain phenolic compounds are known to exhibit laxative properties. Seed sprouts, such as those of peanut, are known to promote de novo biosynthesis of phenolic compounds. This study was conducted to examine the potential laxative properties of 80% (v/v) ethanolic extract of peanut sprout (PSE), which contains a high concentration of phenolic compounds such as resveratrol. For this, SD rats were orally administered PSE while a control group was incubated with saline. Laxative effects were examined in both groups of rats. Constipation induced by loperamide in SD rats was improved by administration of PSE. Constipated rats showed increased intestinal movement of BaSO₄ upon administration of PSE compared to the control, and the groups administered 100 or 1,000 mg PSE/kg bw were not significantly different in transit time of the indicator. However, colon length was not statistically different among the experimental groups, although it was longer in the group incubated with 1 g PSE/kg bw compared to other groups. Further, there was no significant difference in stool number among the experimental groups. Taken together, these findings show that PSE has a laxative effect in a rat model of loperamide-induced constipation.

Regulation of gastrointestinal hormones during laxative activity of gallotannin-enriched extract isolated from Galla Rhois in loperamide-induced constipation of SD rats

Regulation of gastrointestinal hormones have been reported in animal models for constipation undergoing laxative therapy when administered herbal products. We undertook to investigate whether the laxative activity of gallotannin-enriched extracts isolated from Galla Rhois (GEGR) affects the regulation of gastrointestinal hormones, by examining the concentration of four hormones and the activation of their receptors in the loperamide (Lop)-induced constipation model. Stool parameters, including number, weight and water content, were significantly recovered in the Lop+GEGR treated group, relative to the Lop+vehicle treated group; however, food intake and water consumption were maintained at a constant level. Also, a similar recovery was detected for thickness of mucosa, muscle and flat luminal surface in the Lop+GEGR treated group. Furthermore, concentration of the four gastrointestinal hormones evaluated, namely, cholecystokinin (CCK), gastrin (GAS), somatostatin (SS) and motilin (MTL), were lower in the Lop+vehicle treated group than the No treated group, but were remarkably enhanced in the Lop+GEGR treated group. Moreover, the downstream signaling pathway of MTL and SS receptors were recovered after GEGR administration. Results of the present study therefore indicate that the laxative effects of GEGR treatment may be tightly related with the regulation of gastrointestinal hormones in the Lop-induced constipation model.

Citric Acid-Enriched Extract of Ripe Prunus mume (Siebold) Siebold & Zucc. Induces Laxative Effects by Regulating the Expression of Aquaporin 3 and Prostaglandin E2 in Rats with Loperamide-Induced Constipation

Previously, we demonstrated that extracts of the ripe fruit (rPM) and unripe fruit (uPM) of Prunus mume (Siebold) Siebold & Zucc. and citric acid have a laxative effect, which is at least partially mediated by the increase in fecal parameters as seen in the low-fiber diet-induced constipation model rats. This study aims at investigating the laxative effects of citric acid-enriched aqueous extracts of rPM, uPM, and its active compounds, such as citric acid and malic acid, on loperamide-induced constipation rat models. Animal studies were conducted with loperamide-induced constipation animal models. The results showed that rPM and citric acid, the major organic acid compounds, significantly improved stool parameters (number, weight, and water content of the stools) generated in loperamide-induced constipation rats, without adverse effects of diarrhea. The gastrointestinal (GI) motility was activated fully in the rPM- and citric acid-treated rats than in rats treaded with loperamide alone. In addition, when rPM and citric acid were added to RAW264.7 cells and used to treat loperamide-induced constipation model rats, the secretion of prostaglandin E2 (PGE2) increased significantly in cells and tissue. Furthermore, rPM and citric acid decreased the expression of the aquaporin 3 (AQP3) in the rat colons. Our results demonstrated that rPM and citric acid, the major organic acid compound in rPM, can effectively promote defecation frequency and regulate PGE2 secretion and AQP3 expression in the colon, providing scientific evidence to support the use of rPM as a therapeutic application.

Effect of Lactic Acid Bacteria-Fermented Mulberry Leaf Extract on the Improvement of Intestinal Function in Rats

This study examined the laxative effects of mulberry leaf extract (MLE) fermented by lactic acid bacteria (LAB), which contains high levels of polyphenolic and flavonoid compounds, against loperamide-induced constipation in rats. Sprague-Dawley rats were divided into a normal group (N) and three experimental groups; loperamide treated group (C), loperamide and LAB-fermented MLE 300 mg/kg treated group (MLEL), and loperamide and LAB-fermented MLE 600 mg/kg treated group (MLEH). After 33 d, fecal pellet amount, fecal weight, water content of fecal, gastrointestinal transit time and length, and serum lipid profiles were measured. Constipation was induced via subcutaneous injection of loperamide (2.0 mg/kg b.w., twice a day) for the final 5 d of the experiment. After loperamide administration, the LAB-fermented MLE groups showed a significantly increase in the fecal pellets number, wet weight, and water content in rats compared with the C group. Moreover, increases in the intestinal length and viable Lactobacillus numbers in the feces were observed in the LAB-fermented MLE groups. The intestinal transit time was shorter in the LAB-fermented MLE groups than in the C group. In addition, the LAB-fermented MLE groups showed a significant decrease in triglyceride and total cholesterol levels and an increase in HDL-cholesterol level. These results indicated that oral administration of LAB-fermented MLE shows laxative effect in loperamide-induced constipated rats.

Moringa oleifera Lam. Leaf improves constipation of rats induced by low-fiber-diet: A proteomics study

ETHNOPHARMACOLOGICAL RELEVANCE

The leaf of Moringa oleifera Lam., a medicinal and edible herb for thousands of years in Ayurveda, is used as Pancha (na) karma (purgative) during and after the body cleansing process, to treat constipation, reduce cholesterol and body weight.

AIM OF STUDY

The aim was to investigate the diarrhea effects and possible mechanism of M. oleifera leaves in constipation rats.

MATERIALS AND METHODS

The hot water extract of M. oleifera leaves (WEMOL) was prepared and analyzed using LC-20AT HPLC system. The constipated rat model was induced by feeding with low fiber diet for 21 days. After oral administration of WEMOL for 7 days, the excretion parameter analysis, gastro-intestinal propulsion, histological analysis by HE and Alcian blue staining, and gastrointestinal hormone in rat's digestive tract through ELISA were used to evaluate the laxative effect of WEMOL. Label-free quantitation (LFQ) with LC-MS/MS, bioinformatics and Western blot were used to discover and verify the signal pathways and key proteins of WEMOL related to diarrhea.

RESULTS

The contents of isoquercitrin and astragalin were 2.7 mg/g and 1.7 mg/g, respectively in WEMOL. The stool number, weight, and water content of constipation rats were significantly reduced, indicating model had been established successfully. WEMOL (1.25 and 2.5 g/kg) increased water content of feces and the levels of Gas, MTL, NPY in gastric antrum and VIP, SP in colon of constipation rats, improved the muscle layer thickness and mucin secretion of colon. The proteomics revealed a total of 1731 differential proteins and 9 signaling pathways, WEMOL increased the expression of Vamp2, Gnai3, and Prkacb.

CONCLUSIONS

The laxative mechanism of WEMOL maybe modulate the signaling pathways mediated by 5-HT and Ach receptors, related to gastrointestinal motility and intestinal fluid secretion. It can be considered as the scientific connotation of Pancha (na) karma of M. oleifera leaves in ayurveda.