Comparative study of the laxative effects of konjac oligosaccharides and konjac glucomannan on loperamide-induced constipation in rats

Structure characteristics and fermentation properties of konjac oligosaccharides from konjac peel prepared by one-step fermentation with Bacillus Licheniformis BJ2022

Konjac peel is one of the main wastes in the processing of konjac. More effective green recycling solutions for konjac peel need to be developed. This study explored a green method for konjac oligosaccharide extraction from konjac peel, aiming to uncover the benefits of oligosaccharide preparation by Bacillus licheniformis (BJ2022) liquid-state fermentation. The extraction rate of fermented konjac oligosaccharides (FKO) by fermenting konjac peel in a 100 L fermentation tank reached 21.78 g/L, and the purity of the extracted oligosaccharides was 74.11 %. Pentasaccharides, hexasaccharides, and heptasaccharides were purified and separated from FKO. The oligosaccharides separated from FKO were composed of glucose and mannose connected by β-1,4-glycosidic bonds. The in vitro anaerobic fermentation experiments of gut microbiota and metabolomics analysis indicated that FKO had prebiotic activity in regulating gut microbiota and promoting the production of metabolites such as short-chain fatty acids. This study indicated that Bacillus licheniformis (BJ2022) one-step fermentation was a green and efficient konjac oligosaccharides production method.

Study on the Effect and Mechanism of Weichang'an Pill and Its Extract on Slow Transit Constipation

BACKGROUND

Weichang'an pill (WCA) possesses potential advantages in promoting gastrointestinal motility and treating constipation. Ethanol extract (EE) and aqueous extract (AE) of WCA were used to investigate its efficacy in treating slow transit constipation (STC) and the material basis for exerting this effect.

METHODS

The STC model was established in vivo by gavage of loperamide (Lop) in Sprague-Dawley rats, followed by gavage of WCA, EE, and AE. In vitro, norepinephrine (NE) was used to stimulate isolated ileal smooth muscle of rats to imitate the state of insufficient gastrointestinal motility during STC, and a model of excessive relaxation of isolated ileal smooth muscle was established. This model was used to observe and record the changes in contraction tension, amplitude, and frequency of ileal smooth muscle after treatment with WCA, EE, AE, and the active ingredients of WCA.

KEY RESULTS

In vivo, WCA, EE, and AE treatment increased fecal parameters, improved gastrointestinal transit time, and alleviated pathological damage to the colon in STC rats. Its mechanism might be closely related to c-kit/SCF, RhoA/ROCK/MYPT1/MLC signaling pathways. In vitro, WCA, EE, AE, and the active ingredients of WCA, including costunolide (Cos), dehydrocostus lactone (Deh), agarotetrol (Aga), muscone (Mus), gallic acid (GA), oleic acid (Oleic), linoleic acid (Lin), umbelliferone (Umb), synephrine (Syn), ferulic acid (FA), chlorogenic acid (ChA), betaine (Bet), and riboflavin (Rib), significantly inhibited the NE-induced excessive relaxation of ileal smooth muscles.

CONCLUSIONS

WCA, EE, and AE significantly improved constipation in STC rats. Moreover, the active ingredients in WCA, including Cos, Deh, Aga, Mus, GA, Oleic, Lin, Umb, Syn, FA, ChA, Bet, and Rib, might be the material basis for promoting intestinal motility.

Dietary fiber from burdock root ameliorates functional constipation in aging rats by regulating intestinal motility

Functional constipation is a common gastrointestinal health issue among the aging population. Dietary fiber supplementation is widely recognized as a first-line strategy for constipation. However, the effectiveness of dietary fiber in practical applications remains unsatisfactory, and dietary fibers from different sources are believed to possess varying physiological activities in alleviating constipation. Burdock root is a vegetable rich in dietary fiber. In this study, loperamide was used to induce functional constipation in aged rats. Doses of 3 mg/kg·bw·day and 1.5 mg/kg·bw·day of dietary fiber from burdock root were used to intervene in functional constipation in aged rats. Research indicated that dietary fiber from burdock root enhanced intestinal motility to ameliorate functional constipation in aging rats. This effect may involve several mechanisms, including repairing the intestinal barrier, regulating intestinal hormones, and providing anti-inflammation and antioxidation. Our findings provide a theoretical basis for the potential mechanism by which burdock root dietary fiber can ameliorate functional constipation. It is expected to serve as a natural functional food to combat functional constipation in the aging population.

The Particle Size of Wheat Bran Dietary Fiber Influences Its Improvement Effects on Constipation

Wheat bran dietary fiber (WBDF) is a potential functional additive to enrich products used for relieving constipation. The purpose of this study was to understand the effects of different particle size ranges (mean sizes of 84.14, 61.74, 37.39, and 22.33 μm) of WBDF on constipation. With the decrease in particle size, its morphology exhibited an increase in fiber fragmentation, larger pore sizes, and the formation of structural faults. The oil-holding capacity (OHC) and swelling capacity (SC) of WBDF were found to change with particle size, with the highest OHC observed at 37.39 μm and the greatest SC at 84.14 μm. Animal experiments demonstrated that the WBDF of smaller particle sizes significantly alleviated loperamide-induced constipation with an increased intestinal propulsion rate, decreased first melanin excretion time, and reduced gastric residual rate. Meanwhile, WBDF samples markedly increased serum MTL and serum AChE levels. Notably, compared with the constipation model (CMNC) group, the small intestinal propulsion rate in the MPS40 group increased by 41.21%, and the gastric residue rate significantly decreased by 19.69%. The improvement in constipation symptoms was most pronounced. Additionally, the abundance of Lactobacillus in the MPS40 group increased by 52.52%, while the relative abundance of Prevotella decreased by 83.55%, and the diversity of the gut microbiota was altered. These findings provide valuable insights into the potential commercial applications of WBDF in fiber-enriched functional foods to support intestinal health.

Fenchone Ameliorates Constipation-Predominant Irritable Bowel Syndrome via Modulation of SCF/c-Kit Pathway and Gut Microbiota

In this study we sought to elucidate the therapeutic effects of fenchone on constipation-predominant irritable bowel syndrome (IBS-C) and the underlying mechanisms. An IBS-C model was established in rats by administration of ice water by gavage for 14 days. Fenchone increased the reduced body weight, number of fecal pellets, fecal moisture, and intestinal transit rate, and decreased the enhanced visceral hypersensitivity in the rat model of IBS-C. In addition, fenchone increased the serum content of excitatory neurotransmitters and decreased the serum content of inhibitory neurotransmitters in the IBS-C rat model. Meanwhile, western blot and immunofluorescence experiments indicated that fenchone increased the expressions of SCF and c-Kit. Furthermore, compared with the IBS-C model group, fenchone increased the relative abundance of Lactobacillus, Blautia, Allobaculum, Subdoligranulum, and Ruminococcaceae_UCG-008, and reduced the relative abundance of Bacteroides, Enterococcus, Alistipes, and Escherichia-Shigella on the genus level. Overall, fenchone ameliorates IBS-C via modulation of the SCF/c-Kit pathway and gut microbiota, and could therefore serve as a novel drug candidate against IBS-C.

A novel purgative mechanism of multiflorin A involves changing intestinal glucose absorption and permeability

BACKGROUND

Multiflorin A (MA) is a potential active ingredient of traditional herbal laxative, Pruni semen, with unusual purgative activity and an unclear mechanism, and inhibiting intestinal glucose absorption is a promising mechanism of novel laxatives. However, this mechanism still lacks support and a description of basic research.

PURPOSE

This study aimed to determine the main contribution of MA to the purgative activity of Pruni semen and elucidate the effect intensity, characteristics, site, and mechanism of MA in mice, and determine the novel mechanism of traditional herbal laxatives from the perspective of intestinal glucose absorption.

METHODS

We induced diarrhoea in mice by administering Pruni semen and MA, and the defecation behaviour, glucose tolerance, and intestinal metabolism were analysed. The effects of MA and its metabolite on peristalsis of the intestinal smooth muscle were evaluated using an intestinal motility assay in vitro. Intestinal tight junction proteins, aquaporins, and glucose transporters expression were analysed using immunofluorescence; gut microbiota and faecal metabolites were analysed using 16S rRNA and liquid chromatography-mass spectrometry.

RESULTS

MA administration (20 mg/kg) induced watery diarrhoea in over half of the experimental mice. The activity of MA in lowering peak postprandial glucose levels was synchronous with purgative action, with the acetyl group being the active moiety. MA was metabolised primarily in the small intestine, where it decreased sodium-glucose cotransporter-1, occludin, and claudin1 expression, then inhibited glucose absorption, resulting in a hyperosmotic environment. MA also increased the aquaporin3 expression to promote water secretion. Unabsorbed glucose reshapes the gut microbiota and their metabolism in the large intestine and the increasing gas and organic acid promoted defecation. After recovery, the intestinal permeability and glucose absorption function returned, and the abundance of probiotics such as Bifidobacterium increased.

CONCLUSION

The purgative mechanism of MA involves inhibiting glucose absorption, altering permeability and water channels to promote water secretion in the small intestine, and regulating gut microbiota metabolism in the large intestine. This study is the first systematic experimental study on the purgative effect of MA. Our findings provide new insight into the study of novel purgative mechanisms.

Cymbopogon citratus (DC.) Stapf aqueous extract ameliorates loperamide-induced constipation in mice by promoting gastrointestinal motility and regulating the gut microbiota

Slow transit constipation (STC) is the most common type of functional constipation. Drugs with good effects and few side effects are urgently needed form the treatment of STC. Cymbopogon citratus (DC.) Stapf (CC) is an important medicinal and edible spice plant. The wide range of biological activities suggested that CC may have laxative effects, but thus far, it has not been reported. In this study, the loperamide-induced STC mouse model was used to evaluate the laxative effect of the aqueous extract of CC (CCAE), and the laxative mechanism was systematically explored from the perspectives of the enteric nervous system (ENS), neurotransmitter secretion, gastrointestinal motility factors, intestinal inflammation, gut barrier and gut microbiota. The results showed that CCAE not only decreased the serum vasoactive intestinal polypeptide (VIP), induced nitric oxide synthases (iNOS), and acetylcholinesterase (AchE) in STC mice but also increased the expression of gastrointestinal motility factors in colonic interstitial cells of Cajal (ICCs) and smooth muscle cells (SMCs), thereby significantly shortening the defecation time and improving the gastrointestinal transit rate. The significantly affected gastrointestinal motility factors included stem cell factor receptor (c-Kit), stem cell factor (SCF), anoctamin 1 (Ano1), ryanodine receptor 3 (RyR3), smooth muscle myosin light chain kinase (smMLCK) and Connexin 43 (Cx43). Meanwhile, CCAE could repair loperamide-induced intestinal inflammation and intestinal barrier damage by reducing the expression of the pro-inflammatory factor IL-1β and increasing the expression of the anti-inflammatory factor IL-10, chemical barrier (Muc-2) and mechanical barrier (Cldn4, Cldn12, Occludin, ZO-1, and ZO-2). Interestingly, CCAE could also partially restore loperamide-induced gut microbial dysbiosis in various aspects, such as microbial diversity, community structure and species composition. Importantly, we established a complex but clear network between gut microbiota and host parameters. Muribaculaceae, Lachnospiraceae and UCG-010 showed the most interesting associations with the laxative phenotypes; several other specific taxa showed significant associations with serum neurotransmitters, gastrointestinal motility factors, intestinal inflammation, and the gut barrier. These findings suggested that CCAE might promote intestinal motility by modulating the ENS-ICCs-SMCs network, intestinal inflammation, intestinal barrier and gut microbiota. CC may be an effective and safe therapeutic choice for STC.

Evaluation of the effect of prebiotic sesame candies on loperamide-induced constipation in mice

Constipation is one of the most common gastrointestinal tract symptoms. In this study, prebiotic sesame sugar (PSC) was prepared from isomalto-oligosaccharide, konjac glucomannan and sesame, and the relieving effect of PSC on constipation induced by loperamide was explored. The results showed that PSC treatment profoundly improved the defecation function and boosted intestinal motility. Moreover, PSC repaired gastrointestinal tissue injury and inflammation induced by constipation, which confirmed the effectiveness of PSC intervention in the treatment of constipation. The mechanism of PSC improving constipation might be that PSC improved the imbalance of gastrointestinal neurotransmitters and increased the content of short-chain fatty acids in feces. In conclusion, PSC dietotherapy could effectively alleviate the symptoms and lay a theoretical foundation for the development of an anti-constipation diet.

Comparative effects of different enzymatic hydrolysates of konjac glucomannan on gut flora and constipation rats

This study aimed to compare the effects of different hydrolysates (named GKOS and MKOS) on constipated rats, which were degraded to obtain from konjac glucomannan by β-glucanase and β-mannanase, respectively....