Antidiarrhoeal activity of eriosematin E isolated from the roots of Eriosema chinense Vogel

Analysing the impact of eriosematin E from Eriosema chinense Vogel. against different diarrhoeagenic pathovars of Escherichia coli using in silico and in vitro approach

Since diarrhoea is reportedly the third largest cause of fatality among kids, therefore it is considered to be one of the major areas of concerns among developing nations. The main causative agents of diarrhoea include Escherichia coli, Vibrio cholera, and Shigella spp where E. coli shares the maximum contribution. The roots of the plant Eriosema chinense Vogel. (Fabaceae) are traditionally used by the native tribes of Meghalaya, India to treat diarrhoea. From previous reports, the plant and its marker eriosematin E have been reported to have antidiarrhoeal potential against pathogenic and nonpathogenic diarrhoea. Therefore, the objective of the current investigation was to use in silico studies to determine the efficacy of eriosematin E against different diarrhoeagenic strains of E. coli. Six different pathovars of E. coli i.e. enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enterohaemorrhagic E. coli (EHEC), enteroaggregative E. coli (EAEC), uropathogenic E. coli (UPEC) and enteroinvasive E. coli (EIEC) were subjected to docking simulation studies utilizing Glide module of Schrodinger Maestro 2018-1 MM Share Version. Based on the obtained binding energy and balance between H-bonding, hydrophobic, and salt bridge interactions eriosematin E was found to be most effective against EPEC followed by EAEC and ETEC, while UPEC and EHEC were moderately affected. The molecular dynamics studies suggested a higher affinity of eriosematin E towards heat-labile enterotoxin b-pentamer from ETEC. The in vitro antibacterial studies against the universal strain S. aureus 12981 and E. coli 10418 revealed the effectiveness of eriosematin E showing MIC values of ≥256 µg/mL.Communicated by Ramaswamy H. Sarma.

Protective role of ergothioneine isolated from Pleurotus ostreatus against dextran sulfate sodium-induced ulcerative colitis in rat model

The well-acknowledged sulfur-containing amino acid ergothioneine (EGT), which is usually perceived to be produced from fungi, cyanobacteria, and mushrooms, has been increasingly demonstrated as a diet-derived antioxidant with therapeutic potential. However, little is known regarding the therapeutic benefit against ulcerative colitis of EGT. Meanwhile, few studies have reported whether EGT could be produced by Pleurotus ostreatus, which is the second most cultivated edible mushroom worldwide, with ideal economic and ecological values and medicinal properties. In the current study, EGT was primarily extracted and isolated from P. ostreatus by water extraction and alcohol precipitation. Then, the Sephadex G-10 gel permeation chromatography and preparative high-performance liquid chromatography were employed in order to purify and collect EGT. Based on nuclear magnetic resonance spectrum characterization, the content of EGT extracted from P. ostreatus is 1.916 mg/g (the weight of EGT is the same as that of dry P. ostreatus). Finally, both the antioxidant activity in vitro and potential effects of EGT on dextran sulfate sodium-induced ulcerative colitis in rats were investigated. The results showed that the collected EGT exhibited strong antioxidant activity with a concentration-dependent manner in 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis (3-ethylbenzoline-6-sulphonic acid) assays. The oral administration of EGT can significantly alleviate colon length shortening and colonic pathological damage, mediated by downregulating the expression of pro-inflammatory factors and inhibiting TLR4/MyD88/NF-κB signaling pathway. Therefore, this study demonstrated that EGT from P. ostreatus would be an excellent dietary compound to ameliorate ulcerative colitis. PRACTICAL APPLICATION: In order to develop Pleurotus ostreatus as a functional food and related products for the prevention and treatment of ulcerative colitis, the separation and purification technology of ergothioneine (EGT) from P. ostreatus was studied, which not only provided a new and broader source for the acquisition and development of EGT, but also provided a basis for the development of EGT as a drug against UC.

The Genus Eriosema (Fabaceae): From the Ethnopharmacology to an Evidence-Based Phytotherapeutic Perspective?

The genus Eriosema (Fabaceae) includes approximately 150 species widely distributed across tropical and subtropical regions of the world (Africa, Neotropics, Asia and Australia). Throughout these regions, several species are used since centuries in different traditional medicinal systems, while others are used as food or food supplement. The present review attempts to critically summarize current information concerning the uses, phytochemistry and pharmacology of the Eriosema genus and to evaluate the therapeutic potential. The information published in English and French (up to September 2020) on ethnopharmacology or traditional uses, chemistry, pharmacology and toxicology of Eriosema genus was collected from electronic databases [SciFinder, PubMed, Google, Google Scholar, Scopus, Web of Science, Prelude Medicinal Plants—http://www.ethnopharmacologia.org/recherche-dans-prelude/?plant, The Plant List (http://www.theplantlist.org/), POWO (http://powo.science.kew.org/) and IUCN Red List Categories (https://www.iucnredlist.org/)], conference proceedings, books, M.Sc. and Ph.D. dissertations. The information retrieved on the ethnomedicinal indications of Eriosema genus allowed to list 25 species (∼16.6% of the genus). The majority of uses is recorded from Africa. Phytochemical analyses of 8 species led to the identification and/or isolation of 107 compounds, with flavonoids (69.2%), chromones (7.5%) and benzoic acid derivatives (3.7%) as the main chemical classes. Pharmacological investigations with crude extracts and isolated compounds showed a broad range of activities including aphrodisiac, estrogenic, anti-osteoporosis, hypolipidemic, anti-diabetic, anti-diarrheal, anti-microbial, anti-oxidant, anthelmintic, anti-cancer, and acetylcholinesterase inhibitory activities. Despite the low number of Eriosema species tested, there is convincing evidence in vitro and in vivo studies validating some traditional and ethnobotanical uses. However, the utility of several of the described uses has not yet been confirmed in pharmacological studies. Reviewed data could serve as a reference tool and preliminary information for advanced research on Eriosema species.

Diterpenoids from Leaves of Cultivated Plectranthus ornatus

Two new diterpenoid derivatives 7α,12β,17-triacetoxy-6β,19-dihydroxy-13β,16-spirocicloabiet-8-ene-11,14-dione ( 1: ) and 6β-acetoxy-3β,7α,12α-trihydroxy-13β,16-spirocicloabiet-8-ene-11,14-dione ( 2: ) along with 11 ( 3: - 13: ) miscellaneous compounds were isolated from the leaves of Plectranthus ornatus Codd. Their structures were elucidated by spectroscopic analysis and gauge independent atomic orbitals ¹³C NMR calculations. The isolated compounds were screened for their effects on intestinal motility using guinea-pig ileum and duodenum and by their cytotoxicity against 4 human cancer cell lines (HCT-116, SF-295, PC-3, and HL-60). Compounds 6: and 9: were moderately cytotoxic against HL-60, whereas 6: and 13: were more active on SF-295 and HCT-116.

Identifying the mechanism of eriosematin E from Eriosema chinense Vogel. for its antidiarrhoeal potential against Shigella flexneri-induced diarrhoea using in vitro, in vivo and in silico models

The main objective of the present investigation was to mechanistically evaluate the potency of the root extract (EEC), its bioactive chloroform fraction (CEC) and eriosematin E (ECM) isolated from Eriosema chinense against Shigella flexneri-induced sub-chronic model of infectious diarrhoea using in vitro, in vivo, and in silico methods. The in vitro antibacterial activity against pathogenic strain of S. flexneri demonstrated maximum effect of ECM followed by CEC and EEC in inhibiting growth of bacteria. Further, for in vivo evaluation, was carried out by inducing diarrhoea to the rats by administering oral suspension of S. flexneri to the animals, which was followed by treatment for a period of 6 days. EEC at 200, CEC at 100 and ECM at 10 mg/kg, p.o. showed promising effect, where EEC and ECM were found to be more effective showing maximum % protection on 6th day. Results also demonstrated a significant restoration of altered antioxidants, pro-inflammatory cytokines (IL-1β and TNF-α) expression, electrolyte balance, Na⁺/K⁺-ATPase activity and was also supported by histopathological examinations. Molecular docking study revealed that, eriosematin E inactivated the protease activity of SepA, a protein secreted by Shigella, which is responsible for disruption of epithelial barrier integrity. Thus, the overall observation confirmed the role of eriosematin E from E. chinense in treatment of Shigella flexneri-induced infectious diarrhoea.

Effects of Cortex Phellodendri extract on post-weaning piglets diarrhoea

The diarrhoea incidence rate is often high among weaning piglets. In light of the fact that Cortex phellodendri has long been used to treat diarrhoea in China, this study aimed to evaluate the effects of Cortex Phellodendri Extract (CPE) on diarrhoea in weaning piglets and the mechanism behind such effects. In the first trial, 36 diarrhoeal weaning piglets were randomly divided into three groups. The control group was injected with 20 mg oxytetracycline/kg BW, while the two treatment groups were orally administered with 10 mg and 20 mg CPE/kg BW respectively. In the second trial, 96 weaning piglets were randomly divided into two groups. The control group was fed basal diet, while 300 mg CPE/kg BW was added to the diet of the treatment group. The pathogenic bacteria were then isolated and identified from the diarrhoeal faecal samples. Cell adhesion and RT‐PCR tests were used to investigate the effect of CPE on the adhesion of pathogenic bacteria to IPEC‐J2 cells. 16S rDNA‐based high‐throughput sequencing was used to analyse faecal microflora. The results showed that CPE reduced the diarrhoea incidence rate (p < 0.05) and diarrhoea index (p < 0.05) compared to control group, and increased the richness and evenness of weaning piglets’ gut microbiota. Escherichia coli (E. coil) was identified as the causative organism. Cell adhesion and RT‐PCR tests suggested that CPE reduced the adhesion of E. coli to IPEC‐J2 cells (p < 0.05) and the expression of fae and faeG gene (p < 0.05) responsible for encoding E. coli fimbriae protein.

The antidiarrhoeal evaluation of Psidium guajava L. against enteropathogenic Escherichia coli induced infectious diarrhoea

ETHNOPHARMACOLOGICAL RELEVANCE

The plant Psidium guajava L. (Myrtaceae), commonly used as an edible fruit is traditionally used worldwide in treatment of various gastrointestinal problems including diarrhoea. The leaves of the plant have also been evaluated for antidiarrhoeal activity in various chemical induced diarrhoea models.

OBJECTIVE

The main objective of the present study was to evaluate the potency of P. guajava leaves and its major biomarker quercetin against enteropathogenic Escherichia coli (EPEC) induced infectious diarrhoea using preclinical and computational model.

MATERIAL AND METHODS

P. guajava alcoholic leaf extract (PGE) was initially standardized using HPLC taking quercetin as a biomarker and was then subjected to antidiarrhoeal evaluation on rats in an EPEC induced diarrhoea rat model. The study included assessment of various behavioral parameters, initially for 6 h and then for up to 24 h of induction which was followed by estimation of stool water content, density of EPEC in stools and blood parameters evaluation. The colonic and small intestinal tissues of the treated animals were subjected to various biochemical estimations, in vivo antioxidant evaluation, estimation of ion concentration, Na⁺/K⁺-ATPase activity, assessment of pro-inflammatory cytokines and histopathological studies. Further, the major biomarker off PGE, quercetin was subjected to molecular docking studies with Na⁺/K⁺-ATPase and EPEC.

RESULTS

The results demonstrated a significant antidiarrhoeal activity of quercetin (50 mg/kg), PGE at 200 and 400 mg/kg, p.o., where quercetin and PFGE at 200 mg/kg, p.o. were found to be more prominent, as confirmed through higher % protection, water content of stools and density of EPEC in stools. PGE and its biomarker quercetin also significantly recovered the WBC, Hb, platelets loss and also revealed a significant restoration of altered antioxidants level, pro-inflammatory cytokines (IL-1β and TNF-α) expression and had positive influence on Na⁺/K⁺-ATPase activity. The docking studies of quercetin with Na⁺/K⁺-ATPase showed favourable interactions and residues Glu 327, Ser 775, Asn 776, Glu 779 and Asp 804 of Na⁺/K⁺-ATPase were adequately similar to quercetin for donating ligands for binding, while quercetin was also found to terminate the linkage between mammalian cells and EPEC thus, preventing further infection from EPEC.

CONCLUSION

Inhibition in intestinal secretion, reduced nitric oxide production and inflammatory expression along with reactivation of Na⁺/K-ATPase activity could be attributed to the observed antidiarrhoeal potential of PGE against infectious diarrhoea, where quercetin was confirmed to be the main contributing factor.

Cortex Phellodendri extract's anti-diarrhea effect in mice related to its modification of gut microbiota

Cortex Phellodendri extract (CPE) has been used in China to treat diarrhea whereas the underlying mechanisms remain poorly understood. Given that dysbiosis of gut microbiota is a potential reason for diarrhea, and that oral CPE has a low absorption rate in intestine, we hypothesized that modification of gut microbiota is an important factor in CPE's anti-diarrhea effect. To test this hypothesis, we established a diarrhea model by challenging post-weaning mice with oral Enterotoxigenic-Escherichia coli (ETEC), and then the mice were treated with two doses of CPE (80 mg/kg bodyweight and 160 mg/kg bodyweight) or the vehicle control (phosphate buffered saline). Diarrhea indices, inflammatory factors, morphology of jejunum, short-chain fatty acids (SCFAs), and serum endocrine were determined. Modification of gut microbiota was analyzed using 16S rDNA high-throughput sequencing. The changes in functional profiles of gut microbiota were predicted using software PICRUSt. We then explored the association between CPE-responding bacteria and the symptoms indices with the spearman's rank correlation coefficient and significance test. Compared with diarrheal mice, CPE decreased Gut/Carcass ratio and water content of stool, increased goblet cell density and villus height/crypt depth of jejunum, as well as decreased inflammatory indices (Tumour Necrosis Factor-α, Myeloperoxidase and Interleukin-1α). CPE shifted the gut microbiota significantly by increasing alpha diversity (observed species, ace, Shannon, and Simpson) and restoring the gut microbiota. CPE increased Firmicutes and decreased Bacteroidetes. The reduced genus Prevotella, Acinetobacter, and Morganella were positively associated with the diarrhea indices, whereas increased genus Odoribacter, Rikenella, and Roseburia were negatively associated with the diarrhea indices. The abundance of carbohydrate metabolism-related gene and SCFAs-producing bacteria were increased, which was evidenced by increased butyric acid and total SCFAs concentration in the caecum. Consequently, endocrine peptides glucagon-like peptide-1, epidermal growth factor, and peptide tyrosine tyrosine in serum were elevated. CONCLUSIONS: CPE shows a shift function on the gut microbiota in alleviating the diarrhea of mice in a dose-dependent manner. In addition, the microbial metabolites SCFAs may mediate CPE's anti-diarrhea effect by enhancing endocrine secretion in mice.

Quercetin a major biomarker of Psidium guajava L. inhibits SepA protease activity of Shigella flexneri in treatment of infectious diarrhoea

The leaves of the plant Psidium guajava L. (Myrtaceae) has been traditionally used in treatment of various gastrointestinal disorders including diarrhoea and have also been reported for its potent antidiarrhoeal activity on various chemical induced diarrhoea models. The objective of our present study was to evaluate the potency of the leaf extract of the plant Psidium guajava (PGE) along with its major biomarker quercetin against Shigella flexneri-induced sub chronic model of infectious diarrhoea. PGE at 100, 200 and 400 mg/kg, p.o. and quercetin at 50 mg/kg, p.o. were administered to Shigella flexneri-induced diarrhoeal rats for five days and various behavioural parameters were evaluated on 1st, 3rd and 5th day of treatment. This was followed by assessment of stool water content, density of Shigella flexneri in stools and blood parameters examination. After treatment, colon and small intestine of rats was dissected and subjected to biochemical estimations, cytokine profiling, antioxidant evaluations, ion concentration determination, Na⁺/K⁺-ATPase activity and histopathology. Molecular docking studies on crystal structure of Secreted Extracellular Protein A (SepA) from Shigella flexneri with biomarker quercetin was also performed. PGE at 200 mg/kg followed by quercetin depicted maximum antidiarrhoeal potential, which was confirmed through diarrhoea score and % protection, while PGE at 400 mg/kg showed similar effect to PGE 200 mg/kg thus, the later may have ceiling effect. PGE and quercetin also significantly reduced the density of Shigella flexneri in stools, water content of stools and restored the alterations observed in blood parameters, antioxidant status and pro-inflammatory cytokines (IL-6 and TNF-α) expression. These parameters contributed in normalization of electrolyte balance, reactivation of Na⁺/K⁺-ATPase activity and repairing of epithelial tissue damage, confirmed through histopathology. Docking simulation studies revealed the role of quercetin in inactivating the protease activity of SepA, a protein secreted by Shigella, which disrupts epithelial barrier integrity during infection and also manages its signal production. Thus, the overall results confirmed the role of quercetin as a major biomarker for the observed antidiarrhoeal potential of P. guajava against Shigella flexneri induced infectious diarrhoea.

The potency of eriosematin E from Eriosema chinense Vogel. against enteropathogenic Escherichia coli induced diarrhoea using preclinical and molecular docking studies

The main objective of the present study was to evaluate the potential of eriosematin E (ECM) isolated from the roots of Eriosema chinense against enteropathogenic Escherichia coli (EPEC) induced diarrhoea. ECM isolated from the bioactive chloroform fraction of E. chinense was subjected to antidiarrhoeal evaluation on rats against diarrhoea, induced by the oral suspension of EPEC. The study included evaluation of behavioral parameters for 6 h and up to 24 h of induction, followed by estimation of water content, the density of EPEC in stools and evaluation of various blood parameters. Further, the colonic and small intestinal tissues were subjected to biochemical estimations, antioxidant evaluation, determination of ion concentration, Na⁺/K⁺ -ATPase activity, pro-inflammatory cytokines assessment and histopathology. Finally, the impact of ECM on Na⁺/K⁺-ATPase was studied through molecular docking studies. Significant antidiarrhoeal potential of ECM was demonstrated at 5 and 10 mg/kg, p.o., however, ECM at 10 mg/kg, p.o. was found to be more effective, as confirmed through higher % protection, density of EPEC in stools and water content of stools. ECM also significantly increased the level of WBC, Hb, platelets and revealed restoration of altered antioxidants, pro-inflammatory cytokines (IL-1β and TNF-α) status and also reactivated the suppressed Na⁺/K⁺-ATPase activity, which was also confirmed through docking studies showing H-bonding of hydroxyl group of ECM with amino acids Asp 190, Asn 167 and Glu 169 thus, maintaining proper electrolyte balance and also prevented epithelial tissue damage. The overall effect of ECM may be attributed to the decline in the elevated level of cytokines, inhibition in nitric oxide production and reactivation of Na⁺/K⁺-ATPase activity resulting in reduced intestinal secretion.

A Review on the Phytochemistry, Medicinal Properties and Pharmacological Activities of 15 Selected Myanmar Medicinal Plants

Medicinal plants are a reservoir of biologically active compounds with therapeutic properties that over time have been reported and used by diverse groups of people for treatment of various diseases. This review covers 15 selected medicinal plants distributed in Myanmar, including Dalbergia cultrata, Eriosema chinense, Erythrina suberosa, Millettia pendula, Sesbania grandiflora, Tadehagi triquetrum, Andrographis echioides, Barleria cristata, Justicia gendarussa, Premna integrifolia, Vitex trifolia, Acacia pennata, Cassia auriculata, Croton oblongifolius and Glycomis pentaphylla. Investigation of the phytochemical constituents, biological and pharmacological activities of the selected medicinal plants is reported. This study aims at providing a collection of publications on the species of selected medicinal plants in Myanmar along with a critical review of the literature data. As a country, Myanmar appears to be a source of traditional drugs that have not yet been scientifically investigated. This review will be support for further investigations on the pharmacological activity of medicinal plant species in Myanmar.

Antidiarrheal and protein conservative activities of Psidium guajava in diarrheal rats

OBJECTIVE

Psidium guajava occurs worldwide in tropical and subtropical areas. It has been used to treat inflammation, diabetes, fever, hypertension and ulcers. However, its antidiarrheal and protein conservative activities still need to be investigated.

METHODS

Fifty-four male rats were divided into normal and diarrheal rats. The normal rats were divided into 4 groups: control, low-dose P. guajava leaf extract (50 mg/kg), high-dose P. guajava leaf extract (100 mg/kg) and gallic acid. Treatments were administrated orally in 1 mL saline for a 1-month period. The diarrheal rats were divided into 5 groups: desmopressin (0.2 mg/kg) drug, low-dose P. guajava leaf extract (50 mg/kg), high-dose P. guajava leaf extract (100 mg/kg), gallic acid and an untreated control. Doses were given daily for a 1-month period while the untreated control received no treatment.

RESULTS

Diarrhea was responsible for an observed decline in kidney weight and serum sodium, potassium and chloride. Further, diarrhea was positively correlated with a significant increase in urine volume, and excretion of electrolytes, serum urea, creatinine and uric acid in the urine. In contrast, there was a proportional increase in the lipid peroxidation value in diarrhea and a significant decline was observed in serum superoxide dismutase, glutathione peroxidase and glutathione levels in diarrhea. Also, diarrhea inhibited blood proteins. The oral intake of P. guajava leaf extract by diarrheal rats restored all of these parameters to near normal levels. High-dose P. guajava leaf extract was more effective than the same compound at a low dose.

CONCLUSION

P. guajava leaf extract elicited antidiarrheal and protein conservative effects.

Linalyl acetate prevents olmesartan-induced intestinal hypermotility mediated by interference of the sympathetic inhibitory pathway in hypertensive rat

Olmesartan-associated enteropathy (OAE) is a life-threatening pathological condition, but its underlying mechanisms have not been elucidated. Although intestinal hypermotility is frequently accompanied by chronic diarrhea, there have been no studies of olmesartan-induced hypermotility. Intestinal motility should be well regulated by the enteric nervous system, but degeneration of enteric neurons has been reported in patients with chronic diarrheal diseases, such as irritable bowel syndrome, suggesting a connection between OAE and intestinal hypermotility. In this study, interference with this inhibitory pathway was analyzed in a model of olmesartan-induced intestinal hypermotility (OIH) in rats with nicotine-induced hypertension exposed to chronic immobilizing stress. The effects of the potent inhibitory neurotransmitters norepinephrine (NE) and sodium nitroprusside (SNP), which act via different pathways, were assessed ex vivo, with only NE-modulated frequency and amplitude of spontaneous contractions found to be elevated in OIH rat jejunum. Clinical symptoms frequent in OAE, including atrophy of the intestinal epithelium and weight loss, were observed in these rats. Interestingly, olmesartan significantly elevated heart rate while lowering blood pressure in OIH rats. These abnormal conditions were prevented by adding linalyl acetate (LA), while the blood pressure-lowering effects of olmesartan were maintained. These findings suggest that olmesartan induces intestinal hypermotility by interfering with the sympathetic inhibitory pathway, and reduces epithelial cell size or body weight in hypertensive rats. As LA prevented these effects, combination treatment with olmesartan plus LA may provide better antihypertensive efficacy without inducing OAE.