Development of a psoriatic-like skin inflammation rat model using imiquimod as an inducing agent.

OBJECTIVE: The present investigation was undertaken to develop a psoriatic-like skin inflammation rat model using imiquimod (IMQ) as an inducing agent. MATERIALS AND METHODS: The hairs of the back dorsal portion of the Wistar rats were removed and 80, 100, and 120 mg of IMQ cream (5% w/w) for 10 consecutive days was applied to different groups of rats. Further, psoriasis area severity index was used for calculating the psoriatic score, which included scoring of erythema, scaling, and thickening. Various biochemical parameters, pro-inflammatory cytokines, vascular endothelial growth factor (VEGF), and histopathological examination were also performed. RESULTS: The results demonstrated signs of erythema, scaling, and thickening on group applied with 120 mg and 100 mg of IMQ along with ear thickening. Biochemical evaluation revealed a significant increase in the granulation tissue weight followed by significant decrease in the levels of collagen and hexosamine. The antioxidant parameters superoxide dismutase and catalase were found to decline, while nitric oxide and lipid peroxidation were significantly elevated in skin lesions, also supported by increased pro-inflammatory cytokines expression, i.e., interleukin (IL)-1 ß, IL-6, IL-17, tumor necrosis factor-α, and VEGF. Histopathological studies revealed a disturbed natural structure along with increased epidermal proliferation, abnormal differentiation with increased number of keratinocytes in the psoriatic skin tissue. CONCLUSION: From the overall study, we have successfully developed a psoriatic-like skin inflammation rat model for the first time on Wistar strain using IMQ as an inducing agent.

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-1ß 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.

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-1ß 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.

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-1ß 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.

Wound healing potential of Solanum xanthocarpum in streptozotocin-induced diabetic rats.

OBJECTIVES: The objective of the present study was to evaluate wound healing potential of Solanum xanthocarpum extract in streptozotocin-induced diabetic rats. METHODS: Alcoholic extract of the aerial parts (ESX) was subjected to phytochemical estimations and its standardization with chlorogenic acid using HPLC. ESX was then evaluated for wound healing potential in, streptozotocin-induced diabetic rats using excision and incision wound models on topical and oral treatment Various biochemical evaluations, such as collagen, hexosamine, hyaluronic acid, protein, DNA along with antioxidant parameters, proinflammatory cytokines, VEGF and histopathological examination were also evaluated. KEY FINDINGS: Extract of S. xanthocarpum depicted the presence of mainly alkaloids, polyphenols, steroids, while content of chlorogenic acid was found to be 8.44% w/w. The maximum effective nature of ESX in healing was observed at 10% gel (topical) and 200 mg/kg (orally) in diabetic rats, where highest healing power was observed when treated both orally and topically. Biochemical evaluations showed significant increase in the levels of collagen, hexosamine, hyaluronic acid, protein, DNA followed by significant decline in the levels of blood glucose, lipid peroxidation, nitric oxide and expression of proinflammatory cytokines, supported by histopathology. CONCLUSIONS: The potential healing effect in diabetic rats may be attributed to the presence of chlorogenic acid in combination with other phytoconstituents.

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

BACKGROUND: Roots of the plant Eriosema chinense Vogel (Fabaceae) is distributed mainly over the Eastern Himalayan region of India and China. The roots of the plant are used as a vegetable by the people of Northern Australia, China and North East India and are used traditionally by the tribal people of Meghalaya (India) for the treatment of diarrhoea. It has been reported to have significant antidiarrhoeal, cytotoxic and antimycobacterial activity. PURPOSE/OBJECTIVE: The present investigation was undertaken to isolate a lead molecule responsible for the observed antidiarrhoeal activity. METHODS: Eriosematin E, a prenylated flavanone, was isolated using column chromatography and was characterized by comparing its melting point and spectroscopic data (UV, IR, 1H NMR, 13C NMR, Mass Spectra) from literature. Eriosematin E (2.5, 5 and 10mg/kg p.o.) was then screened for normal faecal excretion rate and castor oil-induced diarrhoea models in rats. Further, it was examined for small intestinal transit, intestinal fluid accumulation and PGE2 induced enteropooling models in rats. Biochemical estimations and Na+ and K+ concentration in intestinal fluid were also determined along with colonic histopathological studies. RESULTS: The results illustrated a significant (P< 0.05) reduction in normal faecal output at 10mg/kg p.o. after 5th and 7thh of treatment and also showed maximum protection of 69.43% from diarrhoea in the castor oil-induced diarrhoea model. Significant results were also observed at the maximum effective dose of eriosematin E (10mg/kg p.o.) in inhibiting peristaltic index (small intestinal transit) and reducing intestinal fluid volume of castor oil induced and PGE2 induced enteropooling models. Further, eriosematin E restored all the alterations in biochemical parameters such as nitric oxide, protein, DNA, superoxide dismutase, catalase and lipid peroxidation. It also significantly recovered Na+ and K+ loss from body and confirmed its protective nature through the histopathological studies. CONCLUSION: The study corroborates the antidiarrhoeal potential of eriosematin E which may be attributed to its antisecretory and antioxidant potential.

Anti-psoriatic potential of Solanum xanthocarpum stem in Imiquimod-induced psoriatic mice model.

ETHNOPHARMACOLOGICAL RELEVANCE: The plant Solanum xanthocarpum Schrad. & Wendl. (Solanaceae) is one of the members of the dashamula (ten roots) in Ayurvedic system of medicine. The stem and fruits are used as an antipyretic, antiasthmatic and is prescribed in skin infections and for relief in burning sensation in the feet accompanied by vesicular eruptions. OBJECTIVE: To scientifically validate the anti-psoriatic potential of Solanum xanthocarpum stem in Imiquimod-induced psoriatic mice model. MATERIALS AND METHODS: Ethanolic stems extract of Solanum xanthocarpum (ESX) was first subjected to phytochemical screening and quantification of identified phytoconstituents, which was further standardized with the help of HPTLC using chlorogenic acid as a marker. The extract was then subjected to acute oral toxicity and skin irritability study for determining the safety profile of the extract. Imiquimod-induced psoriatic mouse model was then performed to check the efficacy of extract against psoriasis, where treatment was carried out for 15 days both topically (Gel at 2.5%, 5% and 10%) as well as orally (at 100, 200 and 400mg/kg p.o.) and their Psoriasis Area Severity Index (PASI) was calculated. The study also included determination of levels of TNF-α, IL-1ß, IL-6 and IL-17 in the animal tissues, which further included biochemical evaluations such as total collagen, hexosamine, hyaluronic acid DNA, protein antioxidant profiles such as lipid peroxidation, nitric oxide, superoxide dismutase and catalase along with histopathological studies of the tissues. RESULT: ESX showed the presence of mainly phenols, tannins, flavonoids, alkaloids and carbohydrates, while chlorogenic acid was reported to be 3.49% w/w. The Imiquimod-induced psoriatic mouse model, depicted a potent anti-psoriatic activity of the extract both topical (10%) and oral (200 and 400mg/kg p.o., as evident through PASI grading The effect was found to be more prominent in case of topically treated as compared to orally treated mice. The results also showed a significant inhibition in the expression of TNF-α, IL-1ß, IL-6 and IL-17 in treated animal tissues and also showed significant restoration of the altered biochemical parameters along with reduced hyperkeratinisation as observed through histopathology. CONCLUSION: The study scientifically justified the anti-psoriatic activity of the ESX, which may be attributed to inhibition in the expression of cytokines such as TNF-α, IL-1ß, IL-6 and IL-17. Further, the observed antioxidant, antimicrobial and cellular proliferative activities may act as a contributing factor in treatment of psoriasis, which may be attributed to the presence of chlorogenic acid along with other phytochemicals in combination.