Correction: Shawky et al. The Biological Impacts of Sitagliptin on the Pancreas of a Rat Model of Type 2 Diabetes Mellitus: Drug Interactions with Metformin. Biology 2020, 9, 6.

In the original publication [...].

Lactobacillus rhamnosus GG and Tannic Acid Synergistically Promote the Gut Barrier Integrity in a Rat Model of Experimental Diarrhea via Selective Immunomodulatory Cytokine Targeting.

SCOPE: Diarrhea is a common health issue that contributes to a significant annual death rate among children and the elderly worldwide. The anti-diarrheal activity of Lactobacillus rhamnosus GG (LGG) and tannic acid (TA), alone or combined, is examined, in addition to their effect on intestinal barrier integrity. METHODS AND RESULTS: Fifty-six adult male Wistar rats are randomly assigned into seven groups: control, LGG alone, TA alone, diarrhea model, diarrhea+LGG, diarrhea+TA, and diarrhea+LGG+TA-treated groups. Diarrhea is induced by high-lactose diet (HLD) consumption. LGG (1x109 CFU/rat) and TA (100 mg Kg-1 d-1) were given orally 4 days after HLD feeding and continued for 10 days. Ileum specimens are processed for biochemical analysis of the local intestinal cytokines, polymerase chain reaction (PCR), and histological study. Also, immunohistochemistry-based identification of Proliferating Cell Nuclear Antigen (PCNA) and zonula occludens 1 (ZO-1) is performed. Compared to the diarrhea model group, both treatments maintain the intestinal mucosal structure and proliferative activity and preserve ZO-1 expression, with the combination group showing the maximal effect. However, LGG-treated diarrheic rats show a remarkable decrease in the intestinal tissue concentrations of tumor necrosis factor-alpha (TNF-α) and nuclear factor Kappa beta (NF-κB); meanwhile, TA treatment leads to a selective decrease of interferon-gamma (INF-γ) and transforming growth factor-beta (TGF-ß1). CONCLUSION: Individual LGG and TA treatments significantly alleviate diarrhea, probably through a selective immunomodulatory cytokine-dependent mechanism, while the combination of both synergistically maintains the intestinal mucosa by keeping the intestinal epithelial barrier function and regenerative capability.

The potential liver injury induced by metronidazole-provoked disturbance of gut microbiota: modulatory effect of turmeric supplementation.

It has been reported that the gut-liver axis and intestinal microbiome contribute crucially to different liver diseases. So, targeting this hepato-intestinal connection may provide a novel treatment modality for hepatic disorders such as drug-induced liver injury (DILI). The present study thought to investigate the protective effect of turmeric (TUR) on metronidazole (MNZ)-induced liver damage and the possible association of the gut-liver axis and gut microbiota as a suggested underlying mechanism. In the first experiment, a MNZ-induced liver injury rat model was reproduced after 130 mg/kg oral MNZ administration for 30 days. Meanwhile, the treatment group was orally treated with 100 mg/kg turmeric daily. In the second experiment, fecal microbiome transplantation (FMT) was conducted, in which the fecal microbiome of each group in the first experiment was transplanted to a healthy corresponding group in the second experiment. The liver enzymes (aminotransferase (ALT) and aspartate aminotransferase (AST)) and histopathological examination were estimated to assess liver function. Inflammatory cytokines and oxidative markers were evaluated in the liver tissues. Histological analysis, intestinal barrier markers, and expression of tight junction proteins were measured for assessment of the intestinal injury. Changes in the gut microbial community and possible hepatic bacterial transmission were analyzed using 16S rRNA sequencing. MNZ induced intestinal and liver injuries which were significantly improved by turmeric. Increased firmicutes/bacteroidetes ratio and bacterial transmission due to gut barrier disruption were suggested. Moreover, TUR has maintained the gut microbial community by rebalancing and restoring bacterial proportions and abundance, thereby repairing the gut mucosal barrier and suppressing bacterial translocation. TUR protected against MNZ-induced gut barrier disruption. Reshaping of the intestinal bacterial composition and prohibition of the hepatic microbial translocation were suggested turmeric effects, potentially mitigating MNZ-related liver toxicity.

Targeting NF-κB/COX-2 signaling by soyasaponin I alleviates diclofenac-induced gastric ulceration in male albino rats.

Gastric ulceration is a prevalent worldwide clinical presentation due to altered gastric defense mechanisms. Nonsteroidal anti-inflammatory drugs are one of the common causes of gastric ulcers mediated by the release of inflammatory mediators. The study aimed to investigate the potential protective effect of soyasaponin I (soya) against diclofenac (DIC)-induced gastric ulcer in rats and to highlight the underlying mechanisms. The experiment was conducted on 40 male Wistar albino rats, equally distributed into five groups: control, DIC-induced ulcer (9 mg/kg/d, orally, twice daily for 3 days), ulcer/soya-, ulcer/ranitidine-, and ulcer/soya/selective nuclear factor kappa B inhibitor (JSH-23)-treated groups. The doses of soya, ranitidine, and JSH were 20, 25, and 5 mg/kg/d, respectively, given orally. Gastric specimens were prepared for gene and histological study and for biochemical analysis of gastric prostaglandin E2 (PGE2), oxidative markers, and inflammatory cytokines. The gastric samples were formalin-fixed, paraffin-embedded, and subjected to hematoxylin and eosin (H&E), PAS staining, and immunohistochemical assay for identification of nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2), and proliferation marker (Ki67) expressions. The findings revealed decreased gastric PGE2 and altered inflammatory and oxidative markers in the ulcer model group. The H&E staining showed mucosal injury characterized by mucosal surface defects and inflammatory cell infiltrations. The polymerase chain reaction (PCR) and immunohistochemistry demonstrated an upregulation of NF-κB and COX-2 expression at gene/protein levels; meanwhile, Ki67 downregulation. The soya-treated group showed maintained biochemical, histological, and PCR findings comparable to the ranitidine-treated group. The JSH-23-treated group still showed partial gastric protection with biochemical and immunohistochemical changes. Soyasaponin I ameliorated DIC-induced gastric ulcers by targeting the COX-2 activity through modulation of NF-κB signaling.

Triclosan treatment to pregnant albino rats affects offspring numbers and the liver of both the pregnant rats and their offspring, and these effects are ameliorated by co-treatment with bee honey.

We have assessed the effects of the broad-spectrum bactericide triclosan on the liver of pregnant albino rats and their offspring, and evaluated the protective potential of bee honey, which has radical-scavenging properties. The study involved treatment of 72 pregnant rats followed by examination of the pregnant rats and their offspring. The pregnant rats were divided equally into six groups (I-VI), each of which was subdivided equally into two Subgroups (A and B). Rats in the A subgroups were gavaged with a daily dose of 1.26 ml distilled water (IA), 1 ml corn oil (IIA), 1.68 ml aqueous solution of Clover Blossom honey (IIIA), 0.3 mg triclosan (IVA), 13 mg triclosan (VA), or 1.68 ml aqueous solution of honey with 13 mg triclosan (VIA), throughout pregnancy. Rats in the B subgroups received the same treatments throughout pregnancy and for 14 days after delivery. At the end of the experiments, the offspring's numbers were recorded and blood samples were taken from the pregnant rats for analysis. The livers of the studied groups were subjected for; histological study, morphometric analysis, and biochemical estimation of markers of oxidative stress. The results showed that the acceptable daily intake of triclosan did not induce significant pathological changes in the liver while high dose of triclosan induced pathological changes in the livers and reduced the numbers of offspring. Co-administration of honey with triclosan ameliorated most pathological change. Therefore, decrease the exposure of the pregnant women to triclosan is encouraged or co-supplementation with bee honey if exposure could not be avoided.

The Biological Impacts of Sitagliptin on the Pancreas of a Rat Model of Type 2 Diabetes Mellitus: Drug Interactions with Metformin.

Sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, is a beneficial class of antidiabetic drugs. However, a major debate about the risk of developing pancreatitis is still existing. The aim of the work was to study the histological and immunohistochemical effects of sitagliptin on both endocrine and exocrine pancreases in a rat model of type 2 diabetes mellitus and to correlate these effects with the biochemical findings. Moreover, a possible synergistic effect of sitagliptin, in combination with metformin, was also evaluated. Fifty adult male rats were used and assigned into five equal groups. Group 1 served as control. Group 2 comprised of untreated diabetic rats. Group 3 diabetic rats received sitagliptin. Group 4 diabetic rats received metformin. Group 5 diabetic rats received both combined. Treatments were given for 4 weeks after the induction of diabetes. Blood samples were collected for biochemical assay before the sacrification of rats. Pancreases were removed, weighed, and were processed for histological and immunohistochemical examination. In the untreated diabetic group, the islets appeared shrunken with disturbed architecture and abnormal immunohistochemical reactions for insulin, caspase-3, and inducible nitric oxide synthase (iNOS). The biochemical findings were also disturbed. Morphometrically, there was a significant decrease in the islet size and islet number. Treatment with sitagliptin, metformin, and their combination showed an improvement, with the best response in the combined approach. No evidence of pancreatic injury was identified in the sitagliptin-treated groups. In conclusion, sitagliptin had a cytoprotective effect on beta-cell damage. Furthermore, the data didn't indicate any detrimental effects of sitagliptin on the exocrine pancreas.

Stem cells and metformin synergistically promote healing in experimentally induced cutaneous wound injury in diabetic rats.

INTRODUCTION: Diabetes mellitus (DM) is a serious, chronic metabolic disorder commonly complicated by diabetic foot ulcers with delayed healing. Metformin was found to have a wound healing effect through several mechanisms. The current study investigated the effect of both bone marrow-derived mesenchymal stem cells (BM-MSCs) and metformin, considered alone or combined, on the healing of an experimentally induced cutaneous wound injury in streptozotocin-induced diabetic rats. MATERIAL AND METHODS: Forty adult male albino rats were used. Diabetes was induced by single intravenous (IV) injection of streptozotocin (STZ). Next, two circular full thickness skin wounds were created on the back of the animals, then randomly assigned into 4 groups, ten rats each. BM-MSCs were isolated from albino rats, 8 weeks of age and labeled by PKH26 before intradermal injection into rats of Group III and IV. Groups I (diabetic positive control), II (metformin-treated, 250 mg/kg/d), III (treated with 2×106 BM-MSCs), and IV (wounded rats treated both with metformin and BM-MSCs cells). Healing was assessed 3, 7, 14, and 21 days post wound induction through frequent measuring of wound diameters. Skin biopsies were obtained at the end of the experiment. RESULTS: Gross evaluation of the physical healing of the wounds was done. Skin biopsies from the wound areas were processed for hematoxylin and eosin (H&E), Masson's trichrome staining and immunohistochemical staining for CD31. The results showed better wound healing in the combined therapy group (IV) as compared to monotherapy groups. CONCLUSIONS: Although both metformin and BM-MSCs were effective in the healing of experimentally induced skin wounds in diabetic rats, the combination of both agents appears to be a better synergistic option for the treatment of diabetic wound injuries.