Prophylactic Pattern Scanning Laser Retinal Photocoagulation for Diabetic Retinopathy in Spontaneously Diabetic Torii Fatty Rats: Preliminary Experimental Results

Research Background and Purpose: The number of diabetic patients is rapidly increasing, making it crucial to find methods to prevent diabetic retinopathy (DR), a leading cause of blindness. We investigated the effects of prophylactic pattern scanning laser retinal photocoagulation on DR development in Spontaneously Diabetic Torii (SDT) fatty rats as a new prevention approach. Methods: Photocoagulation was applied to the right eyes of 8-week-old Spontaneously Diabetic Torii (SDT) fatty rats, with the left eyes serving as untreated controls. Electroretinography at 9 and 39 weeks of age and pathological examinations, including immunohistochemistry for vascular endothelial growth factor and glial fibrillary acidic protein at 24 and 40 weeks of age, were performed on both eyes. Results: There were no significant differences in amplitude and prolongation of the OP waves between the right and left eyes in SDT fatty rats at 39 weeks of age. Similarly, no significant differences in pathology and immunohistochemistry were observed between the right and left eyes in SDT fatty rats at 24 and 40 weeks of age. Conclusion: Prophylactic pattern scanning retinal laser photocoagulation did not affect the development of diabetic retinopathy in SDT fatty rats.

Mechanism of QHF-cisplatin against hepatocellular carcinoma in a mouse model

AIM: To study the effects of QHF-cisplatin on H22 hepatocellular carcinoma(HCC) and their mechanisms of action.METHODS: Sixty BALB/c mice were randomly divided into a model group(n = 48) and a normal control group(n = 12). An HCC xenograft tumor was created by injecting H22 cells directly into the liver parenchyma of the mice. The 48 BALB/c mice in the model group were randomly divided into four groups: QHF, DDP(cisplatin), QHF plus DDP, and model control. The inhibitory effects of these drugs on tumor growth were evaluated by calculating the rate of tumor growth inhibition. The mice were examined by observing their general condition, body weight and survival time. Changes in tumor tissue were observed under anoptical microscope. Aspartate aminotransferase(AST), alanine aminotransferase(ALT) and α-fetoprotein(AFP) levels in serum were measured. Hepatocyte growth factor(HGF), c-mesenchymal-epithelial transition(c-Met) factor, phosphorylated(p)-c-Met, p38, p-p38, extracellular signal-regulated kinase(ERK), p-ERK and vascular endothelial growth factor(VEGF) levels were evaluated in tumor and liver tissues using western blotting. RESULTS: Compared with the DDP group, a lower incidence of toxic reactions and a higher survival time were observed in the QHF plus DDP group. Tumor weight was significantly lower in the QHF, DDP and QHF plus DDP groups than in the model control group(0.24 ± 0.07, 0.18 ± 0.03 and 0.14 ± 0.01 g vs 0.38 ± 0.05 g, respectively), and the differences were statistically significant(P < 0.01). The rate of tumor growth inhibition in the QHF, DDP and QHF plus DDP groups was 38.7%, 52.6% and 63.5%, respectively. AST, ALT and AFP levels in serum were significantly lower in the QHF, DDP and QHF plus DDP groups compared to the model control group(P < 0.05). Similarly, HGF, p-c-Met, p-p38, p-ERK and VEGF levels in tumor tissue were significantly lower in the QHF, DDP and QHF plus DDP groups(P < 0.05).CONCLUSION: QHF and DDP have an antiangiogenic effect on H22 HCC in mice. QHF inhibits tumor growth via blocking the HGF/c-Met signaling pathway, inhibiting p38, ERK and VEGF signaling.

Preliminary pharmacological evaluation of Alocasia indica Schott tuber

To elucidate potential antioxidant, antidiarrheal, cytotoxic, and antibacterial activities of the ethanol extract of A/ocasia indica Schott tuber in different experimental models established in vitro and in vivo. METHODS： In vitro antioxidant activity was evaluated by 2, 2-diphenyl-l-picrylhydrazyl （DPPH） radical-scavenging assay. Phenolic content was estimated by using Folin-Ciocalteu＇s reagent while reducing ability was measured by ferric reducing power assay./n vivo antidiarrheal studies were carried out in mice, and the activity was evaluated in castor oil and magnesium sulfate- induced diarrhea. Disk diffusion assay was utilized to determine antibacterial activity against a number of pathogenic bacterial strains. Acute toxicity test was carried out to measure the safe doses for the extract. RESULTS： In DPPH radical-scavenging assay, the extract exhibited strong radical-scavenging activity with the 50% inhibitory concentration value of 42.66 IJg/mL. Total phenolic content was found to be 542.26 mg gallic acid equivalent per 100 g of dried tuber extract, whereas flavonoid content was found to be 4.30 mg quercetin equivalent/g of dried tuber extract. In reducing power assay, the extract showed strong reducing power in a concentration-dependent manner. The extract significantly （P 〈 0.01） enhanced the latent period and decreased defecation in both castor oil- and magnesium sulfate-induced diarrhea. The extract also lessened gastrointestinal motility in mice. Potential antibacterial activity was exhibited by the extract against all the tested bacterial strains in disk diffusion assay. The 50% lethal concentration against brine shrimp nauplii was 81.09 μg/mL. CONCLUSION： The results demonstrated that the ethanol extract of A. inc/ica has potential antioxidant, antidiarrheal, cytotoxic, and antibacterial activity.

Pharmacological evaluation of Musa seminifera Lour. fruit

OBJECTIVE： To study potential antioxidant, analgesic, antidiarrheal, and antibacterial activities of the ethanol extract of Musa seminifera Lour. fruit in different established in vivo and in vitro experimental models. METHODS： In vitro antioxidant activity was studied in 2,2-diphenyl-1-picrylhydrazyl （DPPH） radical-scavenging assay. Phenolic content was determined using Folin-Ciocalteu＇s reagent. Reducing ability was evaluated by ferric reducing power assay. Peripherally and centrally acting analgesic activity was studied in three different in vivo models, namely, acetic acid-induced writhing, hot-plate test, and tail-flick test in Swiss albino mice. In vivo antidiarrheal activity was evaluated in castor oil- and magnesium sulfate-induced diarrhea in mice. Gastrointestinal motility test was also carried out in mice. All studies in mice were undertaken at the doses of 250 and 500 mg/kg body weight. Antibacterial activity was assessed by disk diffusion assay against some Gram-positive and Gram-negative bacterial strains. Acute toxicity test was conducted to assess the safe doses of the extract. RESULTS： The extract showed 50% inhibitory concentration value of 12.65 μg/mL in DPPH radical- scavenging assay. Phenolic content was found to be 589.83 mg gallic acid equivalent per 100 g of dried fruits extract. Reducing power was in a concentration-dependent manner, and strongly comparable with the standard ascorbic acid. The extract demonstrated significant inhibition of writhing in acetic acid-induced writhing test at both dose levels （P〈0.01）. The extract also raised pain threshold in both hot-plate and tail-flick test in a dose-dependent manner, and the results were statistically significant （P〈0.01）. The extract significantly （P〈0.01） increased latent period, and decreased defecation in both castor oil- and magnesium sulfate-induced diarrhea. The extract also decreased gastrointestinal motility in mice. In disk diffusion assay, the extract showed potential antibacterial activity against all the tested bacterial strains. CONCLUSION： The results suggest that the ethanol extract of M. seminifera fruit has potential antioxidant, analgesic, antidiarrheal, and antibacterial activities.

Hepatoprotective and Antioxidant Effects of <i>Salvia officinalis</i>L. Hydroalcoholic Extract in Male Rats

The antioxidant effects of Salvia officinalis L. hydroalcoholic extract and also its hepatoprotective effects in male rats were evaluated. Salvia officinalis L. extract was administered intraperitoneally for 28 days. Serum levels of aspartate aminotransferase, alanine transferase and alkaline phosphates in rats coadministered with both isoniazid (INH) 50 mg/kg and Salvia officinalis L. extract at 250 mg/kg showed significant reduction when compared to INH group, but administration of Salvia officinalis L. extract 250 mg/kg alone and with INH has alleviated gamma-glutamyl transferase comparing to INH receiving rats. After treatment of rats with INH 50mg/kg, severe tissue necrosis, and inflammation of central vein in liver and lymphocyte proliferation were observed;in the experimental group receiving Salvia officinalis L. extract (250 mg/kg) mild dilution in central vein and sinusoids in liver were seen. In rats coadministered with Salvia officinalis L. extract 250 mg/kg and INH low sinusoids dilution was indicated. It seems that Salvia officinalis L. extract exhibited anti-oxidative and hepatoprotective effects.

Role of Sphingosine 1-Phosphate (S1P) Receptor 1 in Experimental Autoimmune Encephalomyelitis —I

Infiltration of myelin-specific helper T (Th) cells into the central nervous system (CNS) plays a key role in pathogenesis of experimental autoimmune encephalomyelitis (EAE). In this study, we investigated the involvement of sphingosine 1-phosphate (S1P)-S1P receptor 1 (S1P1) axis in lymphocytes for EAE development when C57BL/6 mice were immunized with myelin oliogodendrocyte glycoprotein (MOG). The expression of S1P1 mRNA and S1P responsiveness of lymphocytes in draining lymph nodes (DLN) were down-regulated markedly after MOG immunization until onset of EAE. Accompanying with reacquisition of down-regulated S1P1 transcript and S1P responsiveness in DLN lymphocytes, MOG-immunized mice developed EAE symptoms with significant infiltration of Th1 and Th17 cells into the CNS and a marked elevation of IFN-γ, T-bet, IL-17, and RORγt mRNA expressions. Prophylactic administration of an S1P1 functional antagonist, fingolimod hydrochloride (FTY720, 0.3 mg/kg, orally) significantly inhibited EAE development and almost completely prevented infiltration of Th1 and Th17 cells into the CNS with a marked reduction of IFN-γ, T-bet, IL-17, and RORγt mRNA expressions. Similar results were obtained by treatment with an S1P1-selective agonist, SEW2871 or an S1P lyase inhibitor, 2-acetyl-4-tetrahydroxybutylimidazole. Moreover, FTY720-phosphate and SEW2871 inhibited in vitro migration of Th1 and Th17 cells toward S1P but did not affect cytokine production or generation of Th1 or Th17 cells. These results suggest that reacquisition of S1P1 expression in DLN lymphocytes plays a major role in trafficking of myelin antigen-specific Th1/Th17 cells from DLN to the CNS in EAE and that prophylactic effect of FTY720 on EAE is predominantly caused by functional antagonism via lymphocytic S1P1.

Role of Sphingosine 1-Phosphate (S1P) Receptor 1 in Experimental Autoimmune Encephalomyelitis —II

Therapeutic administration of fingolimod hydrochloride (FTY720), the functional antagonist at sphingosine 1-phosphate (S1P) receptor 1 (S1P1) shows a marked improving effect on experimental autoimmune encephalomyelitis (EAE) induced by myelin oligodendrocyte glycoprotein (MOG) in C57BL/6 mice. However, this treatment showed an only partial inhibition of Th1/Th17 cell infiltration into the central nervous system (CNS), suggesting that down-regulation of lymphocytic S1P1 is insufficient to explain the therapeutic effect of FTY720 on EAE. On the other hand, the therapeutic administration of FTY720 reduced the mRNA expressions of IL-6, CCL2, and glial fibrillary acidic protein, an activation marker of astrocytes, in the CNS of EAE mice. In human astrocytic glyoma, U373MG cells, mRNA expression of S1P1 was higher as compared with those of the other S1P receptor subtypes and phosphorylation of Akt was induced by S1P, FTY720-phosphate (FTY720-P), or an S1P1-selective agonist, SEW2871. FTY720-P appeared to induce down-regulation of S1P1 in U373MG cells, implying a functional antagonism at S1P1 on astrocytes. S1P but not FTY720-P induced production of IL-6, IL-8, and CCL2 significantly and treatment with FTY720-P or SEW2871 inhibited production of these pro-inflammatory cytokines from U373MG cells stimulated with S1P. These results suggest that S1P-S1P1 axis induces production of pro-inflammatory cytokines by astrocytes. Consequently, it is highly probable that the therapeutic effects of FTY720 on EAE are caused by inhibiting not only egress of myelin-specific Th cells from the draining lymph nodes but also activation of astrocytes in the CNS.

Changes in protein tyrosine phosphatase activity in Spontaneously Diabetic Torii (SDT) rats

The Spontaneously Diabetic Torii (SDT) rat is a nonobese type 2 diabetic model, showing the overt hyperglycemia after about 16 weeks of age. In this study, we investigated the protein tyrosine phosphatase (PTPase) activities in insulin-sensitive tissues in SDT rats. PTPase activities in the liver, muscle, and fat were examined at 8 weeks (pre-diabetes), 16 weeks (onset-diabetes), and 24 weeks (diabetes). SDT rats showed glucose intolerance at 8 weeks and hyperglycemia after 16 weeks. The PTPase activities in fat increased at 8 weeks and the increase was sustained to 24 weeks. In the liver, PTPase activities increased only at 24 weeks. On the other hand, the PTPase activities in muscle did not change. The increase of PTPase activity in fat might be related to progression of glucose intolerance and diabetes in SDT rats.

Non-Obese Type 2 Diabetic Rat Models-GK Rat and SDT Rat

The number of diabetic patients has recently been increasing all over the world together with lifestyle changes including sedentary life and high-calorie diet intake, and as a result the increase in these suffering from diabetes mellitus has become a global issue. Diabetic animal models play a key role in bettering our understanding of the pathophysiology of diabetes and in developing new therapies for the disease. Diabetes is classified into two types, type 1 and type 2, and type 2 diabetes is chiefly caused by a depletion of insulin secretion in the pancreas and insulin resistance in peripheral tissues. The Goto-Kakizaki (GK) rat and the Spontaneously Diabetic Torii (SDT) rat are genetic non-obese type 2 diabetic models, and the both rats are considered to be suitable models for investigating the etiology of the depletion of insulin secretion and impaired glucose tolerance. In this review, we overviewed the outline of pathophysiological features in GK rats and SDT rats, including biological parameters and pharmacological responses.

Evaluation of the wound healing potential of isoquercetin-based cream on scald burn injury in rats

Background:The present study was designed to evaluate the potential of isoquercetin-based cream formulation on scald burn wound injury in rats.Methods:Four isoquercetin-based cream formulations viz.0.01,0.02,0.04,and 0.06%w/w were prepared.Cream base and standard anti-burn cream containing silver sulfadiazine were also used for comparison.Scald burn was given to rats by pouring water at 90℃on a shaved dorsal area of 20 mm2.Deep second-degree burn injury was produced which was evaluated for the next 21 days for the percentage of wound contraction and period of epithelialization.On day 21,the rats were sacrificed and histopathological slides were prepared using hematoxylin-eosin staining.Burned tissue was also screened for levels of oxidative stress using thiobarbituric acid reactive species(TBARS)and reduced glutathione(GSH)estimation.Results:There was a significant increase in the percentage of wound contraction and a significant decrease in the period of epithelialization in isoquercetin-based cream-treated groups as compared with the control group.However,most significant results were obtained with isoquercetin 0.06%w/w cream.Histological y,isoquercetin 0.06%w/w cream treatment resulted in almost complete re-epithelialization and re-structuring of the wound tissue.There was a significant rise in TBARS and a decrease in GSH levels in the burn injury group which was reversed to a major extent by the application of isoquercetin-based cream.Conclusions:The results indicate the wound healing potential of isoquercetin-based cream.Tissue biochemical studies indicate towards a possible role of free radical scavenging in the observed effects of isoquercetin in wound healing.