Neuroprotective effect of Hibiscus rosa sinensis in an oxidative stress model of cerebral post-ischemic reperfusion injury in rats

Context: The ischemic brain lesions induced in rats by temporary occlusion of the bilateral common carotid arteries and restoration of blood flow to an ischemic brain region is associated with generation of reactive oxygen species with consequent reperfusion injury.

Objective: The present study investigated the neuroprotective potential of Hibiscus rosa sinensis L. (Malvaceae) in a bilateral common carotid artery (BCCA) occlusion model of global cerebral ischemic reperfusion.

Materials and methods: The animals underwent 30?min BCCA occlusion and 45?min reperfusion. The methanol extract of H. sinensis (100, 200, 300?mg/kg/day for 6 days, p.o.) was administered 30?min before induction of BCCA occlusion.

Results: The bilateral common carotid artery occlusion resulted in increase in lipid peroxidation, and reduction in superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GSH) activity. The extract attenuated the ischemic reperfusion-induced increase in lipid peroxidation and fall in SOD, CAT, and GSH levels. The cerebral hypoperfusion caused a propensity towards anxiety and was accompanied by deficits of learning and memory. The extract ameliorated anxiety and there was improvement of learning and memory.

Discussion: The administration of H. sinensis prevented the oxidative stress and the biochemical changes associated with cerebral ischemic reperfusion injury. The mechanism of such protection of H. sinensis may be due to cerebral adaptation, through augmentation of cellular antioxidants such as GSH, SOD and CAT. The results suggest the protective role of H. sinensis in ischemic reperfusion injury.

Conclusion: This study indicates the beneficial role of H. sinensis in cerebrovascular insufficiency states and dementia.     

Cognitive enhancing and antioxidant activity of ethyl acetate soluble fraction of the methanol extract of Hibiscus rosa sinensis in scopolamine-induced amnesia

Objective:

The objective of the present study was to evaluate the cognitive enhancing and antioxidant activity of Hibiscus rosa sinensis.

Materials and Methods:

The learning and memory was impaired by administration of scopolamine (1 mg/kg, i.p.) in mice which is associated with altered brain oxidative status. The object recognition test (ORT) and passive avoidance test (PAT) were used to assess cognitive enhancing activity. Animals were treated with an ethyl acetate soluble fraction of the methanol extract of H. sinensis (25, 50 and 100 mg/kg, p.o).

Results:

The ethyl acetate soluble fraction of the methanol extract of H. sinensis (EASF) attenuated amnesia induced by scopolamine and aging. The discrimination index (DI) was significantly decreased in the aged and scopolamine group in ORT. Pretreatment with EASF significantly increased the DI. In PAT, scopolamine-treated mice exhibited significantly shorter step-down latencies (SDL). EASF treatment showed a significant increase in SDL in young, aged as well as in scopolamine-treated animals. The biochemical analysis of brain revealed that scopolamine treatment increased lipid peroxidation and decreased levels of superoxide dismutase (SOD) and glutathione reductase (GSH). Administration of extract significantly reduced LPO and reversed the decrease in brain SOD and GSH levels. The administration of H. sinensis improved memory in amnesic mice and prevented the oxidative stress associated with scopolamine. The mechanism of such protection of H. sinensis may be due to augmentation of cellular antioxidants.

Conclusion:

The results of the present study suggested that H. sinensis had a protective role against age and scopolamine-induced amnesia, indicating its utility in management of cognitive disorders.     

Evaluation of burn wound healing activity of novel fusidic acid loaded microemulsion based gel in male Wistar albino rats

The objective of the present research was to examine the possible usage of microemulsion based gel for fusidic acid (FA) dermal application as burn wound treatment. During the preparation of microemulsion, ethyl oleate as oil phase, tween 80 as a surfactant, ethanol as co-surfactant, water as aqueous phase were used. The prepared microemulsions were evaluated for clarity, pH, viscosity and FA content. Moreover, stability, sterility, antibacterial activity, in vitro release of the formulations were also evaluated. The results showed that the FA loaded microemulsion and microemulsion based gel formation and characteristics were related to many parameters of the components. The performed optimized microemulsion-based gel showed good stability over a period of 3 months. The antibacterial activity of microemulsion-based gel was found to be comparable with marketed cream. RAW 264.7 macrophages were used to determine cell viability (MTT assay) and nitric oxide production. MBG and FA-MBG significantly inhibit the production of the inflammatory mediator NO in LPS-stimulated RAW 264.7 cells in a concentration-dependent manner. The wound healing property was evaluated by histopathological examination and by measuring the wound contraction. The % of wound area in rats treated with FA (2%) loaded microemulsion based gel ranged from 69.30% to 41.39% in the period from 3 to 10 days. In conclusion, FA loaded microemulsion based gel could be offered as encouraging strategy as dermal systems for the burn wound treatment.     

Protection of gastric mucosal damage by Coriandrum sativum L. pretreatment in Wistar albino rats

The effect of Coriander pretreatment on gastric mucosal injuries caused by NaCl, NaOH, ethanol, indomethacin and pylorus ligation accumulated gastric acid secretions was investigated in rats. Pretreatment at oral doses of 250 and 500mg/kg, body weight was found to provide a dose-dependent protection against the (i) ulcerogenic effects of different necrotizing agents; (ii) ethanol-induced histopathological lesions; (iii) pylorus ligated accumulation of gastric acid secretions and ethanol related decrease of Nonprotein Sulfhydryl groups (NP-SH). Results obtained on the study of gastric mucus and indomethacin-induced ulcers demonstrated that the gastro protective activity of Coriander might not be mediated by gastric mucus and/or endogenous stimulation of prostaglandins. The protective effect against ethanol-induced damage of the gastric tissue might be related to the free-radical scavenging property of different antioxidant constituents (linanool, flavonoids, coumarins, catechins, terpenes and polyphenolic compounds) present in Coriander. The inhibition of ulcers might be due to the formation of a protective layer of either one or more than one of these compounds by hydrophobic interactions.     

Camellia sinensis (green tea) extract attenuate acrylamide induced testicular damage in albino rats

Acrylamide is a proved toxin for testicular function, found in food when heated for long period of time. Green tea (Camellia sinensis) is a potent antioxidant; the aim of this study was to investigate the protective effect of green tea extract against the toxic effects of acrylamide in rat testes. Methods: acrylamide was administered orally to rats in different doses and also the extract of green tea was administered orally to different groups of animals in combination with the acrylamide. The weight of animals, testosterone hormone level and histopathological effect upon testicles were evaluated. Results: Testosterone hormone level in serum, and histopathological findings were significantly improved with the co‐administration of green tea extract with the acrylamide. Green tea extract reversed all the toxic effects of acrylamide even in high dose for long period (90 days). Conclusion: Green tea extract is a potent antioxidant antidote for the acrylamide toxic effects upon testicular function. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1155–1161, 2014.     

Toxicological effects of cadmium during pregnancy in Wistar albino rats

Cadmium is a heavy metal and widespread environmental toxicant. This study investigated the effects of prenatal Cd exposure on fetal growth and limb development in rats. Pregnant rats were given 0, 4 or 8 mg/kg/day (equivalent to ≈ 0, 30 or 60 ppm) of cadmium as CdSO₄ in their drinking water from conception to gestation day 20. Cd significantly (p<0.001) and dose-dependently inhibited maternal weight gain and caused abortion of pregnancy. In addition, Cd significantly (p<0.001) decreased fetal body weight, forelimb and hindlimb bone lengths, compared to controls. These effects were sex-dependent, greater in the female offspring. Furthermore, there were reductions in the weights, and alterations in the histology of maternal placenta, ovary and liver of Cd-exposed rats. The results indicate that cadmium will cause abortion of pregnancy and sex-dependent impairment of fetal growth and limb development, which may be consequent upon alterations in ovarian and placental functions.     

Dose-dependent serum biochemical alterations in Wistar albino rats after Palamneus gravimanus (Indian black scorpion) envenomation

Palamneus gravimanus envenomated rats showed dose-dependent alterations in serum biochemical parameters. Sub lethal doses of 100, 200, and 400 microg/kg of P. gravimanus venom were injected intramuscularly into rats. Blood samples were collected by heart puncture before and 4 h after crude venom administration. Serum was analyzed for glucose, blood urea nitrogen (BUN), uric acid, total protein, cholesterol, sodium, potassium, inorganic phosphorus, alkaline phosphatase, aspartate aminotransferase (AST-SGOT), alanine amino-transferase (ALT-SGPT), lactate dehydrogenase (LDH), and creatinine phosphokinase (CPK). Statistically significant increases in serum levels of glucose, creatinine, AST, ALT, BUN, CPK, and LDH and significant decreases in serum levels of total protein, uric acid, cholesterol, calcium, and potassium 4 h after venom administration could be due to the toxic action of P. gravimanus venom on certain organs in rats.     

Effect of Hibiscus rosa sinensis extract on hyperproliferation and oxidative damage caused by benzoyl peroxide and ultraviolet radiations in mouse skin

The present study was conducted to investigate the ameliorative potential of Hibiscus rosa sinensis extract in mice skin. Combination of a single topical application of benzoyl peroxide (20 mg/0.2 ml/animal) followed by ultraviolet radiations (0.420 J/m2/s) was used to induce hyperproliferation and oxidative stress. Single benzoyl peroxide application prior to ultraviolet B radiations exposure caused significant depletion in the detoxification and antioxidant enzymes, while malondialdehyde formation, hydrogen peroxide content, ornithine decarboxylase activity and DNA synthesis were raised significantly. However, pretreatment of H. rosa sinensis extract (3.5 mg and 7 mg/ kg b.wt.) partly restored the levels of cellular protective enzymes (P<0.05). Besides, malondialdehyde formation and hydrogen peroxide content (P<0.05) were statistically significantly reduced at both doses. The ornithine decarboxylase activity and thymidine incorporation in DNA were also reduced dose dependently (P<0.05) by the plant extract. Therefore, we propose that H. rosa sinensis extract exerts a protective effect against the tumour promotion stage of cancer development.     

Effect of papaya (Carica papaya linn) on pregnancy and estrous cycle in albino rats of Wistar strain

The antifertility effects of Carica papaya were investigated by feeding adult cycling and pregnant rats with different components of its fruits. No attempt was made to force-feed the animals. The results indicate that unripe fruits of papaya interrupt estrous cycle and induce abortions. The abortifacient property seems to decrease as the fruit becomes stale or ripe. Exogenous progesterone counteracts partially the adverse effects on pregnancy and the surviving foeti are without any distinct malformations.     

Flavonoids from flowers of Malva crispa L. (Malvaceae)

The following flavonoids were isolated and identified from the flowers of Malva crispa L.: kaempferol 3-O-beta-glucopyranoside, 3-O-(6"-tran-p-coumaroyl)-beta-D-glucopyranoside, 7-O-beta-D-glucopyranoside, 3-O-alpha-L-rhamnopyranosyl (1-->6)-beta-D-glucopyranoside and 3,7-O-diglucoside as well as quercetin 3-O-beta-D-glucopyranoside, 3-O-alpha-L-rhamnopyranosyl (1-->6) -beta-D-glucopyranoside and apigenin 7-O-beta-D-glucopyranoside. Their structures were established by chemical analysis, UV, 1H and 13C NMR spectrometry.     

Flavonoid compounds in the flowers of Abutilon indicum (L.) Sweet (Malvaceae)

Seven flavonoid compounds: luteolin, chrysoeriol, luteolin 7-O-beta-glucopyranoside, chrysoeriol 7-O-beta-glucopyranoside, apigenin 7-O-beta-glucopyranoside, quercetin 3-O-beta-glucopyranoside, quercetin 3-O-alpha-rhamnopyranosyl (1 --> 6)-beta-glucopyranoside, were isolated and identified from the flowers of Abutilon indicum (L.) Sweet (Malvaceae).     

Twenty-eight days repeated oral dose toxicity study of gemifloxacin in Wistar albino rats

The purpose of this study was to investigate the potential toxicity of gemifloxacin by 28-day repeated oral dose in Wistar albino rats. The test article, was administered daily by gavage to male and female rats at dose levels of 0, 50, 100, 200 mg/kg/day. At the end of treatment period, 12 rats/sex/group was sacrificed, while six extra rats/sex in the vehicle control and highest dose groups sacrificed after 14 days recovery period. During the treatment and recovery periods, clinical signs, mortality, body weights, food and water consumption, ophthalmoscopy, urinalysis, phototoxicity, hematology, serum biochemistry, synovial fluid biochemistry, electrocardiogram (ECG), gross findings, organ weights, microscopic examination of synovial fluid, and histopathology were examined. Hematological and serum biochemical investigations revealed a dose-dependent increase in the total white blood cell (WBC), total bilirubin (T-BIL), glucose (GLU), alanine aminotransferase (ALT) and significant decreases in total protein (TP) were observed in both sexes at the same dose, at the end of treatment period, but the levels returned toward normal during the recovery period. Histopathology of talar joint showed that erosion of the articular surface of that joint in both sexes at the end of treatment period at the dose level of 200 mg/kg/day. Degenerative changes in tendinocytes were observed in Achilles tendon of both sexes at the high dose level at the end of treatment period. In histopathological study shows partial effacement of liver architecture and focal ulceration in gastric mucosa at the high dose level at the end of treatment period. Based on these results, it was concluded that 28 days repeated oral dose of gemifloxacin caused increases in the liver weight, WBC count, T-BIL, glucose level, ALT, decreasing the TP, cause chronic hepatitis and acute gastritis, erosion of the articular surface of joint and histopathologic changes in Achilles tendon in rats at the dose level of 200 mg/kg/day.     

The effect of high-fat diet-induced obesity on cardiovascular toxicity in Wistar albino rats

The consumption of a high-fat diet (HFD) is considered a risk factor for obesity development. Nonetheless, a causal role of dietary fat has never been documented, because of inadequate animal models. In our study, one group of rats was fed with standard rat diet, while other group of rats fed with high-fat diet for 4 weeks. After 4 weeks of feeding, the hemodynamic parameters in the rats fed with HFD were significantly increased as compared with control rats. Rats fed with HFD had elevated levels of serum lipids, insulin, leptin, glucose and apolipoprotein B. Lipid peroxides and caspase-3 levels were increased while serum apolipoprotein A1 and antioxidant enzymes levels in heart tissues were decreased in HFD-induced obesity in rats as compared to normal healthy control rats fed on standard rat pellet diet. This model of diet-induced obesity will be a useful tool for studying the mechanisms by which dietary fat induces the obesity in humans.     

Protective effect of atorvastatin on bone tissue in orchidectomised male albino Wistar rats

Recent studies have shown that atorvastatin influences bone metabolism. We investigated its bone protective effect in orchidectomised rats after 12 weeks of treatment. Eight-week-old rats were divided into 3 groups: sham-operated group, control group after orchidectomy and experimental group after orchidectomy with atorvastatin administration (12 mg/kg/day). Bone mineral density and bone marker concentrations of aminoterminal propeptide of procollagen type I (PINP), osteoprotegerin (OPG), insulin-like growth factor 1 (IGF-1) in serum, and carboxy-terminal cross-linking telopeptide of type I collagen (CTX-I), bone alkaline phosphatase (BALP), bone morphogenetic protein 2 (BMP-2) in bone homogenate were measured. Total serum calcium and tibial calcium content was determined. Femurs were used for three-point bending test of the shaft and compression testing of the femoral neck. Bone markers (CTX-I, BALP, BMP-2) in control rats were higher vs. sham-operated rats. Atorvastatin reduced CTX-I, BMP-2 and OPG compared to controls. IGF-1 was decreased in control rats vs. sham-operated rats; atorvastatin increased IGF-1 vs. control rats. Atorvastatin exerts a positive effect on bone metabolism by increasing bone mineral density of the whole body, which had decreased under the effects of orchidectomy. Three-point bending test revealed an increase in maximal load values of the left femurs after atorvastatin administration compared to controls. The diameter of the left femur and length of both femurs were increased after atorvastatin administration compared to controls. Our findings suggest that atorvastatin has a beneficial effect on bone metabolism in orchidectomised rats by decreasing bone turnover, with resulting improvement in bone mineral density and bone biomechanical properties.     

Evaluation of anti-ulcer activity of Samanea saman (Jacq) merr bark on ethanol and stress induced gastric lesions in albino rats

Objective:

To evaluate the antiulcer activity of Samanea saman (Jacq) Merr bark on ethanol and stress induced gastric lesions in albino rats.

Materials and Methods:

Gastric lesions were induced in rats by oral administration of absolute ethanol (5 ml/kg) and stress induced by water immersion. The antiulcer activity of methanolic extract of Samanea saman (Jacq) Merr bark (100 mg/kg, 200 mg/kg, 400 mg/kg) was compared with standard drugs. The parameters studied were ulcer index, gastric juice volume, pH, free acidity and total acidity.

Result:

Samanea saman (Jacq) Merr showed a dose dependent curative ratio compared to ulcer control groups. The extract at 400 mg/kg showed significant anti ulcer activity which is almost equal to that of the standard drug in both models. The volume of acid secretion, total and free acidity was decreased and pH of the gastric juice was increased compared to ulcer control group.

Conclusions:

The present study indicates that Samanea saman (Jacq) Merr bark extracts have potential anti ulcer activity.     

Effect of scoparia dulcis (Sweet Broomweed) plant extract on plasma antioxidants in streptozotocin-induced experimental diabetes in male albino Wistar rats

Clinical research has confirmed the efficacy of several plants in the modulation of oxidative stress associated with diabetes mellitus. Scoparia dulcis plant extract is tried for prevention and treatment of diabetes mellitus induced experimentally by streptozotocin injection. A single dose of streptozotocin (45 mg/kg body weight) produced decrease in insulin, hyperglycemia, increased lipid peroxidation (Thiobarbituric reactive substances and lipid hydroperoxides) and decreased antioxidant levels (vitamin C, vitamin E, reduced glutathione, ceruloplasmin). Oral administration of an aqueous extract of Scoparia dulcis plant (200 mg/kg body weight) for 6 weeks to diabetic rats significantly increased the plasma insulin and plasma antioxidants and significantly decreased lipid peroxidation. The effect of Scoparia dulcis plant extract at 200 mg/kg body weight was better than that of glibenclamide, a reference drug.     

Cardiotoxic effects of dichlorvos (DDVP) in albino rats

Dichlorvos (O, O-dimethyl O-(2,2-dichlorovinyl phosphate: DDVP 76.6 X EC) an organophosphate pesticide had a profound effect on cardiac activity of albino rats. Adult male rats anesthetized with pentobarbitone were administered 30, 50, 70 and 90 mg/kg body weight of dichlorvos. The heart rate and electrocardiogram were monitored and acetylcholinesterase activity was measured in heart and brain. Dichlorvos produced abnormalities in ECG, decrease in heart rate, cardiac arrest and inhibition of cholinesterase activity. It is suggested that cardiotoxic effect of DDVP may be mediated by the accumulated acetylcholine as a result of cholinesterase inhibition.