Effects of Gundelia tournefortii L. on biochemical parameters, antioxidant activities and DNA damage in a rat model of experimental obesity / Efeitos de Gundelia tournefortii L. em parâmetros bioquímicos, atividades antioxidantes e danos ao DNA em um modelo de obesidade experimental de rato

The present study was designed to investigate the effects of Gundelia tournefortii L. plant extract on different tissues in terms of DNA damage, biochemical and antioxidant parameter values in rats with high-calorie diets. With this aim, Wistar albino male rats were divided into 4 groups containing 6 rats each and the study was completed over 12 weeks duration. At the end of the implementation process over the 12 weeks, rats were sacrificed and blood and tissue samples were obtained. Analyses were performed on blood and tissue samples. According to results for DNA damage (8-OHdG), in brain tissue the OG2 group was significantly reduced compared to the NC group. For MDA results in liver tissue, OG1 and OG2 groups were determined to increase by a significant degree compared to the control group, while the OG2 group was also increased significantly compared to the obese group. In terms of the other parameters, comparison between the groups linked to consumption of a high calorie diet (HCD) and administration of Gundelia tournefortii L. in terms of antioxidant activities and serum samples obtained statistically significant results. Gundelia tournefortii L. plant extracts had effects that may be counted as positive on antioxidant parameter activity and were especially identified to improve DNA damage and MDA levels in brain tissues. Additionally, consumption of Gundelia tournefortii L. plant extract in the diet may have antiobesity effects; thus, it should be evaluated for use as an effective weight-loss method and as a new therapeutic agent targeting obesity.

O presente estudo foi desenhado para investigar os efeitos do extrato da planta Gundelia tournefortii L. em diferentes tecidos em termos de danos ao DNA, valores de parâmetros bioquímicos e antioxidantes em ratos com dietas hipercalóricas. Com esse objetivo, ratos Wistar albinos machos foram divididos em 4 grupos contendo 6 ratos cada e o estudo foi concluído ao longo de 12 semanas de duração. No final desse processo de implementação, os ratos foram sacrificados e amostras de sangue e tecido foram obtidas. As análises foram realizadas em amostras de sangue e tecido. De acordo com os resultados para danos ao DNA (8-OHdG), no tecido cerebral o grupo OG2 foi significativamente reduzido em comparação com o grupo NC. Para os resultados de MDA no tecido hepático, os grupos OG1 e OG2 aumentaram significativamente em comparação ao grupo controle, enquanto o grupo OG2 também aumentou significativamente em comparação ao grupo obeso. Quanto aos demais parâmetros, a comparação entre os grupos ligados ao consumo de dieta hipercalórica (DC) e à administração de Gundelia tournefortii L. em termos de atividades antioxidantes e amostras de soro obteve resultados estatisticamente significativos. Os extratos de plantas de Gundelia tournefortii L. tiveram efeitos que podem ser considerados positivos na atividade dos parâmetros antioxidantes e foram especialmente identificados para melhorar os danos ao DNA e os níveis de MDA nos tecidos cerebrais. Além disso, o consumo de extrato vegetal de Gundelia tournefortii L. na dieta pode ter efeitos antiobesidade; portanto, deve ser avaliado para uso como um método eficaz de perda de peso e como um novo agente terapêutico voltado para a obesidade.

Deep skin wound healing potential of lavender essential oil and licorice extract in a nanoemulsion form: Biochemical, histopathological and gene expression evidences.

Cutaneous wound healing is one of the public health interests. This study aimed to investigate the effects of nanoemulsion cream containing lavender essential oil and licorice extract on the healing of deep skin wound in a rat model. Eighty-five male Wistar rats were randomly divided into five groups including untreated defects as negative control and defects treated with vehicle ointment, lavender essential oil and licorice extract in emulsion and nanoemulsion forms, and phenytoin 1% as the positive control with an excisional wound on the dorsal neck of each rat. On days 2, 7 and 14 oxidative stress factors were evaluated in wound tissue homogenates. The expression of transforming growth factor-ß (TGF-ß), and type I and type III collagen genes were evaluated. Also, wound tissue samples were processed for Hematoxylin & Eosin and Masson-Trichrome staining. Nanoemulsion reduced the wound area more than other groups significantly. Real-time PCR data demonstrated that nanoemulsion and phenytoin groups have shown the best result in increasing TGF-ß1, Type I and type III collagen genes expression compared to the other groups. Reduction in lipid peroxidation level and increasing in SOD and GPx activity was also significant in the nanoemulsion and phenytoin groups. The formation of granular tissue likewise the appearance of collagen in nanoemulsion and phenytoin groups were faster than the other groups. Nanoemulsion cream containing lavender essential oil and licorice extract exhibited a promising wound healing potential towards the excisional wound model in rats.

Genetic strain differences in platelet aggregation and thrombus formation of laboratory rats.

Rats are employed to investigate the role of platelets in thrombus formation under flow conditions in vivo and to evaluate the pre-clinical potential of antiplatelet drugs. While Wistar and Sprague-Dawley (SD) strains are commonly used in thrombosis models, a number of rat strains have been established. Each strain possesses genetically unique characteristics such as hypertension, hyperglycemia or hyperlipidemia. The appropriate selection of a strain might have advantages for physiological and pharmacological studies. Comparative investigation of platelet aggregation among laboratory strains of rats is useful for the development of thrombosis models. In the present study, platelet aggregation response in eight laboratory rat strains, ACI, Brown Norway (BN), Donryu, Fischer 344 (F344), LEW, SD, Wistar and WKAH, were compared. Considerable strain differences were observed in ADP-, collagen- and TRAP-induced platelet aggregation. SD and BN are high-platelet-aggregation strains, while F344 and ACI are low-response strains. In the arteriovenous shunt thrombosis model, SD formed larger thrombi than F344 and Wistar rats. In the FeCl(3)-induced thrombosis model with the carotid artery, the time to occlusion of SD was significantly shorter than of F344 and ACI rats. F344 and ACI rats had significantly increased bleeding times compared with SD rat. The present study demonstrates that there are considerable strain differences in platelet aggregation among laboratory rats, which reflect thrombus formation.

Two Wistar rat lines selectively bred for anxiety-related behavior show opposite reactions in elevated plus maze and fear-sensitized acoustic startle tests.

Two Wistar rat lines selectively bred for high (HAB), and low anxiety-related behavior (LAB) on the elevated plus maze were tested for the fear-sensitized acoustic startle response. The study of male rats from the F9 generation revealed a higher anxiety level of HAB rats on the elevated plus maze. However, the LAB rats displayed a higher baseline and fear-sensitized acoustic startle response compared to HAB rats, although the two rat lines did not differ in freezing duration during the interstimulus intervals in the startle experiment (neither before, nor after, footshocks). Counts of neurons immunoreactive for corticotropin-releasing factor and neuropeptide Y in amygdaloid nuclei did not reveal any differences between the two lines, which is in marked contrast to findings in the Roman rat lines. The data indicate that opposite types of anxiety/fear responses are elicited in HAB/LAB rats in the elevated plus maze and fear-sensitized startle tests. Moreover, the animals displayed a differential fear response in the startle experiment, as assessed by measuring the fear-sensitized startle response and freezing.

Hypothalamic and hippocampal release of serotonin in rats bred for hyper- or hypo-anxiety.

Microdialysis for measurement of serotonin in the paraventricular nucleus of the hypothalamus (PVN) and the dorsal hippocampus was performed under both basal and stimulated conditions, known to elicit differential behavioral and neuroendocrine responses in rats with inborn high (HAB) or low (LAB) anxiety-related behavior. We studied the release of hypothalamic and hippocampal serotonin in response to elevated platform exposure and forced swim stress, a mild emotional and a combined emotional and physical stressor, respectively. The data suggest that serotonin release patterns may depend on the inborn level of anxiety, the brain area dialyzed, and the stressor the animals were exposed to. Under basal conditions, no differences in serotonin release in either the PVN or dorsal hippocampus were observed between HAB and LAB rats. While in the PVN open platform exposure failed to change the release of serotonin, forced swim stress induced an increase in both HAB (p = 0.0001) and LAB (p = 0.01) rats with a significantly greater effect in the former (p = 0.027). In the dorsal hippocampus, only LABs, but not HABs, responded to the elevated platform exposure by enhancing the release of serotonin (p = 0.01). Also, forced swim stress increased hippocampal serotonin only in LAB (p = 0.002), but not HAB, rats probably indicating an involvement of hippocampal serotonin in locomotion and active stress coping. It remains to be shown to what extent the differences in serotonin release contribute to neuroendocrine and behavioral differences between HAB and LAB rats.

Oral triacylglycerols regulate plasma glucagon-like peptide-1(7-36) and insulin levels in normal and especially in obese rats.

In a previous study of glucose tolerance, plasma insulin levels were greatly elevated in genetically obese Wistar fatty rats but not lean rats fed a diet containing polyunsaturated fatty acids. In the present study, triacylglycerol-regulation of levels of circulating insulin and glucagon-like peptide-1 (7-36) (GLP-1) has been investigated in these rats. In the glucose tolerance test, the two plasma insulin peaks appeared in obese and lean rats intubated with glucose + corn oil, at 15- 30 min and 4 h, whereas only the first peak appeared in rats intubated with glucose alone, although the glucose response did not differ. After intubation of corn oil only, the insulin peak at 15 min was not detected but the peak at 4h was large. The two plasma GLP-1 peaks appeared 15 min and 4 h after intubation of glucose + corn oil similarly to the insulin responses, although the first peak was small and the second peak was very large. A small peak at 15 min was not significant in rats intubated glucose alone and no peak was seen at 4 h. The GLP-1 concentrations were significantly higher in the following order: portal vein > inferior vena cava > tail vein. The plasma GLP-1 increment in response to oral triacylglycerols was significantly higher in obese rats than in lean rats as was the insulin increment. Thus, oral triacylglycerols (possibly polyunsaturated) appeared to act at the gut lumen to stimulate GLP-1 secretion, which may be responsible for the second (4 h) insulin peak.