Abstract

Background: Ginkgo biloba extract (GbE) is known to contain several bioactive compounds and exhibits free radical scavenging activity. Parkinson's Disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons and is associated with oxidative stress, neuroinflammation and apoptosis.

Objective: The current study aimed to investigate the neuroprotective effect of GbE in a rat model of PD induced by rotenone (ROT; a neurotoxin).

Methods: Twenty-four male albino rats were randomly divided into four groups of six rats each: normal control, GbE treated, toxin control (ROT treated) and GbE+ROT group.

Results: Oral administration of ROT (2.5 mg/kg b.w.) for 50 days caused an increased generation of lipid peroxidation products and significant depletion of reduced glutathione, total thiol content and activities of enzymatic antioxidants, i.e., superoxide dismutase and glutathione peroxidase in the brains of treated rats. Furthermore, ROT caused an elevation in acetylcholinesterase, interleukin-1β, interleukin- 6 and tumor necrosis factor-α and a significant reduction in dopamine in the stratum and substantia nigra. Immunohistochemical results illustrated that ROT treatment reduced the expression of tyrosine hydroxylase (TH). GbE treatment (150 mg/kg b.w./day) significantly reduced the elevated oxidative stress markers and proinflammatory cytokines and restored the reduced antioxidant enzyme activities, DA level and TH expression. These results were confirmed by histological observations that clearly indicated a neuroprotective effect of GbE against ROT-induced PD.

Conclusion: GbE mitigated ROT-induced PD via the inhibition of free-radical production, scavenging of ROS, and antioxidant enhancement.

Keywords: Ginkgo biloba; Parkinson's disease; ROT treatment; neuroprotection; oxidative stress; rotenone.

Abstract: The effects of early-life fructose consumption on hepatic signaling pathways and their

relation to the development of metabolic disorders in later life are not fully understood. To investigate

whether fructose overconsumption at a young age induces alterations in glucocorticoid signaling

that might contribute to development of metabolic disturbances, we analyzed glucocorticoid

receptor hormone-binding parameters and expression of its target genes involved in gluconeogenesis

(phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) and lipid metabolism (lipin-1),

as well as redox and inflammatory status in the liver of female rats subjected to a fructose-rich

diet immediately after weaning. The fructose diet increased hepatic corticosterone concentration,

11-hydroxysteroid dehydrogenase type 1 level, glucocorticoid receptor protein level and

hormone-binding activity, as well as lipin-1 level. The expression of glucose-6-phosphatase was

reduced in fructose-fed rats, while phosphoenolpyruvate carboxykinase remained unaltered.

The fructose-rich diet increased the level of fructose transporter GLUT2, while the expression

of fructolytic enzymes fructokinase and aldolase B remained unaltered. The diet also affected

pro-inflammatory pathways, but had no effect on the antioxidant defence system. In conclusion,

a fructose-rich diet applied immediately after weaning promoted lipogenesis and enhanced hepatic

glucocorticoid signaling, possibly to protect against inflammatory damage, but without an effect on

gluconeogenesis and antioxidant enzymes. Yet, prolonged treatment might ultimately lead to more

pronounced metabolic disturbances.

APSTRACT

 The present study investigated EFL Libyan undergraduate students’ attitude towards effect of note taking strategies on academic achievement. The study also explored whether there is a significant difference in students’ attitude towards effect of note taking strategies on academic achievement regarding to gender. A total of 80 participants were all EFL undergraduate students from Tripoli University. The data were collected by a questionnaire and analyzed statistically by SPSS Program. The findings indicated that the participants showed positive attitudes towards the benefit of note taking strategies on academic achievement i.e. note taking helps to improve academic achievement. It was also found that there is not a statistically significant difference in students’ attitude towards the effect of note taking strategies on academic achievement due to gender. In the light of above results, some recommendations are finally provided for teachers and students to consider. Key words: note taking strategies, academic achievement, attitude, gender.

The Role of Website Visual Design in Predicting Consumers' Purchase Intention: an Empirical Study in a B2C Environment

Long time ago, phytotherapy constitutes a major health practice all over the world. Many medicinal plants such as Saussurea lappa (S. lappa) has wide beneficial roles. This study was contrived to explore the antiphlogistic effect of S. lappa roots extract treated by 100% ethanol solvent. Carrageenan induced paw edema model was used to carry out the experiment on laboratory Wistar albino rats. Before testing extract on animals, it was necessary to check the safety of the plant according to performed testing conditions albeit S. lappa is generally recognized as safe plant, hence the acute oral toxicity test by the fixed-dose procedure method (FDP) was performed. Roots’ ethanol extract tested at two doses (100 and 200 mg/kg), ibuprofen used as a positive control, and negative control was distilled water. SPSS statistical analysis was undertaken to check the variance between tested groups via one-way analysis of variance, then pursued by Tukey and Dunnett two-sided tests. FDP experiment disclosed that extract was safe for further in-vivo testing for the dose up to 2000 mg/kg < LD50 < 5000 mg/kg, without reporting of any toxicity signs. The extract manifested a significant (P < 0.05 - 0.01) anti-inflammatory effects at both tested doses. The ethanol extract exposed a clear decrease in edema size by a percentage of 13.73 % at 200 mg/kg dose when compared to that of standard agent which minimized edema by 22.79 %. It is presumed that plant roots contain phytoconstituents that are responsible to share this effect like sesquiterpene lactones (dehydrocostus lactone and cynaropicrin mainly), in which many researches revealed that such compounds which found in many other plants have a potent anti-inflammatory action.