Impact of Open Inquiry in Science Education on Working Memory, Saliva Cortisol and Problem Solving Skill

AbstractThe purpose of this study was to compare working memory, saliva cortisol hormone, and problem solving skill between students in two different contexts: Open Inquiry and Conventional Learning. The participants were consisted of two classes of 86 10th grade students, from one school during the 0211 academic year. A pretest - posttest control group design was used in the experiment. The tools were consisted of1) salivary cortisol assay 0)The computerized assessment battery test 3)problem solving skill test. The collected data were analyzed by arithmetic mean, sd., t – test, and Hotelling T2. The findings revealed that: after intervention 1) student's saliva cortisol hormone in Open Inquiry group was lower than Conventional group at .05 level of significance 2) student's working memory in Open Inquiry group were higher than students in Conventional group at .05 level of significance, but unable to proof about the difference of student's problem solving ability

Zingiber officinale Mitigates Brain Damage and Improves Memory Impairment in Focal Cerebral Ischemic Rat

Cerebral ischemia is known to produce brain damage and related behavioral deficits including memory. Recently, accumulating lines of evidence showed that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, possible protective effect of Zingiber officinale, a medicinal plant reputed for neuroprotective effect against oxidative stress-related brain damage, on brain damage and memory deficit induced by focal cerebral ischemia was elucidated. Male adult Wistar rats were administrated an alcoholic extract of ginger rhizome orally 14 days before and 21 days after the permanent occlusion of right middle cerebral artery (MCAO). Cognitive function assessment was performed at 7, 14, and 21 days after MCAO using the Morris water maze test. The brain infarct volume and density of neurons in hippocampus were also determined. Furthermore, the level of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in cerebral cortex, striatum, and hippocampus was also quantified at the end of experiment. The results showed that cognitive function and neurons density in hippocampus of rats receiving ginger rhizome extract were improved while the brain infarct volume was decreased. The cognitive enhancing effect and neuroprotective effect occurred partly via the antioxidant activity of the extract. In conclusion, our study demonstrated the beneficial effect of ginger rhizome to protect against focal cerebral ischemia

Cognitive-Enhancing Effect of Quercetin in a Rat Model of Parkinson's Disease Induced by 6-Hydroxydopamine

Oxidative stress has been reported to induce cognitive impairment in Parkinson's disease. This paper aimed to determine the effect of quercetin, a substance possessing antioxidant activity, on the cognitive function in a rat model of Parkinson's disease. Male Wistar rats, weighing 200–250 g, were orally given quercetin at doses of 100, 200, 300 mg/kg BW once daily for a period of 14 days before and 14 days after the unilateral lesion of right substantia nigra induced by 6-hydroxydopamine (6-OHDA). Their spatial memory was assessed at 7 and 14 days of treatment and neuron density was determined, malondialdehyde (MDA) level, the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were evaluated at the end of the experiment. In addition, the activity of acetylcholinesterase (AChE) was also measured. It was found that all doses of quercetin enhanced spatial memory. Therefore, it is suggested that the cognitive-enhancing effect of quercetin occurs partly because of decreased oxidative damage resulting in increased neuron density

Chemical Profiling of Essential Oil Composition and Biological Evaluation of Anethum graveolens L. (Seed) Grown in Thailand

In this study, the essential oil of Anethum graveolens L. seed (AEo) was studied for their chemical composition, antioxidant potential, antimicrobial and anticancer activities. AEo was obtained from hydro-distillation and their composition was analyzed by GC-MS.  The major compositions of AEo are D-carvone, carvone, dill apiol and limonene. AEo was investigated for antioxidant activity by DPPH, ABTS, FRAP assay and measured total phenolic content by Folin-Ciocalteu colorimetric method.  Agar-well diffusion assay was used to study the anti-microbial activity and also agar-dilution and broth-micro dilution techniques were employed for minimum inhibitory concentration (MIC) determination. In addition, the cytotoxicity and anticancer activity were evaluated on Green fluorescent protein (GFP) and Resazurin micro plate assay (REMA).  The results showed that AEo exhibited high total phenolic content (GAE= 4.5746 mg/mL) and antioxidant activities on DPPH (TEAC= 52.5391 mg/mL), ABTS (TEAC= 1.5936 mg/mL) and FRAP assay (TEAC= 0.5469 mg/mL) and also showed potent activity against Staphylococcus aureus and Escherichia coli at the MIC= 5.99 mg/mL.  Furthermore, AEo presented non-cytoxicity in normal cell whereas it exhibited greatly anti-cancer activity on KB-Oral cavity and MCF7-Breast cancer cells. Keywords: Anethum graveolens L., antioxidant activity, antimicrobial activity, anticancer activity, chemical composition

Antiosteoporotic Effect of Combined Extract of Morus alba

Due to the limitation of osteoporosis therapy, the alternative therapies from natural sources have been considered. In this study, we aimed to determine the antiosteoporotic effect of the combined extract of Morus alba and Polygonum odoratum leaves. Ovariectomized rats, weighing 200–220 g, were orally given the combined extract at doses of 5, 150, and 300 mg·kg−1 BW for 3 months. At the end of study, blood was collected to determine serum osteocalcin, calcium, and alkaline phosphatase level. In addition, tibia bone was isolated to determine bone oxidative stress markers, cortical bone thickness, and density of osteoblast. The combined extract decreased oxidative stress and osteoclast density but increased osteoblast density and cortical thickness. The elevation of serum calcium, alkaline phosphatase, and osteocalcin was also observed. These results suggested the antiosteoporotic effect of the combined extract via the increased growth formation together with the suppression of bone resorption. However, further studies concerning chronic toxicity and the underlying mechanism are required

Zingiber officinale Improves Cognitive Function of the Middle-Aged Healthy Women

The development of cognitive enhancers from plants possessing antioxidants has gained much attention due to the role of oxidative stress-induced cognitive impairment. Thus, this study aimed to determine the effect of ginger extract, or Zingiber officinale, on the cognitive function of middle-aged, healthy women. Sixty participants were randomly assigned to receive a placebo or standardized plant extract at doses of 400 and 800 mg once daily for 2 months. They were evaluated for working memory and cognitive function using computerized battery tests and the auditory oddball paradigm of event-related potentials at three different time periods: before receiving the intervention, one month, and two months. We found that the ginger-treated groups had significantly decreased P300 latencies, increased N100 and P300 amplitudes, and exhibited enhanced working memory. Therefore, ginger is a potential cognitive enhancer for middle-aged women

Centella asiatica Improves Physical Performance and Health-Related Quality of Life in Healthy Elderly Volunteer

Recently, oxidative stress has been reported to contribute an important role in the decline of physical function as age advances. Numerous antioxidants can improve both physical and psychological performances resulting in the increase of health-related quality of life (HQOL). Therefore, we hypothesized that Centella asiatica, a medicinal plant reputed for nerve tonic, strength improvement and antioxidant activity, could improve the physical performance and HQOL especially in the physical satisfaction aspect, of the healthy elderly volunteer. To test this hypothesis, a double-blind, placebo-controlled, randomized trial was performed. Eighty healthy elderly were randomly assigned to receive placebo or standardized extract of C. asiatica at doses of 250, 500 and 750 mg once daily for 90 days. The subjects were evaluated to establish baseline data of physical performance using 30-s chair stand test, hand grip test and 6-min walk test. The health-related quality of life was assessed using SF-36. These assessments were repeated every month throughout the 3-month experimental period using the aforementioned parameters. Moreover, 1 month after the cessation of C. asiatica treatment, all subjects were also evaluated using these parameters again. The results showed that after 2 months of treatment, C. asiatica at doses of 500 and 750 mg per day increased lower extremity strength assessed via the 30-s chair stand test. In addition, the higher doses of C. asiatica could improve the life satisfaction subscale within the physical function subscale. Therefore, the results from this study appear to support the traditional reputation of C. asiatica on strength improvement, especially in the lower extremities of the elderly. C. asiatica also possesses the potential to be a natural resource for vigor and strength increase, in healthy elderly persons. However, further research is essential

Neuroprotective and Memory-Enhancing Effect of the Combined Extract of Purple Waxy Corn Cob and Pandan in Ovariectomized Rats

The neuroprotectant and memory enhancer supplement for menopause is required due to the side effects of hormone replacement therapy. Since purple waxy corn cob and pandan leaves exert antioxidant and acetylcholinesterase inhibition (AChEI) effects, we hypothesized that the combined extract of both plants (PCP) might provide synergistic effect leading to the improved brain damage and memory impairment in experimental menopause. To test this hypothesis, female Wistar rats were ovariectomized bilaterally and orally given various doses of the functional drink at doses of 20, 40, and 80 mg/kg for 28 days. The animals were assessed nonspatial memory using object recognition test every 7 days throughout the study period. At the end of study, they were assessed with oxidative stress status, AChEI, neuron density, and ERK1/2 signal in the prefrontal cortex (PFC). Interestingly, all doses of PCP increased object recognition memory and neuron density but decreased oxidative stress status in PFC. Low dose of PCP also decreased AChE activity while medium dose of PCP increased phosphorylation of ERK1/2 in PFC. Therefore, the improved oxidative stress status and cholinergic function together with signal transduction via ERK in PFC might be responsible for the neuroprotective and memory-enhancing effects of PCP