Zakiah Jubri

Perturbation of cellular immune functions in cigarette smokers and protection by palm oil vitamin E supplementation

BackgroundCigarette smoke contains free radicals and an have adverse effect to the immune system. Supplementation of palm oil vitamin E (palmvitee), is known has antioxidant properties is thought to be beneficial for system immune protection against free radicals activity. The objective of the study was to determine the effect of palmvitee supplementation on immune response in smokers.MethodsThis study involved a group of smokers and nonsmokers who received 200 mg/day palmvitee and placebo for the control group. Blood samples were taken at 0, 12 and 24 weeks of supplementation. Plasma tocopherol and tocotrienol were determined by HPLC, lymphocyte proliferation by lymphocyte transformation test (LTT) and enumeration of lymphocytes T and B cells by flow cytometry. Statistical analysis was performed by Mann–Whitney U-test for non-parametric data distribution and correlation among the variables was examined by Spearman.ResultsPlasma tocopherol and tocotrienol were increased in vitamin E supplemented group as compared to placebo group. Urine cotinine levels and serum α1-antitrypsin were significantly higher in smokers compared to nonsmokers. Lymphocyte proliferation induced by PHA showed an increasing trend with palmvitee supplementation in both smokers and nonsmokers. Natural killer cells were decreased; CD4+ cells and B cells were increased in smokers compared to nonsmokers but were unaffected with vitamin E supplementation except in the percentage of B cells which were increased in nonsmokers supplemented palmvitee compared to placebo. CD4+/CD8+ ratio was increased in smokers compared to nonsmokers. The high TWBC count observed in smokers correlated with the increased CD4+ and B cells.ConclusionsSmoking caused alterations in certain immune parameters and palmvitee supplementation tended to cause an increase in lymphocytes transformation test but had no effect on CD3+, CD4+, CD8+, NK cells and B cells except B cells percentage in nonsmokers.

Manuka honey protects middle-aged rats from oxidative damage

OBJECTIVE: This study aimed to determine the effect of manuka honey on the oxidative status of middle-aged rats. METHOD: Twenty-four male Sprague-Dawley rats were divided into young (2 months) and middle-aged (9 months) groups. They were further divided into two groups each, which were either fed with plain water (control) or supplemented with 2.5 g/kg body weight of manuka honey for 30 days. The DNA damage level was determined via the comet assay, the plasma malondialdehyde level was determined using high performance liquid chromatography, and the antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, glutathione peroxidase and catalase) were determined spectrophotometrically in the erythrocytes and liver. The antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl and ferric reducing/antioxidant power assays, and the total phenolic content of the manuka was analyzed using UV spectrophotometry and the Folin-Ciocalteu method, respectively. RESULTS: Supplementation with manuka honey reduced the level of DNA damage, the malondialdehyde level and the glutathione peroxidase activity in the liver of both the young and middle-aged groups. However, the glutathione peroxidase activity was increased in the erythrocytes of middle-aged rats given manuka honey supplementation. The catalase activity was reduced in the liver and erythrocytes of both young and middle-aged rats given supplementation. Manuka honey was found to have antioxidant activity and to have a high total phenolic content. These findings showed a strong correlation between the total phenolic content and antioxidant activity. CONCLUSIONS: Manuka honey reduces oxidative damage in young and middle-aged rats; this effect could be mediated through the modulation of its antioxidant enzyme activities and its high total phenolic content. Manuka honey can be used as an alternative supplement at an early age to improve the oxidative status.

Involvement of Inflammation and Adverse Vascular Remodelling in the Blood Pressure Raising Effect of Repeatedly Heated Palm Oil in Rats

Oil thermoxidation during deep frying generates harmful oxidative free radicals that induce inflammation and increase the risk of hypertension. This study aimed to investigate the effect of repeatedly heated palm oil on blood pressure, aortic morphometry, and vascular cell adhesion molecule-1 (VCAM-1) expression in rats. Male Sprague-Dawley rats were divided into five groups: control, fresh palm oil (FPO), one-time-heated palm oil (1HPO), five-time-heated palm oil (5HPO), or ten-time-heated palm oil (10HPO). Feeding duration was six months. Blood pressure was measured at baseline and monthly using tail-cuff method. After six months, the rats were sacrificed and the aortic arches were dissected for morphometric and immunohistochemical analyses. FPO group showed significantly lower blood pressure than all other groups. Blood pressure was increased significantly in 5HPO and 10HPO groups. The aortae of 5HPO and 10HPO groups showed significantly increased thickness and area of intima-media, circumferential wall tension, and VCAM-1 than other groups. Elastic lamellae were disorganised and fragmented in 5HPO- and 10HPO-treated rats. VCAM-1 expression showed a significant positive correlation with blood pressure. In conclusion, prolonged consumption of repeatedly heated palm oil causes blood pressure elevation, adverse remodelling, and increased VCAM-1, which suggests a possible involvement of inflammation.

Gelam honey protects against gamma-irradiation damage to antioxidant enzymes in human diploid fibroblasts.

The present study was designed to determine the radioprotective effects of Malaysian Gelam honey on gene expression and enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) of human diploid fibroblasts (HDFs) subjected to gamma-irradiation. Six groups of HDFs were studied: untreated control, irradiated HDFs, Gelam honey-treated HDFs and HDF treated with Gelam honey pre-, during- and post-irradiation. HDFs were treated with 6 mg/mL of sterilized Gelam honey (w/v) for 24 h and exposed to 1 Gray (Gy) of gamma rays at the dose rate of 0.25 Gy/min. Gamma-irradiation was shown to down-regulate SOD1, SOD2, CAT and GPx1 gene expressions (p < 0.05). Conversely, HDFs treated with Gelam honey alone showed up-regulation of all genes studied. Similarly, SOD, CAT and GPx enzyme activities in HDFs decreased with gamma-irradiation and increased when cells were treated with Gelam honey (p < 0.05). Furthermore, of the three different stages of study treatment, pre-treatment with Gelam honey caused up-regulation of SOD1, SOD2 and CAT genes expression and increased the activity of SOD and CAT. As a conclusion, Gelam honey modulates the expression of antioxidant enzymes at gene and protein levels in irradiated HDFs indicating its potential as a radioprotectant agent.

Protective effects of gelam honey against oxidative damage in young and aged rats.

Aging is characterized by progressive decline in physiological and body function due to increase in oxidative damage. Gelam honey has been accounted to have high phenolic and nonphenolic content to attenuate oxidative damage. This study was to determine the effect of local gelam honey on oxidative damage of aged rats. Twenty-four male Spraque-Dawley rats were divided into young (2 months) and aged (19 months) groups. Each group was further divided into control (fed with plain water) and supplemented with 2.5 mg/kg body weight of gelam honey for 8 months. DNA damage level was determined by comet assay and plasma malondialdehyde (MDA) by high performance liquid chromatography (HPLC). The activity of blood and cardiac antioxidant enzymes was determined by spectrophotometer. The DNA damage and MDA level were reduced in both gelam honey supplemented groups. Gelam honey increases erythrocytes CAT and cardiac SOD activities in young and cardiac CAT activity in young and aged groups. The DNA damage was increased in the aged group compared to young group, but reduced at the end of the study. The decline of oxidative damage in rats supplemented with gelam honey might be through the modulation of antioxidant enzyme activities.

Critical factors for lentivirus‑mediated PRDX4 gene transfer in the HepG2 cell line

Optimization of critical factors affects transduction efficiency and is able to reduce reagent consumption. The present study aimed to determine the optimum transduction conditions of small hairpin (sh)RNA against peroxiredoxin 4 (PRDX4) in the HepG2 cell line. Cell viability assays were conducted based on serum condition, incubation time, polybrene concentration and antibiotic dose selection. Non-targeting control shRNA was transduced into HepG2 cells in a 5-fold serial dilution, and colonies positive for green fluorescent protein were counted using ImageJ software. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were performed to validate PRDX4 expression. The optimum cell density for transduction was 5.0×103 cells/well in 96-well plates to achieve 40 to 50% confluency the following day. The transduction media consisted of 10% fetal bovine serum (FBS) and 12 µg/ml polybrene, and was used to dilute lentiviral particles at a functional titer of 4.9×105 TU/ml for multiplicity of infection (MOI) of 20, 15 and 10, for 24 h of incubation. Selection with 7 µg/ml puromycin was performed in transduced cells. shRNA 3 was revealed to inhibit PRDX4 mRNA and protein expression. In conclusion, PRDX4 was successfully silenced in 5.0×103 HepG2 cells cultured with 10% FBS and 12 µg/ml polybrene, at a 4.9×105 TU/ml functional titer for MOI of 20, 15 and 10.

Modulation of age related protein expression changes by gelam honey in cardiac mitochondrial rats

&NA; Aging is characterized by progressive decline in biochemical and physiological functions. According to the free radical theory of aging, aging results from oxidative damage due to the accumulation of excess reactive oxygen species (ROS). Mitochondria are the main source of ROS production and are also the main target for ROS. Therefore, a diet high in antioxidant such as honey is potentially able to protect the body from ROS and oxidative damage. Gelam honey is higher in flavonoid content and phenolic compounds compared to other local honey. This study was conducted to determine the effects of gelam honey on age related protein expression changes in cardiac mitochondrial rat. A total of 24 Sprague‐Dawley male rats were divided into two groups: the young group (2 months old), and aged group (19 months old). Each group were then subdivided into two groups: control group (force‐fed with distilled water), and treatment group (force‐fed with gelam honey, 2.5 g/kg), and were treated for 8 months. Comparative proteomic analysis of mitochondria from cardiac tissue was then performed by high performance mass spectrometry (Q‐TOF LCMS/MS) followed by validation of selected proteins by Western blotting. Proteins were identified using Spectrum Mill software and were subjected to stringent statistical analysis. A total of 286 proteins were identified in the young control group (YC) and 241 proteins were identified in the young gelam group (YG). In the aged group, a total of 243 proteins were identified in control group (OC), and 271 proteins in gelam group (OG). Comparative proteome profiling identified 69 proteins with different abundance (p < 0.05) in OC when compared to YC, and also in YG when compared to YC. On the other hand, 55 proteins were found to be different in abundance when comparing OG with OC. In the aged group, gelam honey supplementation affected the relative abundance of 52 proteins with most of these proteins showing a decrease in the control group. Bioinformatics analysis showed that the majority of the affected proteins were involved in the respiratory chain (OXPHOS) which play an important role in maintaining mitochondrial function.

THE EFFECTIVENESS OF OBJECTIVE STRUCTURED PERFORMANCE EVALUATION (OSPE)-BASED SETTING VERSUS CONVENTIONAL PRACTICAL IN ENHANCING KNOWLEDGE AMONG MEDICAL STUDENTS

Introduction: Flipped classroom is currently adapted in the medical curricula where students are required to prepare for class activity by utilizing technology to gather knowledge and subsequently to engage in teamwork to solve cases and practice problems during classes. Objective Structured Performance Evaluation (OSPE)-based setting is one of the innovation in flipped classroom to enhance teaching and learning experience in replacing a conventional practical. Objectives: To evaluate the effectiveness of OSPE-based setting versus conventional practical in enhancing medical students’ knowledge in medical genetics. Methods: Teaching materials were uploaded on University Kebangsaan Malaysia (UKM) learning platform, iFolio a week before the session started. Students are required to read the materials and watch videos in preparation. There were 10 OSPE stations which consist of questions on gene mutations and mutational analysis. Forty groups of Year One Medical students (4 students per group) participated in this study and they were required to answer every station. Each station must be completed within 10 minutes. Marks were collected at the end of the session and their experience were collated through online questionnaire. Subsequently, students’ performance were tracked at the end of module examination. Results: Among 40 groups participated in the OSPE session, the mean of the total marks scored is 92.025%. Majority of the students agreed that OSPE mode of learning medical genetics in replacement of practical mode increased their understanding on genetic mutations and mutational analysis and they are more prepared for the end of module examination. Their average marks increased in the end of module exam (68.4 ± 11.6) when compared to the previous session (59.3 ± 10.4). Conclusions: Flipped classroom and OSPE mode of learning can enhance and improve medical students’ interest in learning and their self-learning abilities. It is an effective teaching model that needs to be further studied and incorporated in medical school setting.