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Pterostilbene is a potent antioxidant and anti-inflammatory agent. However, its chemopreventive effects via anti-tyrosinase activity and inhibitory effects on melanin content have not been reported previously. Hence, this study aimed to investigate the anti-melanogenic activity of pterostilbene on UVB-irradiated B164A5 mouse melanoma cells. The effects of pterostilbene and resveratrol on cell viability were determined by MTT assay, whereas melanin content and tyrosinase assay were employed to assess melanogenesis activity. Western blot analysis was performed to determine the tyrosinase expression. Based on the MTT assay, the IC50 value of pterostilbene on UVB-irradiated B164A5 cells was 34.0 ± 3.43 μM, in comparison to resveratrol (>100 μM). Next, 5 and 10 μM pterostilbene showed a significant dose-dependent inhibition ( P < .01) of tyrosinase activity in UVB-irradiated B164A5 cells at 37.14 ± 2.71% and 58.36 ± 6.8%, respectively. The findings from the tyrosinase assay also confirmed the downregulation of tyrosinase expression in UVB-irradiated B164A5 cells as measured by Western blot analysis. Finally, 10 μM pterostilbene showed a significantly decreased melanin content ( P < .01) in UVB-irradiated B164A5 cells, at 27.34 ± .98 μg/mL. In conclusion, pterostilbene showed anti-melanogenic activity that was 10 times more potent than resveratrol in the UVB-irradiated B164A5 cell.

Tahfiz school is an institution that specialises in educating students to memorize and recite the whole Al-Quran. Memorizing the Al-Quran by rote learning will activate the brain to improve the brain ability to process, store information and build memory. The presence of heavy metals affects the nervous system and interferes with the function of the central and peripheral nervous system which will then cause the impairment of mental and cognitive function. The ability to learn, remember or memorize, use of language and to understand something may be disrupted and cause small decrease in IQ and attention. Cross-sectional studies was conducted to measure and to determine the correlation between the levels of heavy metals, Al-Quran memorization and intelligence (IQ) among students in selected tahfiz schools compared to non-tahfiz schools in Selangor. Levels of heavy metals in nail and hair samples were analyzed by using the Inductively Coupled Plasma Mass Spectrometry (ICP-MS). WASI-II test for intelligence was used to measure the student’s IQ. Questionnaires was used to obtain demographic data and was analyzed by using the SPSS version 23.0. Based on the Pearson correlation test, there was a very weak negative correlation and significant relationship between manganese in the hair samples with the level of Al-Quran memorization (r= -0.178, p=0.017). In addition, there was a weak positive correlation but significant relationship between the level of intelligence (IQ) with the level of Al-Quran memorization (r= 0.375, p=

Dietary antioxidant supplements such as L-glutathione have gained considerable attention in dermatology and cosmeceutical fields. L-glutathione possesses antiaging, antimelanogenic, antioxidant, and anticancer properties. This study aimed to investigate the inhibitory effects of L-glutathione on melanogenesis activity and oxidative stress in ultraviolet B (UVB)-irradiated BALB/c mice. Eighteen female BALB/c mice were randomly divided into 3 groups: a control group (n=6), a group without UVB irradiation and L-glutathione administration; a UVB irradiated group (n=6), a group irradiated with a UVB dose of 250 mJ/cm2 for 3 min; and a treatment group (n=6), a group irradiated with UVB and treated with 100 mg/kg of L-glutathione by oral gavage. Treatment was given for 14 days, and UVB irradiation was given on days 9, 11, and 13. Oral L-glutathione significantly (P

Commercial sunscreens contain cosmetic preservatives which could exert phototoxic effect when exposed to sunlight. Natural sources such as resveratrol has gain attention in cosmetic world as it has higher antioxidant capacity than vitamin C and E. Resveratrol also possesses strong anti-inflammatory, anti-cancer and anti-aging properties. It also has proven to reduce epidermal hyperplasia and skin thickness. The aim of the study was to evaluate ameliorative effect of resveratrol in reducing epidermal hyperplasia of mouse skin exposed to UVB irradiation. Eighteen female BALB/c mice were randomly divided into 3 groups: control group (n=6), without UVB irradiation and resveratrol administration; UVB exposure group (n=6), irradiated with UVB dose of 250 mJ/cm2 for 3 minutes; and treatment group (n=6), irradiated with UVB and treated with 0.02 ml of 200 mg/kg of resveratrol by oral gavage. Treatment was given for 14 days and UVB exposure was given on day 9, 11, 13. On day 15, skin morphology was observed and skinfold thickness was measured to evaluate edema. The mice were then sacrificed to obtain dorsal part of skin for histopathological observation using Hematoxylin and Eosin (H&E) stain. Resveratrol reduced skin scaling and erythema in UVB induced mice. Skinfold thickness of resveratrol decreased significantly (p=0.001) as compared to UVB irradiated group. H&E staining showed that resveratrol group reduced leukocyte infiltration and epidermal hyperplasia as compared to UVB exposure group. Hence, oral resveratrol was able to reduce skin thickness and epidermal hyperplasia and it has the potential to be developed as a natural alternative for photoprotection.

Ultraviolet radiation (UVR) from sunlight is an environmental human carcinogen. Skin exposure to UVR would increase the oxidative stress, deoxyribonucleic acid (DNA) damage, melanogenesis and photocarcinogenesis. Therefore, development of photoprotective agent is necessary in order to reduce the cutaneous toxicity. The use natural active compounds like stilbenes and its derivatives have gained attention as photoprotection to skin due to its broad biological activities such as antioxidant, anti-inflammatory, anti melanogenesis and chemoprevention. This review article aims to analyse the existing literature on the photoprotective effect of stilbenes and its derivatives which include the resveratrol, pterostilbene, piceatannol and oxyresveratrol on in vitro and in vivo studies. This article describes the stilbenes and its derivatives protect and prevent UVR induced skin disorders via the reduction of oxidative stress, alleviation of DNA damage, inhibition of melanogenesis and anti photocarcinogenic effect.

Pesticides and chemical fertilizers are widely used in agriculture to increase crop productivity among farmers. However, exposure to pesticides will give potential risk to human health. The aim of this study was to analyze the frequency of micronucleus (MN) and binucleus (BNu) formation in buccal cells from farmers who were exposed to pesticides using the MN assay. Buccal swabs were collected from the farmers in Tanjung Karang (n = 32) and Kelantan (n = 43) using wooden tongue depressor. A structured questionnaire was used to obtain demographic data of the farmers. Cytogenetic analysis was carried out by Acridin Orange (AO) staining 0.0025% (w/v). The frequency of MN and BNu as the biomarkers for cytogenetic damage was observed by using a fluorescence microscope. Comparison of frequency of MN and BNu is conducted in two areas namely Tanjung Karang, Selangor and Kelantan because of the agricultural activity and the type of pesticides used are different. Results showed that the frequencies of both MN and BNu among farmers in Tanjung Karang were significantly higher (p 0.05) and the practices of PPE (Personal Protective Equipment) (p > 0.05). This may suggests that cytogenetic changes were not influenced by these factors. In addition, correlation study shows positive correlation between the frequency of MN with the pesticide exposure of farmers in Tanjung Karang (p > 0.05, r = 0.015) and Kelantan (p > 0.05, r = 0.0158). Besides, the frequency of BNu also has a positive correlation with the pesticide exposure among farmers in Tanjung Karang (p > 0.05, r = 0.036) and farmers in Kelantan (p > 0.05, r = 0.013). Hence, this present study demonstrated that exposure to pesticides increased the formation of MN and BNu among farmers and the prolonged use of pesticides may induce genotoxicity and DNA damage to human. DOI : http://dx.doi.org./10.17576/JSKM-2018-01

Drug Metabolizing Enzyme (DME) has been a target of natural chemopreventive agents to inhibit, retard and reverse the process of carcinogenesis. Pterostilbene, an analog to resveratrol has been reported to possess various pharmacological benefits including chemoprevention. In our study, benzo[a]pyrene-induced HT-29 colorectal cell line was used as the DME model. The activity of phase I enzyme CYP1A as determined by the 7-ethoxyresorufin O-deethylation (EROD) assay was found to be inhibited significantly by pterostilbene at 50 µM, 75 µM and 100 µM (p ≤ 0.01, p ≤ 0.05, p ≤ 0.01 respectively) compared to the benzo[a]pyrene treated group. Meanwhile, pterostilbene induced glutathione-S-transferase (GST) activity significantly (p ≤ 0.01) at 50 µM as compared to the untreated. In addition, However, the protein expression of CYP1A1 and GST in pterostilbene treated group was not significantly affected compared to untreated. On the other hand, pterostilbene at 25 and 75 µM were able to increase the protein expression of transcription factor Nrf2 significantly (p ≤ 0.01). Results indicated that pterostilbene could reduce metabolic activation of procarcinogens and increase the detoxification process which can be potentially developed as chemopreventive agent. DOI : http://dx.doi.org./10.17576/JSKM-2018-05

Canarium odontophyllum or locally known as Dabai in Sarawak is a fruit largely consumed by the locals. Based on previous studies, the plant possessed various biological activities, such as antimicrobial, antioxidant, antifungal and anticancer. Our aim was to investigate the mutagenicity and antimutagenicity of C. odontophyllum acetone leaves extracts by using the Ames test (Salmonella reverse mutagenicity assay).The Ames test also involved the pre-incubation method against Salmonella typhimurium TA98 and TA100 bacterial strains in the absence and presence of metabolic activator S9 system. C. odontophyllum crude acetone extracts were diluted with 10% DMSO to obtain three different concentrations of 3.125, 12.5 and 50 mg/ml. To determine the mutagenicity effects of the extracts, each concentration of the extract was evaluated based on the two-fold value of the number of revertant’s colony in negative control plate as the cut-of point. No mutagenic activity was observed for the frameshift mutation (TA98) and base-pair substitution mutation (TA100) in all concentrations of C. odontophyllum in the presence and absence of metabolic activator S9 system. Antimutagenicity test was carried out to determine the potential of C. odontophyllum extracts to inhibit the mutation induced by specific mutagens. The highest antimutagenic activity was seen in the presence of metabolic activator S9 system with inhibition percentage greater than 50% in both bacteria strains TA98 (62.38%) and TA100 (58.24%). In conclusion, C. odontophyllum acetone leaves extract was not mutagenic and had significant inhibitory effects on mutagenicity in both bacterial strains with and without the metabolic activator S9 system. Our results could contribute to the safe use of C. odontophyllum. In addition, based on the significant antimutagenic activity demonstrated by the C. odontophyllum acetone leaves extracts, the extract could also be developed as a chemopreventive agent.