Hazilawati Hamzah

Virgin microplastics cause toxicity and modulate the impacts of phenanthrene on biomarker responses in African catfish (Clarias gariepinus)

Despite the ubiquity of microplastics (MPs) in aquatic environments and their proven ability to carry a wide variety of chemicals, very little is known about the impacts of virgin or contaminant-loaded MPs on organisms. The primary aim of this study was to investigate the impacts of virgin or phenanthrene (Phe)-loaded low-density polyethylene (LDPE) fragments on a suite of biomarker responses in juvenile African catfish (Clarias gariepinus). Virgin LDPE (50 or 500µg/L) were preloaded with one of two nominal Phe concentrations (10 or 100µg/L) and were exposed to the fish for 96h. Our findings showed one or both Phe treatments significantly increased the degree of tissue change (DTC) in the liver while decreased the transcription levels of forkhead box L2 (foxl2) and tryptophan hydroxylase2 (tph2) in the brain of C. gariepinus. Exposure to either levels of virgin MPs increased the DTC in the liver and plasma albumin: globulin ratio while decreased the transcription levels of tph2. Moreover, MPs modulated (interacted with) the impact of Phe on the DTC in the gill, plasma concentrations of cholesterol, high-density lipoprotein (HDL), total protein (TP), albumin, and globulin, and the transcription levels of fushi tarazu-factor 1 (ftz-f1), gonadotropin-releasing hormone (GnRH), 11 β-hydroxysteroid dehydrogenase type 2 (11β-hsd2), and liver glycogen stores. Results of this study highlight the ability of virgin LDPE fragments to cause toxicity and to modulate the adverse impacts of Phe in C. gariepinus. Due to the wide distribution of MPs and other classes of contaminants in aquatic environments, further studies are urgently needed to elucidate the toxicity of virgin or contaminant-loaded MPs on organisms.

Dietary cocoa protects against colitis‐associated cancer by activating the Nrf2/Keap1 pathway

Colorectal cancer (CRC) is the third most common malignancy in males and the second most common cancer worldwide. Chronic colonic inflammation is a known risk factor for CRC. Cocoa contains many polyphenolic compounds that have beneficial effects in humans. The objective of this study is to explore the antioxidant properties of cocoa in the mouse model of azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colitis-associated cancer, focusing on the activation of Nrf2 signaling. Mice were treated with AOM/DSS and randomized to receive either a control diet or a 5 and 10% cocoa diet during the study period. On day 62 of the experiment, the entire colon was processed for biochemical and histopathological examination and further evaluations. Increased levels of malondialdehyde (MDA) were observed in AOM/DSS-induced mice; however, subsequent administration of cocoa decreased the MDA. Enzymatic and nonenzymatic antioxidants, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, were decreased in the AOM/DSS mice. Cocoa treatment increases the activities/levels of enzymatic and nonenzymatic antioxidants. Inflammatory mediators, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, were elevated during AOM/DSS-induction, and treatment with 5 and 10% cocoa effectively decreases the expression of iNOS and COX-2. The NF-E2-related factor 2 and its downstream targets, such as NQO1 and UDP-GT, were increased by cocoa treatment. The results of our study suggest that cocoa may merit further clinical investigation as a chemopreventive agent that helps prevent CAC.

Antiviral Activity of Resveratrol against Human and Animal Viruses.

Resveratrol is a potent polyphenolic compound that is being extensively studied in the amelioration of viral infections both in vitro and in vivo. Its antioxidant effect is mainly elicited through inhibition of important gene pathways like the NF-κβ pathway, while its antiviral effects are associated with inhibitions of viral replication, protein synthesis, gene expression, and nucleic acid synthesis. Although the beneficial roles of resveratrol in several viral diseases have been well documented, a few adverse effects have been reported as well. This review highlights the antiviral mechanisms of resveratrol in human and animal viral infections and how some of these effects are associated with the antioxidant properties of the compound.

Histopathologic Changes in Liver and Kidney Tissues from Male Sprague Dawley Rats Treated with Rhaphidophora Decursiva (Roxb.) Schott Extract

Rhaphidophora decursiva (Roxb.) Schott is commonly used to treat colon cancer among Chinese community in Malaysia. This study aims to evaluate histopathologic changes in liver and kidney tissues after treated with R. decursiva extract in male Sprague Dawley rats. The rats were divided into 4 groups consisting of 6 rats per group for each acute, subacute and subchronic toxicity evaluations, with a total of 72 rats. All control groups received distilled water (vehicle). For subacute toxicity, the 3 treatment groups received a daily oral dose of the plant extract at 70, 140 or 210 mg/kg for 28 days. As no lethality was observed in subacute toxicity study, similar doses were used for the 3 treatment groups in 90-day subchronic toxicity. Histological examination of liver revealed some abnormal but not significant morphology characteristics. For acute toxicity, liver tissues in group treated with 2100 and 3500 mg/ kg extracts showed presence of activated kupffer cells, sinusoidal dilatation and cytoplasmic vacuolation, same as group treated with 140 and 210 mg/kg extracts for both subacute and subchronic toxicity. However, group treated with 140 mg/kg extract in subchronic toxicity just showed the presence of cytoplasmic vacuolation. Similarly, no significant abnormal histopathological changes were observed in kidneys tissue for all toxicity studies. The presence of granular cast were noticed in group treated with 2100 and 3500 mg/kg extracts for acute toxicity, however, cellular and protein cast only occurred in group treated with 3500 mg/kg extracts. For subacute and subchronic toxicity, granular cast can be observed in group treated with 210 mg/kg extract. Also, cellular can be seen in group treated with 210 mg/kg extract for subacute toxicity. In conclusion, the treatment of R. decursiva extracts did not show any significant toxicological changes as observed by histopathological examination in the kidney and liver tissues for all toxicity studies.

Effect of virgin avocado oil on diet-induced hypercholesterolemia in rats via 1H NMR-based metabolomics approach: Hypocholesterolemic effect of virgin avocado oil

Hypercholesterolemia is a major risk factor for the initiation and development of nonalcoholic fatty liver disease and atherosclerosis. The present study evaluated the hypocholesterolemic effect of virgin avocado oil (VAO) using urinary metabolomic method. Male Sprague–Dawley rats were fed high‐cholesterol diet for four weeks to induce hypercholesterolemia. After confirming the establishment of hypercholesterolemia model, the VAO (450 and 900 mg·kg−1·day−1) and simvastatin (10 mg·kg−1·day−1) were given orally while maintaining the high‐cholesterol diet for another four weeks. Assessment of urinary metabolomics using NMR revealed that VAO treatment could partially recover the metabolism dysfunction induced by hypercholesterolemia mainly via lipid, energy, amino acid, and gut microbiota metabolism.

Blood Profiles and Histopathological Changes of Liver and Kidney Tissues fromMale Sprague Dawley Rats Treated with Ethanol Extracts of Clinacanthusnutans Leaf

Background: Clinacanthus nutans (C. nutans) or commonly known as ‘Sabah snake grass’ or ‘Belalai Gajah’ is a widely known herb used to treat Herpes simplex virus (HPV), skin rashes and snake bite. Objective: This study aim is to evaluate the toxicity of ethanol extract of C. nutans leaf extract on 90-day sub chronic toxicity study in male Sprague Dawley rats. Method: A total of 40, 6-week male Sprague Dawley rats were divided into 5 groups (n=8) namely control, vehicle (10% DMSO), and 3 treatment groups which received a daily oral dose of C. nutans leaf extract at 75 (low dose), 125 (medium dose), and 250 (high dose) mg/kg for 90 days via oral gavage. Blood sample were collected at the end of the experiment for evaluation of haematology and serum biochemistry. Selected organs including liver and kidneys were collected for histopathological examination. The toxicity were evaluated by observing and evaluating the changes of body weight, haematology and serum biochemistry parameters and histopathology changes of liver and kidney tissues. Results: There was no mortality sign of sub chronic toxicity observed during the observation period. Body weight, haematology parameters and organ relative weight showed no significant difference in control and treatment groups meanwhile in serum biochemistry parameters, observed a significant difference (P<0.05) in level of LDH and creatinine kinase in high dose group showed significant lower(P<0.05) compared to control. Nevertheless the levels of LDH and creatinine kinase were still in normal range. Significant abnormal histopathological changes (P<0.05) such as centrilobular sinusoid dilatation/centrilobular necrosis, hydropic degeneration/cytoplasmic vacuolation and inflammation were observed in liver tissues in medium and high dose groups. Kidney tissue showed a significant abnormal histopathology changes (P<0.05) such as granular cast and cellular cast were observed in medium and high dose group. Conclusion: It is concluded that 125-250 mg/kg ethanol extract of C. nutans leaves induce hepatotoxicity and renal toxicity.