M. Musalmah

Comparative effects of palm vitamin E and α-tocopherol on healing and wound tissue antioxidant enzyme levels in diabetic rats

The effect of supplementing 200 mg/kg body weight palm vitamin E (PVE) and 200 mg/kg body weight α-tocopherol (α-loc) on the healing of wounds in streptozotocin-induced diabetic rats was evaluated. The antioxidant potencies of these two preparations of vitamin E were also evaluated by determining the antioxidant enzyme activities, namely, glutathione peroxidase (GPx) and superoxide dismutase (SOD), and malondialdehyde (MDA) levels in the healing of dermal wounds. Healing was evaluated by measuring wound contractions and protein contents in the healing wounds. Cellular redistribution and collagen deposition were assessed morphologically using cross-sections of paraffin-embedded day-10 wounds stained according to the Van Gieson method. GPx and SOD activities as well as MDA levels were determined in homogenates of day-10 dermal wounds. Results showed that PVE had a greater potency to enhance wound repair and induce the increase in free radical-scavenging enzyme activities than α-Toc. Both PVE and α-Toc, however, were potent antioxidants and significantly reduced the lipid peroxidation levels in the wounds as measured by the reduction in MDA levels.

Modulation of oxidative stress by Chlorella vulgaris in streptozotocin (STZ) induced diabetic Sprague-Dawley rats

PURPOSE Chlorella vulgaris (CV), a fresh water alga has been reported to have hypoglycemic effects. However, antioxidant and anti-inflammatory effects of CV in diabetic animals have not been investigated to date. The aim of the present study was to investigate the role of CV in inflammation and oxidative damage in STZ-induced diabetic rats. MATERIALS AND METHODS Male Sprague-Dawley rats (300 - 400g) were divided into 4 groups: control, CV, STZ-induced diabetic rats, and STZ rats treated with CV (150mg/kg body wt). Blood samples were drawn from orbital sinus at 1 and 4 weeks for determination of oxidative cellular damage (DNA damage and lipid peroxidation [malondialdehyde, MDA]), inflammation (tumour necrosis factor alpha, TNF-α) and antioxidant status (catalase, CAT, and superoxide dismutase, SOD). RESULTS CV did not have any effects on glucose levels in diabetic rats, over the 4 weeks of treatment. However, it reduced significantly DNA damage and blood MDA levels in STZ-induced diabetic rats compared to the control group. Plasma levels of TNF-α however did not show any significant changes in STZ-induced diabetic rats fed with CV. Antioxidant enzyme SOD showed no significant changes in all groups but CAT activity was reduced in STZ-induced diabetic rats compared to the control. CONCLUSIONS CV did not have hypoglycaemic effect but it has a protective role in STZ-induced diabetic rats by reducing oxidative DNA damage, and lipid peroxidation.

Does long term supplementation of Vitamin E cause detrimental effects on the central nervous system? Morphological and histological study in experimental male Wistar rats

AIM Aging is attributed to neuronal loss associated with increased oxidative stress. Vitamin E, and in particular, tocotrienol are potent antioxidants, which have been shown to be neuroprotective. The main aim of the present study was to observe the effect of long term intake of vitamin E in the form of tocotrienol rich fraction (TRF) and refined, bleached, deodorized palm olein (RBDPO) on the brain of experimental rats. MATERIALS AND METHODS Thirty male Wistar rats aged 3 months were either supplemented with TRF (dose of 200 mg/kg body weight), RBDPO (dose of 1 ml/kg body weight) or distilled water, continuously for 8 months. The animals were then examined in vivo for clinical magnetic resonance imaging (MRI) studies before being sacrificed. The brain was extracted, measured and studied for histological changes. RESULTS The magnetic resonance imaging (MRI) scan of the lateral ventricle, cortical thickness of cingulate gyrus and hippocampus size did not show any significant changes in all three groups. The brain weight, length and width as well as histological sections of the brain showed no significant changes between the groups. CONCLUSION It is thereby concluded that chronic consumption of vitamin E was not detrimental to the central nervous system.