Mechanisms of the antihypertensive effects of Nigella sativa oil in L-NAME-induced hypertensive rats

OBJECTIVES

This study was conducted to determine whether the blood pressure-lowering effect of Nigella sativa might be mediated by its effects on nitric oxide, angiotensin-converting enzyme, heme oxygenase and oxidative stress markers.

METHODS

Twenty-four adult male Sprague-Dawley rats were divided equally into 4 groups. One group served as the control (group 1), whereas the other three groups (groups 2-4) were administered L-NAME (25 mg/kg, intraperitoneally). Groups 3 and 4 were given oral nicardipine daily at a dose of 3 mg/kg and Nigella sativa oil at a dose of 2.5 mg/kg for 8 weeks, respectively, concomitantly with L-NAME administration.

RESULTS

Nigella sativa oil prevented the increase in systolic blood pressure in the L-NAME-treated rats. The blood pressure reduction was associated with a reduction in cardiac lipid peroxidation product, NADPH oxidase, angiotensin-converting enzyme activity and plasma nitric oxide, as well as with an increase in heme oxygenase-1 activity in the heart. The effects of Nigella sativa on blood pressure, lipid peroxidation product, nicotinamide adenine dinucleotide phosphate oxidase and angiotensin-converting enzyme were similar to those of nicardipine. In contrast, L-NAME had opposite effects on lipid peroxidation, angiotensin-converting enzyme and NO.

CONCLUSION

The antihypertensive effect of Nigella sativa oil appears to be mediated by a reduction in cardiac oxidative stress and angiotensin-converting enzyme activity, an increase in cardiac heme oxygenase-1 activity and a prevention of plasma nitric oxide loss. Thus, Nigella sativa oil might be beneficial for controlling hypertension.

Cardioprotective effect of virgin coconut oil in heated palm oil diet-induced hypertensive rats

CONTEXT

Virgin coconut oil (VCO) contains high antioxidant activity which may have protective effects on the heart in hypertensive rats.

OBJECTIVES

The study investigated the effects of VCO on blood pressure and cardiac tissue by measuring angiotensin-converting enzyme (ACE) activity and its histomorphometry in rats fed with a heated palm oil (HPO) diet.

MATERIALS AND METHODS

Thirty-two male Sprague-Dawley rats were randomly divided into four groups: (i) control, (ii) orally given VCO (1.42 ml/kg), (iii) fed with a HPO (15%) diet, and (iv) fed with a HPO diet and supplemented with VCO (1.42 ml/kg, po) (HPO+VCO) for 16 weeks. Blood pressure was measured monthly. After 16 weeks, rat hearts were dissected for lipid peroxidation (TBARS) and ACE activity measurement and histomorphometric study.

RESULTS

Systolic blood pressure was significantly increased in the HPO group compared with the control starting at week eight (112.91 ± 1.32 versus 98.08 ± 3.61 mmHg, p < 0.05) which was prevented by VCO supplementation (91.73 ± 3.42 mmHg). The consumption of HPO increased TBARS and ACE activity in heart, which were inhibited by VCO supplementation. The increases in the myofiber width and area as well as nuclear size reduction in the HPO group were significantly prevented by VCO supplementation.

CONCLUSION

These results suggested that VCO supplementation possesses a cardioprotective effect by preventing the increase in blood pressure via an antioxidant mechanism and remodeling in rats fed repeatedly with a HPO diet.

Nitrate occurrence in the groundwater of the Loukkos perimeter

This study assesses the occurrence of nitrate in the groundwater beneath the R'mel area of the Loukkos perimeter (north-west Morocco), which covers an approximate area of 2,560 km2 and is located between the towns of Ksar el Kebir and Larache. It also borders the Atlantic Ocean. Groundwater supplies are the principal source of drinking water in this region and there is no public drinking water network in the rural area. This perimeter has a population of about 500,000 inhabitants of which the rural population represents 60%, many of whom have depended on and used the water from the aquifers for many years. The inhabitants and farmers depend on the groundwater supplies for drinking water, crop irrigation and other uses. The plain provides the ideal conditions for agriculture and the use of chemical fertilisers has been increasing. In this study, 53 water samples were collected from wells and springs. Each well or spring was sampled once or twice during 1998-2000. Nitrate concentrations ranged from extremely low up to 144 mg L(-1). Nitrate concentrations exceeded the maximum contaminant level (MCL) of 50 mg L(-1) in 12 of the 53 groundwater samples (23%), whereas 31 of the 53 samples (58%) had nitrate concentrations of less than 25 mg L(-1).

Analysis of examinations in curriculum review

This paper describes the analysis of the written professional examinations administered at the Medical School, Universiti Kebangsaan Malaysia (UKM), during the academic year 1979-80. It is a product of a collaborative activity involving medical teachers and two short-term consultants of the World Health Organization. The examination papers were analysed in order to identify content areas disproportionately emphasized in the examinations; to determine the quality and appropriateness of the examination items used; and to review the extent of continuity and integration across departments and courses. This paper is intended to introduce an approach to curriculum review which is based on analysis of the examination system. The procedures and sample outcomes are described and the implications for curriculum development and evaluation are discussed.

Ocular involvement in acute lymphoblastic leukaemia

A six-year-old boy, a known case of acute lymphoblastic leukaemia (ALL) on remission since 1991 presented with leukocoria and poor vision of the left eye for two days' duration. Examination revealed endophthalmitis in the left eye with raised intraocular pressure. Anterior chamber paracentesis with vitreous biopsy confirmed a diagnosis of ocular involvement. Further investigation revealed that he also had bone marrow and central nervous system relapse. Clinical manifestation and treatment modalities of ocular involvement in leukaemia are discussed.

Deep-fried keropok lekors Increase Oxidative Instability in Cooking Oils

BACKGROUND

This study was performed to compare the oxidative quality of repeatedly heated palm and soybean oils, which were used to fry keropok lekors and potato chips.

METHODS

A kilogramme of keropok lekors or potato chips was fried in 2.5 L of palm or soybean oil at 180 °C for 10 minutes. The frying process was repeated once and four times to obtain twice-heated and five-times-heated oils. The peroxide value and fatty acid composition of the oils were measured.

RESULTS

Frequent heating significantly increased the peroxide values in both oils, with the five-times-heated oils having the highest peroxide values [five-times-heated palm: 14.26 ± 0.41 and 11.29 ± 0.58 meq/kg vs fresh: 2.13 ± 0.00, F (3,12) = 346.80, P < 0.001; five-times-heated soybean: 16.95 ± 0.39 and 12.90 ± 0.21 meq/kg vs fresh: 2.53 ± 0.00 oils, F (3,12) = 1755, P < 0.001, when used to fry keropok lekors and potato chips, respectively]. Overall, both oils showed significantly higher peroxide values when keropok lekors were fried in them compared with when potato chips were fried. In general, the heated soybean oil had significantly higher peroxide values than the heated palm oil. Fatty acid composition in the oils remained mostly unaltered by the heating frequency.

CONCLUSION

keropok lekors, when used as the frying material, increased the peroxide values of the palm and soybean oils. Fatty acid composition was not much affected by the frequency of frying or the fried item used.

Level of knowledge, attitude and practice of night market food outlet operators in Kuala Lumpur regarding the usage of repeatedly heated cooking oil

Consumption of repeatedly heated oil can be detrimental to health. The objective of this study was to determine the level of knowledge, attitude and practice of night market food outlet operators in Kuala Lumpur regarding the usage of repeatedly heated cooking oil. The quality of cooking oil was also investigated. A cross-sectional study involving pretested questionnaire was undertaken in April 2009. The questionnaire was designed as a tool to collect data from the respondents (n=100) by face-to-face interview. The results showed that majority of respondents had only moderate (53.0%) or low (18.0%) level of knowledge regarding this issue. Most respondents (67.0%) agreed that it is not a good practice. The majority (69.0%) agreed that the usage of repeatedly heated cooking oil is detrimental to health. Despite that, most respondents (63.0%) admitted that they had used cooking oil repeatedly. Most (62.0%) of the cooking oil samples taken from the night market food outlets were considered fit for human consumption. In conclusion, the level of knowledge of night market food outlet operators in Kuala Lumpur regarding this issue needs to be improved in order to ensure the safety of fried food purchased from such establishments.

Evaluation of a bilingual questionnaire-based assessment on hearing in children with speech delay

INTRODUCTION

To correlate the score obtained using a bilingual (Malay and English) 14 points questionnaire in the detection of hearing loss at the University of Malaya, Medical Centre (UMMC), Kuala Lumpur, Malaysia over a 9 month period.

METHODS

This is a prospective instrument correlation study done on 93 children aged 1-4 years of age with speech and language delay for at least 3 months. Hearing status was confirmed using otoacoustic emissions, pure tone audiometry and brainstem evoked response (BSER). Hearing status was then compared to the 14-point questionnaire final scores and is statistically correlated.

RESULTS

There were 26 patients, 15 males (58%) and 11(42%) females who were diagnosed to have hearing loss. The average age of presentation was 2.49 and conductive hearing loss accounted for about 74% of cases of hearing loss. The mean questionnaire score obtained through our patients was 3.83±1.987. Discriminant analysis suggests that a questionnaire score of above 4 was indicative that the child was suffering from hearing loss.

CONCLUSION

Our study suggests that the low-cost bilingual (Malay and English) questionnaire can be used to detect hearing loss in the Malaysian population and could potentially be useful in rural health centres to help detect hearing loss and to determine the urgency of referral to a tertiary health centre.