HYPOTENSIVE ACTIVITY OF THYMOQUINONE IN NORMOTENSIVE RATS AND ITS RECEPTOR MECHANISMS

Objective: The objectives of the current study were to confirm the blood pressure lowering effect of thymoquinone (TQ) and to investigate its mechanism through muscarinic and β-adrenergic receptors.Methods: Mean arterial blood pressure (MAP) was recorded using the non-invasive blood pressure tail-cuff technique. A dose-response relationship was obtained after using 3 TQ doses (2.5, 5 and 10 mg/kg) intraperitoneally to 3 different groups (n =5) of adult rats under pentobarbital anesthesia. MAP was then measured for another 2 animal groups pretreated either with atropine (P-at) or propranolol (P-pro) followed by 10 mg/kg TQ.Results: TQ produced a significant dose-dependent blood pressure and heart rate lowering effect. TQ-induced MAP reduction was significantly less pronounced in P-at (12±2.8 mmHg) than non-pretreated group (29±3.2 mmHg) with P<0.01. Conversely, TQ-induced MAP reduction in P-pro (28±3.4 mmHg) did not demonstrate a significant difference from the non-pretreated group (29±3.2 mmHg) with P>0.05.Conclusion: This study confirms the dose-related hypotensive effect of TQ and provides an evidence for the traditional use of Nigella sativa for the treatment of hypertension. The mechanism of TQ-induced hypotension involves at least in part activation of vascular muscarinic receptors, but not β-adrenergic receptors

Mnemonic and histopathological assessment of the neuroprotective effects of Murraya koenigii leaves extract in rats with partial global cerebral ischaemia

Preclinical studies have reported that Murraya koenigii leaves (MKL) could enhance memory. MKL is also known for its antioxidant activity. The current study was to assess the possible neuroprotective potential of MKL methanolic extract in a two vessel occlusion (2VO) rat model of partial global cerebral ischaemia. Methods: Rats were divided into memory and learning groups. Each group was subdivided into sham control, untreated 2VO and MKL-treated 2VO subgroups. The Morris water maze test was implemented to assess the rats’ cognitive function postoperatively. Brain samples were histopathologically examined for viable neurons within the CA1 hippocampal region. Results: Water maze test findings showed that MKL positively improved memory and learning impairments. However, this improvement in memory test for the treated group was still significantly inferior to that of the healthy control group. Additionally, MKL treated group exhibited insignificant difference in the number of viable hippocampal CA1 pyramidal neurons from that of the untreated 2VO group, whereas both MKL treated and untreated 2VO groups showed significantly less viable neurons when compared with the control group. Conclusion: MKL extract modestly improved memory without providing substantial neuroprotective action to the hippocampal neurons in rats with chronic partial global cerebral ischaemia

Chronic LD50 vs safest dose for the methanolic extract of curry leaves (Murraya koenigii) cultivated in Malaysia

Curry leaf viz. Murraya koenigiil eaves (MKL) is an ancient Ayurvedic medicinal plant that has recently been described as possessing robust anti-inflammatory and antioxidant activities. The current study was conducted to determine the long-term LD50 of the methanolic extract of MKL during daily oral administration. Five groups of Sprague Dawley rats were recruited into the study. Each group comprised of six rats including the control group (1). The oral MKL doses used for groups (2) to (5) were 50, 100, 200 and 400 mg/kg/day, respectively for a duration of ten weeks. The daily measured toxicity parameters were food and water consumption, body weight, general activity in forced swimming test and the cumulative mortalities. Group (5) showed 100% mortality within the first month of the study. Group (4) showed 50% mortality with signs of toxicity for the other 3 animals. Group (3) showed no mortalities but signs of toxicity for one animal were observed. No mortalities or toxicity signs were observed for any of group (2) animals. It can be concluded that the chronic LD50 for Malaysian cultivated MKL is 200 mg/kg/day, and the safest dose of MKL methanolic extract that can be implemented for long-term studies should not exceed 50 mg/kg/day

Role of Drug-coated Balloons in Small-vessel Coronary Artery Disease

Percutaneous coronary intervention of small-vessel coronary artery disease (SVD) remains challenging due to difficulties with device delivery and high restenosis rate, even with the use of newer-generation drug-eluting stents. Drug-coated balloons represent an attractive emerging percutaneous coronary intervention option in patients with SVD. Potential advantages of drug-coated balloons in SVD include enhanced deliverability because of their small profile, avoidance of foreign-body implantation, and shorter duration of dual antiplatelet therapy

Verbal processes in the Covid-19 news discourses: An analysis of ‘aswaqpress.com’ coverage on Malaysia: Proses verbal dalam wacana berita Covid-19: Analisis portal ‘aswaqpress.com’ berkaitan Malaysia

December 2019 marked the emergence of a deadly virus known as Covid-19. Since then, we have been battling the virus, which has infected more than 250 million people and killed 4.5 million globally. The pandemic has become the headline of almost every media outlet, local and international news agency. Hence, this article aims to examine the Arabic online news discourse of the event by focusing on the verbal processes strategically utilised in reporting the pandemic in Malaysia. This study's data consists of Modern Standard Arabic online news published by Aswaq (aswaqpress.com) news portal between January and July 2021. Aswaq provides Arabic news and information on Malaysia to the Arab world. Hence, the information provided by the portal is vital in portraying Malaysia to Arab audiences, particularly in framing the way Malaysia deals with the Covid-19. The study employs corpus linguistics analytical tools using corpus software AntConc 3.5.8 (2019). Then, the quantitative result will be analysed using a qualitative approach based on the textual-oriented Critical Discourse Analysis (CDA) of Fairclough (1992). It is shown that Aswaq has strategically utilised various verbal processes to report on the word said and articulated around the pandemic. The diversity of verbal processes usage indicates different connotations that hint at different strategic approaches in reporting the news. Hence, it may lead to uncovering the outlet stance of the event. Finally, the study will present suggestions for other related studies in the future

Protective effect of treatment with black cumin oil on spatial cognitive functions of rats that suffered global cerebrovascular hypoperfusion

The fixed oil of black cumin seeds, Nigella sativa L. (NSO), has shown considerable antioxidant and anti-inflammatory activities. Chronic cerebral hypoperfusion has been linked to neurodegenerative disorders including Alzheimer’s disease (AD)and its subsequent cognitive impairment in which oxidative stress and neuroinflammation are the principal culprits. Cerebrovascular hypoperfusion was experimentally achieved by bilateral common carotid arteries occlusion (2VO) in rats. Morris water maze (MWM) test was employed to assess the effects of NSO on spatial cognitive function before and after 2VO intervention. Rats were divided into long-term memory (LTM) and short-term memory (STM) groups, each was further subdivided into 3 subgroups: sham control, untreated 2VO and NSO treated 2VO group. All subgroups were tested with MWM at the tenth postoperative week. Working memory test results for both sham control and NSO treated groups showed significantly lower escape latency time and total distance travelled than untreated 2VO group. Similarly, LTM and STM MWM tests for sham control and NSO treated groups revealed significantly better maze test performance as compared to untreated 2VO group. Sham control and NSO treated 2VO groups demonstrated superior probe memory test performance as compared to untreated 2VO group. The fixed oil of Nigella sativa seeds has demonstrated noticeable spatial cognitive preservation in rats challenged with chronic cerebral hypoperfusion which indicates a promising prospective neuroprotective effect

Development of 4D printed PLA actuators

Four-dimensional (4D) printing is currently in the early stages of development and is deficient in offering designers and researchers the freedom to develop 4D printable structures. The first step to ensuring the use of such technology by researchers requires additional testing and simulation for 4D printing. It also requires an assessment of the shape memory effect in the materials that are being printed. This paper tests 4D printed actuators that possess an induced strain following printing. The induced strain is achieved during the printing process following fused deposition modelling. The induced strain permits alteration of the shape after material stimulation following printing, which eliminates the requirement for a separate programming step where alterations are required for force and stimulation to achieve the print shape temporarily. The proposed approach consists of two actuators and a drug delivery application via an open-sided box reservoir. The process of printing and shape change of polylactic acid is completed and the level of bending of actuators is then measured. The printing of designs is done at 10 mm/s for passive layers and 60 mm/s speed for active layers. The heating of the printed samples is done, and the bending angle is measured for the replication process through simulation. Finite element analysis (FEA) of the actuators is done to replicate the strain-induced through the use of materials demonstrating thermal expansion. The FEA parameters are utilized to develop intricate structures and simulate the change of the shape. The deformation values achieved by Designs 1 and 2 in the z-axis are 7.81 mm and 6.06 mm, respectively, and 4.84 mm for the reservoir

Receptor mechanisms of thymoquinone-induced hypotension in normotensive rats

Nigella sativa (NS), more commonly known as ‘’Habbattu Sauda’’, is a plant that is traditionally used to control hypertension. Evidence based studies revealed that NS exerts diuretic and blood pressure lowering effect in spontaneously hypertensive rat. While the volatile oil of NS acts centrally by indirect and direct mechanisms to induce cardio-depressant effect in urethane-anaesthetized rats, Thymoquinone (TQ) represents the main active constituent in the volatile oil, which could be the principal substance of the direct mechanism. Objective was to evaluate the hypotensive effect of TQ and its dose-response relationship in normotensive adult rats using the non-invasive tail-cuff technique. To investigate TQ mechanism of action through muscarinic and β adrenergic receptors. Three doses of TQ (2.5, 5 and 10 mg\kg) were used for assessing TQ hypotensive effect in 3 groups of rats (n=5) under sodium pentobarbital anesthesia. TQ was administered intraperitoneally, and mean arterial blood pressure (MAP) was obtained from recording systolic and diastolic pressure readings using the non-invasive tail-cuff technique and the dose-response relationship was obtained. MAP was then measured for other 2 animal groups pretreated either with atropine (P-at) or propranolol (P-pro) followed by 10 mg/kg TQ. This study confirms the dose-related hypotensive effect of TQ. The study showed that the mechanism of TQ-induced hypotension involves at least stimulation of vascular muscarinic receptors, but not β-adrenergic receptors. This study provides an evidence for the traditional use of Nigella sativa for treatment of hypertension

Antihypertensive and antihyperlipidemic activities of thymoquinone in l-name hypertensive rats

Objective: of this study was to evaluate the antihypertensive potential of Thymoquinone TQ and to investigate the underlying mechanism of action. Method: Hypertension was induced in in Sprague Dawley rats (n = 40) by administration of L-Nitro-Arginine Methyl Ester (L-NAME) in drinking water for 4 weeks. At the end of induction period, rats were divided into 6 groups (n = 8); TQ2.5+L-NAME, TQ5+L-NAME, TQ10+L-NAME, captopril+L-NAME, L-NAME only and control. Mean arterial pressure (MAP) and hear rate (HR) were recorded by the non-invasive tail cuff technique weekly for 28 days. Then animals were sacrificed and blood was collected for determination of ACE activity and aldosterone concentration using ELISA. Lipid profile (total cholesterol, LDL, HDL, TRG) was assayed twice; at the end of induction period and at the end of treatment period. Results: TQ reversed the established hypertension in TQ5 and TQ10 groups, and prevented further increase in MAP in TQ2.5 group. Unlike captopril treated group, TQ antihypertensive activity was associated with an increase in serum aldosterone concentration and ACE activity. TQ treatment at the high dose significantly lowered total cholesterol and LDL levels in comparison with the healthy control group at the end of the 4th week of treatment. Conclusion: This study confirms the antihypertensive effect of TQ which did not take place through inhibition of ACE, but probably through blocking angiotensin II receptors

The effect of flaxseed ethanolic extract on the structure of the kidney and the endocrine pancreas in streptozotocin induced diabetic rats

Background: The present investigation has been designed to study the possible protective effect of flaxseed extract on the structures of the endocrine pancreas and kidneys of streptozotocin (STZ) induced diabetic rats for 30 days. Methods: Forty male Sprague-Dawley rats were randomized into five groups (n=8). Normal control group (NC); received distilled water orally, normal flaxseed group (NF); treated orally with (400 mg/kg) extract of flaxseed, diabetic control group (DC); treated with single intraperitoneal dose of STZ (60 mg/kg), diabetic flaxseed group (DF); diabetic rats treated with extract of flaxseed (400 mg/kg), diabetic glibenclamide group (DG); diabetic rats treated with (0.6 mg/kg) glibenclamide. Results: Histological observation of sections in pancreas in DC group revealed shrunken islets of Langerhans with degenerated and degranulated β-cells, vacuolations and congested capillaries while sections of kidneys showed shrinkage of some glomeruli and degeneration of others with wide urinary space and hydropic degeneration in some tubular epithelial cells, dilated tubules and cell debris scattered in tubular lumina. These pathological changes were ameliorated in the flaxseed extract and glibenclamide treated rats. Conclusions: It is concluded that flaxseed extract may represent a good alternative treatment for management of diabetes and its related complications such as diabetic nephropathy