Muhammad Rashid Khan

Bio: Muhammad Rashid Khan is an academic researcher from Quaid-i-Azam University. The author has contributed to research in topics: Antioxidant & Lipid peroxidation. The author has an hindex of 44, co-authored 191 publications receiving 6388 citations. Previous affiliations of Muhammad Rashid Khan include Cornell University & Jilin University.

Antioxidant activity, total phenolic and total flavonoid contents of whole plant extracts Torilis leptophylla L

Abstract: The aim of this study was to screen various solvent extracts of whole plant of Torilis leptophylla to display potent antioxidant activity in vitro and in vivo, total phenolic and flavonoid contents in order to find possible sources for future novel antioxidants in food and pharmaceutical formulations. A detailed study was performed on the antioxidant activity of the methanol extract of whole plant of Torilis leptophylla (TLM) and its derived fractions {n-hexane (TLH), chloroform (TLC) ethyl acetate (TLE) n-butanol (TLB) and residual aqueous fraction (TLA)} by in vitro chemical analyses and carbon tetrachloride (CCl4) induced hepatic injuries (lipid peroxidation and glutathione contents) in male Sprague-Dawley rat. The total yield, total phenolic (TPC) and total flavonoid contents (TFC) of all the fractions were also determined. TLM was also subjected to preliminary phytochemical screening test for various constituents. The total phenolic contents (TPC) (121.9±3.1 mg GAE/g extract) of TLM while total flavonoid contents (TFC) of TLE (60.9 ±2.2 mg RTE/g extract) were found significantly higher as compared to other solvent fractions. Phytochemical screening of TLM revealed the presence of alkaloids, anthraquinones, cardiac glycosides, coumarins, flavonoids, saponins, phlobatannins, tannins and terpenoids. The EC50 values based on the DPPH (41.0±1 μg/ml), ABTS (10.0±0.9 μg/ml) and phosphomolybdate (10.7±2 μg/ml) for TLB, hydroxyl radicals (8.0±1 μg/ml) for TLC, superoxide radicals (57.0±0.3 μg/ml) for TLM and hydrogen peroxide radicals (68.0±2 μg/ml) for TLE were generally lower showing potential antioxidant properties. A significant but marginal positive correlation was found between TPC and EC50 values for DPPH, hydroxyl, phosphomolybdate and ABTS, whereas another weak and positive correlation was determined between TFC and EC50 values for superoxide anion and hydroxyl radicals. Results of in vivo experiment revealed that administration of CCl4 caused a significant increase in lipid peroxidation (TBARS) while decrease in GSH contents of liver. In contrast, TLM (200 mg/kg bw) and silymarin (50 mg/kg bw) co-treatment effectively prevented these alterations and maintained the antioxidant status. Data from present results revealed that Torilis leptophylla act as an antioxidant agent due to its free radical scavenging and cytoprotective activity.

Alterations of the Gut Microbiome in Hypertension.

Abstract: Introduction: Human gut microbiota is believed to be directly or indirectly involved in cardiovascular diseases and hypertension. However, the identification and functional status of the hypertension-related gut microbe(s) have not yet been surveyed in a comprehensive manner. Methods: Here we characterized the gut microbiome in hypertension status by comparing fecal samples of 60 patients with primary hypertension and 60 gender-, age-, and body weight-matched healthy controls based on whole-metagenome shotgun sequencing. Results: Hypertension implicated a remarkable gut dysbiosis with significant reduction in within-sample diversity and shift in microbial composition. Metagenome-wide association study (MGWAS) revealed 53,953 microbial genes that differ in distribution between the patients and healthy controls (false discovery rate, 0.05) and can be grouped into 68 clusters representing bacterial species. Opportunistic pathogenic taxa, such as Klebsiella spp., Streptococcus spp. and Parabacteroides merdae were frequently distributed in hypertensive gut microbiome, whereas the short-chain fatty acid producer, such as Roseburia spp. and Faecalibacterium prausnitzii, were higher in controls. The number of hypertension-associated species also showed stronger correlation to the severity of disease. Functionally, the hypertensive gut microbiome exhibited higher membrane transport, lipopolysaccharide biosynthesis and steroid degradation, while in controls the metabolism of amino acid, cofactors and vitamins was found to be higher. We further provided the microbial markers for disease discrimination and achieved an area under the receiver operator characteristic curve (AUC) of 0.78, demonstrating the potential of gut microbiota in prediction of hypertension. Conclusion: These findings represent specific alterations in microbial diversity, genes, species and functions of the hypertensive gut microbiome. Further studies on the causality relationship between hypertension and gut microbiota will offer new prospects for treating and preventing the hypertension and its associated diseases.

CCl4-induced hepatotoxicity: protective effect of rutin on p53, CYP2E1 and the antioxidative status in rat

Abstract: Rutin is a polyphenolic natural flavonoid which possesses antioxidant and anticancer activity. In the present study the hepatoprotective effect of rutin was evaluated against carbon tetrachloride (CCl4)-induced liver injuries in rats. 24 Sprague–Dawley male rats were equally divided into 4 groups for the assessment of hepatoprotective potential of rutin. Rats of group I (control) received only vehicles; 1 ml/kg bw of saline (0.85%) and olive oil (3 ml/kg) and had free access to food and water. Rats of group II, III and IV were treated with CCl4 (30% in olive oil, 3 ml/kg bw) via the intraperitoneal route twice a week for four weeks. The rutin at the doses of 50 and 70 mg/kg were administered intragastrically after 48 h of CCl4 treatment to group III and IV, respectively. Protective effect of rutin on serum enzyme level, lipid profile, activities of antioxidant enzymes and molecular markers were calculated in CCl4-induced hepatotoxicity in rat. Rutin showed significant protection with the depletion of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma glutamyl transpeptidase (γ-GT) in serum as was raised by the induction of CCl4. Concentration of serum triglycerides, total cholesterol and low density lipoproteins was increased while high-density lipoprotein was decreased with rutin in a dose dependent manner. Activity level of endogenous liver antioxidant enzymes; catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSHpx), glutathione-S-transferase (GST) and glutathione reductase (GSR) and glutathione (GSH) contents were increased while lipid peroxidation (TBARS) was decreased dose dependently with rutin. Moreover, increase in DNA fragmentation and oxo8dG damages while decrease in p53 and CYP 2E1 expression induced with CCl4 was restored with the treatment of rutin. From these results, it is suggested that rutin possesses hepatoprotective properties.

The Role of Oxidative Stress and Antioxidants in Liver Diseases

Abstract: A complex antioxidant system has been developed in mammals to relieve oxidative stress. However, excessive reactive species derived from oxygen and nitrogen may still lead to oxidative damage to tissue and organs. Oxidative stress has been considered as a conjoint pathological mechanism, and it contributes to initiation and progression of liver injury. A lot of risk factors, including alcohol, drugs, environmental pollutants and irradiation, may induce oxidative stress in liver, which in turn results in severe liver diseases, such as alcoholic liver disease and non-alcoholic steatohepatitis. Application of antioxidants signifies a rational curative strategy to prevent and cure liver diseases involving oxidative stress. Although conclusions drawn from clinical studies remain uncertain, animal studies have revealed the promising in vivo therapeutic effect of antioxidants on liver diseases. Natural antioxidants contained in edible or medicinal plants often possess strong antioxidant and free radical scavenging abilities as well as anti-inflammatory action, which are also supposed to be the basis of other bioactivities and health benefits. In this review, PubMed was extensively searched for literature research. The keywords for searching oxidative stress were free radicals, reactive oxygen, nitrogen species, anti-oxidative therapy, Chinese medicines, natural products, antioxidants and liver diseases. The literature, including ours, with studies on oxidative stress and anti-oxidative therapy in liver diseases were the focus. Various factors that cause oxidative stress in liver and effects of antioxidants in the prevention and treatment of liver diseases were summarized, questioned, and discussed.