We investigated the aqueous and ethanolic extracts of different forms (local names: mura and chora) of turmeric (Curcuma longa) from the Khulna and Chittagong divisions of Bangladesh for their antioxidant properties and polyphenol, flavonoid, tannin, and ascorbic acid contents. The antioxidant activity was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicalscavenging activity and ferric reducing antioxidant power (FRAP) values. The ethanolic extract of Chittagong's mura contained the highest concentrations of polyphenols (16.07%), flavonoids (9.66%), and ascorbic acid (0.09 mg/100 g) and chora resulted in high yields (17.39%). The ethanolic extract of Khulna's mura showed a higher DPPH radical-scavenging activity with the lowest 50% inhibitory concentration (IC 50 ) (1.08 g/mL), while Khulna's chora had the highest FRAP value (4204.46 ± 74.48 M Fe [II] per 100 g). Overall, the ethanolic extract had higher antioxidant properties than those in the aqueous extract. However, the tannin concentration was lower in the ethanolic extract. We conclude that the turmeric varieties investigated in this study are useful sources of natural antioxidants, which confer significant protection against free radical damage.

We investigated the protective role of Withania somnifera leaf extract (WSLEt) on isoproterenol- (ISO-) induced myocardial infarction (MI) in rats. Subcutaneous injection of ISO (85 mg/kg body weight (b.w.)) administered to rats for two consecutive days caused a significant increase in cardiac troponin I (cTnI) levels and serum lipid profiles, as well as the activities of some marker enzymes. In addition to these diagnostic markers, there were increased levels of lipid peroxidation (LPO) and decreased activities of enzymatic antioxidants (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRx), and glutathione-S-transferase (GST)) in the myocardium. However, oral pretreatment (100 mg/kg b.w.) with WSLEt for 4 weeks elicited a significant cardioprotective activity by lowering the levels of cTnI, lipid profiles, and marker enzymes. The levels of LPO products were also significantly decreased. Elevated activities of antioxidant enzymes were also observed in rats pretreated with WSLEt. As further confirmed histopathologically, our findings strongly suggest that the cardioprotective effect of WSLEt on myocardium experiencing ISO-induced oxidative damage may be due to an augmentation of the endogenous antioxidant system and an inhibition of LPO in the myocardial membrane. We conclude that WSLEt confers some protection against oxidative damage in ISO-induced MI in rats.

The present study was designed to investigate the cardioprotective effects of Malaysian Tualang honey against isoproterenol- (ISO-) induced myocardial infarction (MI) in rats by investigating changes in the levels of cardiac marker enzymes, cardiac troponin I (cTnI), triglycerides (TG), total cholesterol (TC), lipid peroxidation (LPO) products, and antioxidant defense system combined with histopathological examination. Male albino Wistar rats (n = 40) were pretreated orally with Tualang honey (3 g/kg/day) for 45 days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes (creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and aspartate transaminase (AST)), cTnI, serum TC, and TG levels. In addition, ISO-induced myocardial injury was confirmed by a significant increase in heart lipid peroxidation (LPO) products (TBARS) and a significant decrease in antioxidant enzymes (SOD, GPx, GRx, and GST). Pretreatment of ischemic rats with Tualang honey conferred significant protective effects on all of the investigated biochemical parameters. The biochemical findings were further confirmed by histopathological examination in both Tualang-honey-pretreated and ISO-treated hearts. The present study demonstrates that Tualang honey confers cardioprotective effects on ISO-induced oxidative stress by contributing to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation.

Propolis contains high concentrations of polyphenols, flavonoids, tannins, ascorbic acid, and reducing sugars and proteins. Malaysian Propolis (MP) has been reported to exhibit high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing antioxidant power (FRAP) values. Herein, we report the antioxidant properties and cardioprotective properties of MP in isoproterenol- (ISO-) induced myocardial infarction in rats. Male Wistar rats (n = 32) were pretreated orally with an ethanol extract of MP (100 mg/kg/day) for 30 consecutive days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes and cardiac troponin I levels and altered serum lipid profiles. In addition significantly increased lipid peroxides and decreased activities of cellular antioxidant defense enzymes were observed in the myocardium. However, pretreatment of ischemic rats with MP ameliorated the biochemical parameters, indicating the protective effect of MP against ISO-induced ischemia in rats. Histopathological findings obtained for the myocardium further confirmed the biochemical findings. It is concluded that MP exhibits cardioprotective activity against ISO-induced oxidative stress through its direct cytotoxic radical-scavenging activities. It is also plausible that MP contributed to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation.

The present study was designed to investigate the cardioprotective effects of Sundarban honey (SH) in rats with isoproterenol- (ISO-) induced myocardial infarction. Adult male Wistar Albino rats were pretreated with Sundarban honey (5 g/kg) daily for a period of 6 weeks. After the treatment period, ISO (85 mg/kg) was subcutaneously injected into the rats at 24 h intervals for 2 days. ISO-induced myocardial damage was indicated by increased serum cardiac specific troponin I levels and cardiac marker enzyme activities including creatine kinase-MB, lactate dehydrogenase, aspartate transaminase, and alanine transaminase. Significant increases in serum total cholesterol, triglycerides, and low-density lipoprotein-cholesterol levels were also observed, along with a reduction in the serum high-density lipoprotein-cholesterol level. In addition to these diagnostic markers, the levels of lipid peroxide products were significantly increased. The activities of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, and glutathione reductase were significantly decreased in the hearts after ISO-induced myocardial infarction. However, pretreatment of ischemic rats with Sundarban honey brought the biochemical parameters to near normalcy, indicating the protective effect of Sundarban honey against ISO-induced ischemia in rats. Histopathological findings of the heart tissues further confirmed the biochemical findings, indicating that Sundarban honey confers protection against ISO-induced oxidative stress in the myocardium.

No abstract

Seven transmembrane G protein-coupled receptors (GPCRs) have gained much interest in recent years as it is the largest class among cell surface receptors. G proteins lie in the heart of GPCRs signalling and therefore can be therapeutically targeted to overcome complexities in GPCR responses and signalling. G proteins are classified into four families (G, G, G and G); G is further subdivided into four classes. Among them G and G isoforms are most crucial and ubiquitously expressed; these isoforms are almost 88% similar at their amino acid sequence but may exhibit functional divergences. However, uncertainties often arise about G and G inhibitors, these G proteins might also have suitability to the invention of novel-specific inhibitors for each isoforms. YM-254890 and UBO-QIC are discovered as potent inhibitors of G functions and also investigated in thrombin protease-activated receptor (PAR)-1 inhibitors and platelet aggregation inhibition. The most likely G protein involved in PAR-1 stimulates responses is one of the G family isoforms. In this review, we highlight the molecular structures and pharmacological responses of G family which may reflect the biochemical and molecular role of G and G. The advanced understanding of G and G role in GPCR signalling may shed light on our understanding on cell biology, cellular physiology and pathophysiology and also lead to the development of novel therapeutic agents for a number of diseases.

Honey, a supersaturated natural product of honey bees, contains complex compounds with antioxidant properties and therefore has a wide a range of applications in both traditional and modern medicine. In the present study, the protective effects of Sundarban honey from Bangladesh against acetaminophen- (APAP-) induced hepatotoxicity and nephrotoxicity in experimental rats were investigated. Adult male Wistar rats were pretreated with honey (5 g/kg) for 4 weeks, followed by the induction of hepatotoxicity and nephrotoxicity via the oral administration of a single dose of APAP (2 g/kg). Organ damage was confirmed by measuring the elevation of serum alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST), total protein (TP), total bilirubin (TB), urea, creatinine, and malondialdehyde (MDA). Histopathological alterations observed in the livers and the kidneys further confirmed oxidative damage to these tissues. Animals pretreated with Sundarban honey showed significantly markedly reduced levels of all of the investigated parameters. In addition, Sundarban honey ameliorated the altered hepatic and renal morphology in APAP-treated rats. Overall, our findings indicate that Sundarban honey protects against APAP-induced acute hepatic and renal damage, which could be attributed to the honey's antioxidant properties.