Preliminary study of the antioxidant properties of flowers and roots of Pyrostegia venusta (Ker Gawl) Miers

<p>Abstract</p> <p>Background</p> <p>Free radical stress leads to tissue injury and can eventually to arthritis, atherosclerosis, diabetes mellitus, neurodegenerative diseases and carcinogenesis. Several studies are ongoing worldwide to find natural antioxidants of plant origin. We assessed the <it>in-vitro </it>antioxidant activities and screened the phytochemical constituents of methanolic extracts of <it>Pyrostegia venusta </it>(Ker Gawl) <it>Miers</it>.</p> <p>Methods</p> <p>We evaluated the antioxidant potential and phytochemical constituents of <it>P. venusta </it>using 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2, 2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays. Gas chromatography-mass spectroscopy (GC-MS) studies were also undertaken to assess the phytochemical composition of the flower extracts.</p> <p>Results</p> <p>Phytochemical analyses revealed the presence of terpenoids, alkaloids, tannins, steroids, and saponins. The reducing ability of both extracts was in the range (in μm Fe(II)/g) of 112.49-3046.98 compared with butylated hydroxytoluene (BHT; 63.56 ± 2.62), catechin (972.02 ± 0.72 μm) and quercetin 3208.27 ± 31.29. A significant inhibitory effect of extracts of flowers (IC₅₀= 0.018 ± 0.69 mg/ml) and roots (IC₅₀= 0.026 ± 0.94 mg/ml) on ABTS free radicals was detected. The antioxidant activity of the extracts of flowers (95%) and roots (94%) on DPPH radicals was comparable with that of ascorbic acid (98.9%) and BHT (97.6%). GC-MS study revealed the presence of myoinositol, hexadecanoic acid, linoleic acid, palmitic acid and oleic acid in the flower extracts.</p> <p>Conclusion</p> <p>These data suggest that <it>P. venusta </it>is a natural source of antioxidants. The extracts of flowers and roots of <it>P. venusta </it>contain significant amounts of phytochemicals with antioxidative properties and could serve as inhibitors or scavengers of free radicals. <it>P. venusta </it>could be exploited as a potential source for plant-based pharmaceutical products. These results could form a sound basis for further investigation in the potential discovery of new natural bioactive compounds.</p

Accommodating practices during episodes of disillusionment with mobile IT

This study investigates how tablet users react when technology falls short of their expectations. We deploy a data/frame model to study this process and investigate resistance-related reactions and the deployment of accommodating practices at the individual level. Analyzing user blogs that provide narratives on user interaction with tablets, we identify triggers of episodes of disillusionment and illustrate five sensemaking paths that users follow, eventually leading to one of three practices: 1) users choose to defer tasks until the situation changes, or they abandon the platform altogether; 2) they develop workarounds at different levels of proficiency; or 3) they proceed by reframing their expectations of the platform. By revealing user decision-making process during episodes of disillusionment, the findings contribute to information systems post-adoption research. At a practical level, the findings inform IT artifact and application design by offering insights on how users process discrepancies between their expectations and actual use experience

Role of outer membrane proteins in immunity against murine salmonellosis-1. Antibody response to crude outer membrane proteins of Salmonella typhimurium

The humoral immune response to crude outer membrane proteins (comp) of S. typhimurium in mice has been characterized. Maximal and quicker antibody response was observed when 50 micrograms of comp was injected intraperitoneally. The comp of smooth C5 strain of S. typhimurium evoked antibody response to both lipopolysaccharide (LPS) and proteins. Absorption of these sera with LPS coated erythrocytes eliminated the antibodies to LPS completely, while the antibody level to protein was left unaltered. The comp from rough mutant (lacking O-specific chain of LPS) of S. typhimurium elicited antibodies to proteins but not to LPS. These results indicate the concomitant production of antibodies to Salmonella outer membrane proteins also. The significance of such antibodies in protection and diagnosis has been discussed

Hypoglycemic effect of aqueous extract of Parthenium hysterophorus L. in normal and alloxan induced diabetic rats

Objectives: To study the effects of Parthenium hysterophorus   L. flower on serum glucose level in normal and alloxan induced diabetic rats. Materials and Methods: Albino rats were divided into six groups of six animals each, three groups of normal animals receiving different treatments consisting of vehicle, aqueous extract of Parthenium hysterophorus L. flower (100 mg/kg) and the standard antidiabetic drug, glibenclamide (0.5 mg/kg). The same treatment was given to the other three groups comprising alloxan induced diabetic animals. Fasting blood glucose level was estimated using the glucose oxidase method in normal and alloxan induced diabetic rats, before and 2 h after the administration of drugs. Results: Parthenium hysterophorus L. showed significant reduction in blood glucose level in the diabetic (P < 0.01) rats. However, the reduction in blood glucose level with aqueous extract was less than with the standard drug glibenclamide. The extract showed less hypoglycemic effect in fasted normal rats, (P< 0.05). Conclusion: The study reveals that the active fraction of Parthenium hysterophorus L. flower extract is very promising for developing standardized phytomedicine for diabetes mellitus

Antioxidant and antimicrobial activity evaluation of polyhydroxycinnamic acid ester derivatives

252-257Polyhydroxycinnamic acid esters 5a-p have been synthesized starting from the appropriately substituted benzaldehydes. The antioxidant activity of these esters has been determined by superoxide free radical scavenging activity and DPPH free radical scavenging activity. The SAR studies reveal that pyrogallol, catechol moieties are essential for good antioxidant activity and an increase in the length of alkyl chain of the ester decreases the activity. Butyl hydroxycinnamates exhibit higher antibacterial activity among the synthesized hydroxycinnamates 5a-p, but, none of these show significant antifungal activity

General Public Knowledge of Coronavirus Disease 2019 (COVID-19) at Early Stages of the Pandemic: A Random Online Survey in Saudi Arabia

open access articleBackground: A novel coronavirus was identified at the end of 2019 in Wuhan City, China. Later, it was named as coronavirus disease 2019 (COVID-19) and declared a pandemic in March 2020. Saudi and global health agencies have provided various COVID-19 knowledge tools and facts to the general public. Therefore, this study aims to assess COVID-19 knowledge among the general public in Saudi Arabia at the early stages of the pandemic. Participants and Methods: A cross-sectional study was conducted in March 2020 in Saudi Arabia. The study included 1006 participants who responded to a random online COVID-19 public knowledge questionnaire that included five sections: demographic characteristics, general knowledge, prevention practices, home quarantine measures, and knowledge of governmental restrictions. Three levels of knowledge were established: excellent, intermediate, and poor. Differences in the percentages of participants with different knowledge levels by the demographic variables were analyzed using the chi-square test. Results: Regarding overall general knowledge of COVID-19, 75%, 24%, and 1% of the participants had excellent, intermediate, and poor knowledge levels, respectively. Knowledge levels were significantly different by nationality and age (P=0.027 and 0.008, respectively). Most participants (98.4%) reported excellent knowledge of prevention practices, with no statistically significant differences among groups (P> 0.005). Older age groups reported higher knowledge of home quarantine measures (86.6% and 86.4% of the 51– 60 and older than 60 age groups, respectively, P=0.001). Conclusion and Recommendations: High levels of knowledge about the virus, including prevention practices, are essential. The provision of COVID-19 facts and knowledge tools should be focused on younger generations to enhance compliance with the governmental restrictions required to stop the spread of COVID-19