Annamalai University

About: Annamalai University is a education organization based out in Chidambaram, Tamil Nadu, India. It is known for research contribution in the topics: Lipid peroxidation & Antioxidant. The organization has 8098 authors who have published 10758 publications receiving 203872 citations.

Evaluation of leaf extracts of Vitex negundo L. (Family: Verbenaceae) against larvae of Culex tritaeniorhynchus and repellent activity on adult vector mosquitoes.

Abstract: Petroleum ether (60–80°C) extracts of the leaves of Vitex negundo (Verbenaceae) were evaluated for larvicidal activity against larval stages of Culex tritaeniorhynchus in the laboratory. Larvae of C. tritaeniorhynchus were found more susceptible, with LC50 and LC90 values of 2.4883 and 5.1883 mg/l, respectively. Human volunteers wearing special terricot (68:32) fabrics, in the form of armbands, anklets, headbands, collar, and shoulder and pocket strips impregnated with V. negundo leaf extract were used, to test their repellent efficacy at two concentrations viz., 1.5 and 2.0 mg/cm2 under the field conditions. At 1.5-mg/cm2 concentration, more efficacies were found and 6-h complete protection against mosquito bites was provided. Complete protections for 8 h were found at 2.0 mg/cm2 against mosquitoes bites. These results clearly reveal that the V. negundo leaf extract served as a potential larvicidal agent against Japanese encephalitis vector C. tritaeniorhynchus and additionally acted as a promising repellent against various adult vector mosquitoes.

Effect of chemically synthesis compared to biosynthesized ZnO-NPs using Solanum nigrum leaf extract and their photocatalytic, antibacterial and in-vitro antioxidant activity

Abstract: In the present work, chemically synthesized ZnO-NPs were compared with the biosynthesized ZnO-NPs using aqueous leaf extract of Solanum nigrum (5, 10, 15 and 20 ml), at various concentrations. Different techniques like, UV–vis spectroscopy (UV–vis), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Particle size (DLS), Zeta potential (ZE), High resolution transmission electron microscope (HR-TEM) and Fourier transform infrared spectroscopy (FT-IR) were utilized to characterize the synthesized ZnO-NPs. FT-IR study confirmed the presence of falvonoids and proteins in S. nigrum leaf extract, which were the powerful reducing agents responsible for the reduction of zinc acetate salt. The antibacterial and antioxidant activity of Chem ZnO-NPs and biosynthesized ZnO-NPs were investigated with various Gram positive and Gram negative microbes utilizing disk diffusion technique. The obtained result clearly confirmed the biosynthesized ZnO-NPs potentially played as antimicrobial agent against all tested microorganism and a strong antioxidant activity against DPPH free radical scavenging. Photocatalytic degradation of synthesized ZnO-NPs were also evaluated for methylene blue dye degradation under sunlight irradiation and was confirmed that biosynthesized ZnO-NPs had high degradation compared to Chem ZnO-NPs.

Biopolymer gelatin-coated zinc oxide nanoparticles showed high antibacterial, antibiofilm and anti-angiogenic activity.

Abstract: The use of natural polymers in drug design plays an important role in biomedical applications. Combinations of nanoparticles (NPs) and biopolymers have been shown to be useful for many purposes. This study focused on gelatin-coated zinc oxide NPs synthesized by co-precipitation. The particles were characterized by UV–Vis spectrum, showing a main peak at 375 nm. The stability and crystalline nature of the particles was evaluated by Zeta potential and X-ray diffraction analysis. Fourier transform infrared spectroscopy (FTIR) revealed the possible functional groups of Ge-ZnO NPs, with strong bands at 3851, 3447, and 2923 cm− 1. Moreover, transmission electron microscopy (TEM) highlighted the presence of spherically shaped Ge-ZnO NPs that were 20 nm in size. Energy dispersive analysis X-ray (EDX) analysis showed that the zinc elemental content of Ge-ZnO NPs was 59.10%. The results of antibacterial activity assays revealed higher inhibition of Ge-ZnO NPs against Gram-negative Pseudomonas aeruginosa at 100 μg/ml over that against Gram-positive Enterococcus faecalis. Greater inhibition of biofilm formation was observed for Gram-negative bacteria compared to Gram-positive bacteria. In addition, Ge-ZnO NPs effectively inhibited the biofilm growth of the fungus Candida albicans at 50 μg/ml. Ge-ZnO NPs reduced the viability of hepatocarcinoma cancer cell lines at 100 μg/ml. Moreover, in chick embryos, notable anti-angiogenesis effects were observed for Ge-ZnO NPs and zinc acetate at 50 μg/ml compared to that observed testing gelatin. Overall, based on the results, Ge-ZnO NPs may be used as a novel agent for the control of biofilm-forming microbial pathogens.

Combined treatment with naringin and vitamin C ameliorates streptozotocin‐induced diabetes in male Wistar rats

Abstract: Diet and nutrition have substantial impact on reducing the incidence of diabetes mellitus, where oxidative stress is an important etiopathological factor. The combined protective role of low dose of naringin (15 mg kg(-1)) and vitamin C (25 mg kg(-1)) and high dose of naringin (30 mg kg(-1)) and vitamin C (50 mg kg(-1)) on streptozotocin (STZ)-induced toxicity was studied in male Wistar rats. To induce type II diabetes mellitus, rats were injected with STZ intraperitoneally at a dose of 45 mg kg(-1) body weight. STZ-induced diabetic rats showed significant increase in blood glucose, water intake, food intake and glycated hemoglobin and significant decrease in plasma insulin, total hemoglobin, body weight and liver glycogen. Diabetic rats also showed significant decrease in the activity of hexokinase and significant increase in the activities of glucose-6-phosphatase and fructose-1,6-bisphosphatase in liver and kidney. The levels of plasma thiobarbituric acid reactive substances, lipid hydroperoxides and vitamin E were elevated while the level of reduced glutathione was decreased in diabetic rats. Glycoprotein components such as hexose, hexosamine, fucose and sialic acid were increased in plasma, liver and kidney of diabetic rats. Oral administration of high doses of naringin (30 mg kg(-1)) and vitamin C (50 mg kg(-1)) to diabetic rats for a period of 21 days normalized all the above-mentioned biochemical parameters. The effect exerted by naringin (30 mg kg(-1)) and vitamin C (50 mg kg(-1)) was similar to the effect exerted by insulin (6 units kg(-1)). Thus, our study shows the antihyperglycemic and antioxidant effects of naringin and vitamin C in STZ-induced type II diabetes mellitus in rats.