Comparative study of chemically synthesized and low temperature bio-inspired Musa acuminata peel extract mediated zinc oxide nanoparticles for enhanced visible-photocatalytic degradation of organic contaminants in wastewater treatment.

Zinc oxide (ZnO) photocatalysts were successfully synthesized via chemical and green, environmentally-benign methods. The work highlights the valorization of banana peel (BP) waste extract as the reducing and capping agents to produce pure, low temperature, highly crystalline, and effective ZnO nanoparticles with superior photocatalytic activities for the removal of hazardous Basic Blue 9 (BB9), crystal violet (CV), and cresol red (CR) dyes in comparison to chemically synthesized ZnO. Their formation and morphologies were verified by various optical spectroscopic and electron microscopic techniques. XRD results revealed that the biosynthesized ZnO exhibited 15.3 nm crystallite size when determined by Scherrer equation, which was smaller than the chemically synthesized ZnO. The FTIR spectra confirmed the presence of biomolecules in the green-mediated catalyst. EDX and XPS analyses verified the purity and chemical composition of ZnO. Nitrogen sorption analysis affirmed the high surface area of bio-inspired ZnO. Maximum removal efficiencies were achieved with 30 mg green ZnO catalyst, 2.0 × 10-5 M BB9 solution, alkaline pH 12, and irradiation time 90 min. Green-mediated ZnO showed superior photodegradation efficiency and reusability than chemically synthesized ZnO. Therefore, this economical, environment-friendly photocatalyst is applicable for the removal of organic contaminants in wastewater treatment under visible light irradiation.

Effect of alpha lipoic acid on oxidative stress and vascular wall of diabetic rats.

UNLABELLED: PREMISES AND OBJECTIVES: Antioxidant plays an important role in preventing the progression of diabetes mellitus (DM) complications. The aim of the present study was to investigate the effect of alpha lipoic acid (ALA) supplementation on plasma lipid, oxidative stress and vascular changes in diabetic rats. MATERIAL AND METHODS: Diabetes was induced by a single intravenous injection of streptozotocin (STZ) (50 mg/kg). The diabetic rats were divided into two groups: (i) supplemented group with ALA (100 mg/kg/day) and (ii) non-supplemented group without ALA. Non-diabetic rats (NDM) formed the control group, which received saline injection. RESULTS: Following eight weeks of supplementation, fasting blood glucose (FBG) and glycosylated hemoglobin (HBA1c) in ALA-supplemented rats was found to be significantly lower than the non-supplemented group. ALA-supplementation also improved dyslipidemia that occurred in diabetic rats. ALA-supplementation also significantly increased plasma superoxide dismutase (SOD) activity and vitamin C level as compared to the No Suppl group. The increase in plasma and aorta malondealdehyde + 4-hydroxynonenal (MDA + 4-HNE) levels were also inhibited and the levels of oxidative DNA damage of peripheral lymphocytes were significantly reduced. Electron microscopic examination of thoracic aorta revealed that normal tissue organization was disrupted in STZ-diabetic rats with ALA-supplementation reducing the changes in the vascular morphology. CONCLUSIONS: It is concluded that ALA has the potential in preventing the alteration of vascular morphology in diabetic rats probably through the improvement of glycemic status and dyslipidemia as well as its antioxidant activities.