Enhancement of shelf-life of food items via immobilized enzyme nanoparticles on varied supports. A sustainable approach towards food safety and sustainability.

This study was designed to extend the shelf life of fruits and vegetables through a novel technique based on utilization of microbially driven enzyme glucose oxidase and casting a fine layer of hydrogen peroxide on the food item that protected the fruit from decay. The produced nanoparticles (ZnO, Ag) were ligated with Glucose Oxidize (GOx) purified from Aspergillus niger. Post ligation studies revealed that ligated enzymes display relatively enhanced activity. Four types of sprays were prepared in order to compare their effectiveness. Glucose oxidase/silver nanoparticles (GOx/AgNPs), glucose oxidase/zinc oxide nanoparticles (GOx/ZnONPs), AgNPs and ZnONPs sprays were applied to guava fruit samples as post-harvest therapeutic agents for a period of 15 days. Fruit quality parameters such as total suspended solids (TSS), pH, weight loss, DPPH free radical capturing performance and firmness confirms that usage of the bioconjugates especially that of GOx/ZnONP was curiously active to maintain the physical appearance of fruit well along with no such deterioration in chemical composition of fruit. Consequently, enzymes ligated on the surface of nanoparticles (ZnONP) are exceptional for extension of post-harvest shelf life of fruits such as guava.

Postharvest shelf life enhancement of peach fruit treated with glucose oxidase immobilized on ZnO nanoparticles.

For the shelf life extension of fruits, we envisioned a novel antimicrobial approach that is based on the production of a thin layer of hydrogen peroxide at the surface of food by utilizing the bioactivity of glucose oxidase (GOx). The enzyme, purified from Aspergillus Niger, was immobilized on zinc oxide nanoparticles and then suspended in a buffer to prepare a spraying solution of GOx/ZnONPs. Post-immobilization analyses indicated that immobilized enzyme showed higher activity as compared to the free enzyme. The GOx/ZnONPs spray was applied for postharvest treatment of peach. The control and treatment groups were stored at ambient conditions for fifteen days and standard quality parameters were analyzed. In contrast to the control group, the GOx/ZnONPs spray treatment was remarkably effective in maintaining the physiological appearance of fruits even more than 12 days and showed a significant reduction in the decrease of weight, firmness, TSS, and DPPH free radical scavenging activity of fruits. Thus GOx/ZnONPs is an excellent platform to extend the postharvest shelf life of peach.

Minocycline-Derived Silver Nanoparticles for Assessment of Their Antidiabetic Potential against Alloxan-Induced Diabetic Mice.

Diabetes is a life-threatening disease, and chronic diabetes affects parts of the body including the liver, kidney, and pancreas. The root cause of diabetes is mainly associated with oxidative stress produced by reactive oxygen species. Minocycline is a drug with a multi-substituted phenol ring and has shown excellent antioxidant activities. The objective of the present study was to investigate the antidiabetic potential of minocycline-modified silver nanoparticles (mino/AgNPs) against alloxan-induced diabetic mice. The mino/AgNPs were synthesized using minocycline as reducing and stabilizing agents. UV-visible, FT-IR, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were applied for the characterization of mino/AgNPs. A 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay was conducted to determine the antioxidant potential of newly synthesized mino/AgNPs. The results revealed that the mino/AgNPs showed higher radical scavenging activity (IC50 = 19.7 µg/mL) compared to the minocycline (IC50 = 26.0 µg/mL) and ascorbic acid (IC50 = 25.2 µg/mL). Further, mino/AgNPs were successfully employed to examine their antidiabetic potential against alloxan-induced diabetic mice. Hematological results showed that the mice treated with mino/AgNPs demonstrated a significant decrease in fasting blood glucose level and lipid profile compared to the untreated diabetic group. A histopathological examination confirmed that the diabetic mice treated with mino/AgNPs showed significant recovery and revival of the histo-morphology of the kidney, central vein of the liver, and islet cells of the pancreas compared to the untreated diabetic mice. Hence, mino/AgNPs have good antidiabetic potential and could be an appropriate nanomedicine to prevent the development of diabetes.

Changes in thyroid function status of suicidal patients

Abstract Background This study was carried out at Punjab Institute of Mental Health and Centre for Nuclear Medicine Mayo Hospital, Lahore. It is aimed at the possible association of thyroid malfunctioning with suicide attempts of patients. Objective Determination of thyroid function status of suicidal psychiatric patients and their comparison with psychiatric patients without suicide attempt or ideation. Methods Total 54 patients with either past history of suicide attempt or current suicidal ideation were selected for analysis of their thyroid function status (age 15-55 years). Age matched 50 non-suicide psychiatric patients were included for comparison. Results Two patients with suicide attempt had overt thyroid dysfunction. Remaining patients had serum FT4, FT3 and TSH level within normal range. Suicide attempter patients had lower FT4 but increased FT3 and TSH levels compared to suicidal ideation patients. Serum FT4 and TSH levels in suicidal patients were not different from psychiatric patients. Serum FT3 in suicidal patients was lower than psychiatric patients (3.7 ± 0.8 vs. 4.3 ± 0.5; p < 0.05). Female suicidal patients had lower FT3 levels compared to male patients (3.4 ± 0.6 vs. 3.9 ± 0.8 pmol/L; p < 0.05). Discussion Local suicidal patients have higher incidence of overt thyroid disorder and lower FT3 levels compared to non-suicidal psychiatric patients.