Comparative study of phenolic profile, antioxidant and antimicrobial activities of aqueous extract of white and green tea.

The sole difference between white tea (WT) and green tea (GT) is the former that made only from the buds and young leaves of the Camelia sinensis plant, whilst the latter is made from matured tea leaves. The phytochemical profiles, phenolic compounds, antioxidant, and antimicrobial activity of two varieties of Camellia sinensis teas, white and green, were compared in this study. Total antioxidant capacity, reducing power, DPPH radical scavenging, and Fe+2 chelating activities were used to determine antioxidant activities in water extract of GT and WT. The largest level of phenolic content was discovered in WGTE compared with the lowest amount was found in WWTE (290.67 mg/100 g tea and 185.96 mg/100 g tea, respectively). Phenoilc acids (gallic, benzoic, chlorogenic, ellagic, and ρ-coumaric acids) and flavonoids (rutin and kampherol) were found in the two extracts. The findings of DPPH radical scavenging assays were 84.06 and 82.37% inhibition. In vitro antimicrobial activity was indicated that (WWTE and WGTE) had a high level of activity against Staphylococcus aureus, and gave negative activity against Salmonella typhimurium, and Aspergillus Niger. The WT and GT extracts are a great source of natural antioxidants with biological effects on human health.

Insecticide potentiality of rice case (chaff) particle.

Chaff (the outermost protective layer of rice grain) in nano and ground sized particles was bio-assessed to explore its insecticidal effects against the greater wax moth, Galleria mellonella (Lepidoptera: Pyralidae). These particles induced remarkable disturbances in the biological patterns of the greater wax moth. These were cleared as they exhibited insecticidal impact on both juvenile and adult stages, their impacts on larval, pupal and adult death, the formation of morphogenetic features (permanent larvae and larval-pupal intermediates), their negative influence on the adult emergence and the potentialities of the applied concentrations to hinder the larval weight gain. The recorded LC50 values proved more larvicidal potency of the nano-sized particle than that of the ground rice chaff one. The transverse sections in the midgut of the 20 days old larvae (both treated and untreated ones) confirmed the histopathological deformations of the examined particles. The high siliceous content of the chaff particle may be responsible for such recorded disturbances.

Evaluation of the therapeutic effects of rice husk nanosilica combined with platelet-derived growth factor in hepatic veno-occlusive disease.

Veno-occlusive disease is an important pattern of hepatotoxicity associated with antineoplastic drugs. The study investigated the possible therapeutic effects of RHS nanoparticles combined with a PDGF on veno-occlusive disease (VOD) in liver elicited in rats with DAC. In this work, nanosilica (SiO2) was successfully prepared from rice husk, and its physicochemical characteristics were investigated using EDX, XRD, N2 adsorption-desorption isotherm, SEM, and TEM. Forty-eight male Sprague-Dawely rats were distributed into 6 groups, with 8 rats in each. The first group served as the control. In the second group, animals were infused with DAC (0.015 mg/kg; 1-3 days) by intraperitoneal injection (i.p.). In the third group, rats were injected i.p. with DAC, and then at 24 h following the last dose of DAC, received nano-RHS incorporated with PDGF twice a week for 4 weeks. In the fourth group, normal animals were injected with RHS. In the fifth group, normal rats received PDGF, and in the sixth group, normal rats received nano-RHS combined with PDGF. The prepared nanosilica showed type II adsorption isotherm characteristic for mesoporous materials with a specific surface area of 236 m2/g. TEM imaging confirmed the production of nanoparticles via the followed preparation procedure. Radical scavenging potential for nano-RHS was determined using two different in-vitro assays: DPPH, and ABTS radicals. The results of this work show that administration of nano-RHS combined with PDGF significantly reversed the oxidative stress effects of DAC as evidenced by a decrease in liver function. It can be concluded that the nano-RHS combined with PDGF is useful in preventing oxidative stress and hepatic VOD induced by chemotherapy such as DAC.