Cytotoxic and Antitumoral Effects of Methanolic Extracts of Avocado Fruit Mesocarp in Colorectal Cancer Cell Line HT29.

Colorectal cancer is a widespread neoplasia with high ratios of chemoresistance. Phytochemicals in plant-based extracts could be useful to treat colorectal cancer, and/or reduce chemoresistance. Methanolic extract of avocado mesocarp (MEAM) has demonstrated antitumoral properties, depending on the fruit ripening stage (RS). The aim of this study was to analyze the effects of methanolic extracts of "Hass" avocado fruit at different RS on cytotoxicity, antioxidative, anti-inflammatory, anti-invasive, cell cycle, and epithelial-mesenchymal transition inhibition in colorectal adenocarcinoma cell line HT29. The MEAM showed an increasing concentration of total phenolic compounds as the RS progressed, which was correlated with antioxidant capacity measured by the Ferric Reducing Antioxidant Power assay but not with the 2.2-diphenyl-1-picrylhydrazyl assay. The specific phenolic compounds of MEAM were determined by high-performance liquid chromatography, and it was found that concentrations of epicatechin decreased while concentrations of chlorogenic acid increased as the RS progressed. The HT29 cell line was treated with MEAM for 48 h, and all MEAM had a cytotoxic effect, reported by MTT assay, nevertheless, the strongest effect was associated with the presence of chlorogenic acid. MEAM induced apoptosis and cell cycle arrest in phase G0/G1, reported by flow cytometry. Moreover, MEAM inhibited cell migration evidenced by the wound healing assay. On the other hand, MEAM significantly reduced expression of mRNA of tumor necrosis factor-alpha and cyclooxygenase 2. These effects comprise important inhibition of some hallmarks of cancer. This, in turn, may provide interesting guidelines for developing antitumoral intervention agents.

Zinc Oxide Nanoparticles and Zinc Sulfate Impact Physiological Parameters and Boosts Lipid Peroxidation in Soil Grown Coriander Plants (Coriandrum sativum).

The objective of this study was to determine the oxidative stress and the physiological and antioxidant responses of coriander plants (Coriandrum sativum) grown for 58 days in soil with zinc oxide nanoparticles (ZnO NPs) and zinc sulfate (ZnSO4) at concentrations of 0, 100, 200, 300, and 400 mg of Zn/kg of soil. The results revealed that all Zn compounds increased the total chlorophyll content (CHLt) by at least 45%, compared to the control group; however, with 400 mg/kg of ZnSO4, chlorophyll accumulation decreased by 34.6%. Zn determination by induction-plasma-coupled atomic emission spectrometry (ICP-AES) showed that Zn absorption in roots and shoots occurred in plants exposed to ZnSO4 at all concentrations, which resulted in high levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA). Only at 400 mg/kg of ZnSO4, a 78.6% decrease in the MDA levels was observed. According to the results, the ZnSO4 treatments were more effective than the ZnO NPs to increase the antioxidant activity of catalase (CAT), ascorbate peroxidase (APX), and peroxidases (POD). The results corroborate that phytotoxicity was higher in plants subjected to ZnSO4 compared to treatments with ZnO NPs, which suggests that the toxicity was due to Zn accumulation in the tissues by absorbing dissolved Zn++ ions.

Foliar Application of Zinc Oxide Nanoparticles and Zinc Sulfate Boosts the Content of Bioactive Compounds in Habanero Peppers.

The physiological responses of habanero pepper plants (Capsicum chinense Jacq.) to foliar applications of zinc sulphate and zinc nano-fertilizer were evaluated in greenhouse trials. The effect of the supplement on fruit quality of habanero pepper was particularly observed. Habanero pepper plants were grown to maturity, and during the main stages of phenological development, they were treated with foliar applications of Zn at concentrations of 1000 and 2000 mg L-1 in the form of zinc sulfate (ZnSO4) and zinc oxide nanoparticles (ZnO NPs). Additional Zn was not supplied to the control treatment plants. ZnO NPs at a concentration of 1000 mg L-1 positively affected plant height, stem diameter, and chlorophyll content, and increased fruit yield and biomass accumulation compared to control and ZnSO4 treatments. ZnO NPs at 2000 mg L-1 negatively affected plant growth but significantly increased fruit quality, capsaicin content by 19.3%, dihydrocapsaicin by 10.9%, and Scoville Heat Units by 16.4%. In addition, at 2000 ZnO NPs mg L-1 also increased content of total phenols and total flavonoids (soluble + bound) in fruits (14.50% and 26.9%, respectively), which resulted in higher antioxidant capacity in ABTS (2,2'azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), DPPH (2,2-diphenyl-1-picrylhydrazyl), and FRAP (ferric reducing antioxidant power) (15.4%, 31.8%, and 20.5%, respectively). These results indicate that application of ZnO NPs could be employed in habanero pepper production to improve yield, quality, and nutraceutical properties of fruits.