RESUMO: Nanoemulsão óleo/água (O/A) contendo extrato de goldenberry foi elaborada utilizando método de banho ultrassônico de alta energia. A caracterização físico-química da formulação foi realizada pela determinação do pH, diâmetro médio de gotas, índice de polidispersão (PDI) e potencial zeta. A toxicidade das nanoemulsões foi avaliada utilizando ensaios in vitro com linhas celulares tumorais e não tumorais e in vivo utilizando Caenorhabditis elegans. O pH da nanoemulsão foi de 3,84, o diâmetro médio das gotículas foi de 268 ± 7 nm, PDI 0,113 e o potencial zeta -13,94 mV. Os resultados dos ensaios de citotoxicidade empregando células não tumorais indicaram que o extrato associado ou não à nanoemulsão manteve a viabilidade celular em diferentes concentrações testadas. Nos ensaios, utilizando linhagem tumoral, observou-se que a nanoemulsão contendo o extrato apresentou maior atividade antitumoral do que o extrato livre. Quanto aos testes in vivo, não houve mudança na taxa de sobrevivência dos vermes.

ABSTRACT: Oil-in-water (O/W) nanoemulsion containing goldenberry extract was elaborated using a high-energy ultrasonic bath method. Physicochemical characterization of the formulation was carried out by determining pH, mean droplet diameter, polydispersity index (PDI) and zeta potential. Nanoemulsion toxicity was assessed using in vitro assays with tumor and non-tumor cell lines, and in vivo using Caenorhabditis elegans. The pH of the nanoemulsion was 3.84, the mean droplet diameter was 268 ± 7 nm, PDI 0.113 and zeta potential -13.94 mV. Results of the cytotoxicity assays employing non-tumor cells indicated that the extract associated or not with nanoemulsion maintained cell viability at different concentrations tested. In the assays using tumor lineage, it is observed that the nanoemulsion containing the extract had higher antitumor activity than the free extract. As for the in vivo tests, there was no change in the survival rate of the worms.

Rice is a tropical plant, so cold temperature may be detrimental to its development, depending on the genotype and environmental conditions. Degree of lipid unsaturation has been related to cold tolerance due to its effect on membrane stability. So, the aim of this study was to characterize the fatty acid composition and its alterations due to cold temperature in rice genotypes of diversified origin. Forty-four rice genotypes at the V4 stage were submitted to two temperature conditions: 10°C and 28°C for two days and after this they had their leaves collected for lipid extraction and quantification. Control plants were allowed to regrow until presenting four leaves fully expanded and then were subjected to 10°C for ten days for cold tolerance evaluation. Plant survival was measured seven days after recovery at 28°C and the genotypes were grouped in three cold tolerance classes: tolerant, intermediate and sensitive. These classes differed for total saturated and unsaturated fatty acids only under the cold temperature treatment. Further analysis of the more abundant fatty acids: linoleic, linolenic and palmitic, showed that the two last ones differed between tolerant and sensitive genotypes. Linolenic acid increased after cold exposure in cold tolerant genotypes while palmitic acid decreased, and an opposite behavior was found in the cold sensitive genotypes. These evidences indicate that these fatty acids are potential molecular markers useful for breeding programs as well as for future basic studies on cold tolerance in rice.