Caracterização química e avaliação das atividades biológicas de extratos da polpa de Melocactus zehntneri (Britton & Rose)

Abstract

In order to correlate the popular use plants and to identify new biomolecules, cacti become the aim of this study for phytochemical and pharmacological. In this context, the present work obtained six serial extracts from the cladode cactus internal part-pulpof Melocactus zehntneri and evaluated their potential antioxidants and biological through different assays using in vitro and in vivo methods. The extraction process was done using the lyophilized pulp and apolar and polar solvents, thus generating six extracts: hexane (HE), chloroform (CE), ethanol (EE), methanol (ME), final water (FWE) and only water (WE). First, sugar, protein and phenolic compounds were measured. Then, thin layer chromatography (TLC) has shown the presence of terpenes (ursolic and oleanolic acids), saponins, sugars (raffinose, fructose, sucrose and galactose), glycoproteins, as well as uronic and glucuronic acids using the descending cellulose TLC. In high performance liquid chromatography (HPLC), the preliminary results suggested the presence of phenylpropanoids, such as coumaric acids, benzoic acid, luteolin, hesperidin and ellagic acid. Moreover, the antioxidant assays were done using different concentrations (25, 50, 100, 250 and 500 μg/mL). The extracts presented an antioxidant activity at the Iron Ion Chelation, DPPH, Superoxide Ion Scavenging Assay, Hydroxyl Radical Scavenging Assay. When, it was evaluated the antibiofilm activity against the bacterium Staphylococcus epidermidis 70D MRSE, it was observed an inhibitory action in the formation of the biofilm in almost all the extracts. Moreover, it was important to observe that the aqueous extract (WE) presented the highest percentage of biofilm inhibition - 90%. Furthermore, it was evaluated if these extracts were cytotoxic for 3T3 cell line (fibroblast cells). The data showed that no cytotoxicity was observed in most of the extracts. Based on these results, it was analysed the possible protective activity from these extracts in the H2O2 presence for the 3T3 cell lines. Then, it was observed that these extracts presented a curative activity (they treated the cells). As the antioxidant activity is also associated to cell protection, then it was analysed in vitro photoprotective activity. It was observed that HE and CE extracts presented this activity, with the values of 2,4 and 3,2 respectively. Then, it was showed a potential photoprotective activity. Therefore, the results obtained showed the potential of these extracts to act as antioxidants, antibiofilm, not cytotoxicity and with curative action against H2O2 stress and activity in sunscreens, as additives.