Caracterização fitoquímica e avaliação dos potenciais biológicos do extrato aquoso de Ocimum basilicum

Abstract

The increase in chronic non-communicable diseases (NCDs) has been attributed to factors associated with inadequate lifestyle. In Brazil, in 2019, 41.8% of deaths among individuals aged 30 to 69 were attributed to NCDs. Currently, the search for natural products as a complement to conventional medical treatment has been proposed. In this sense, the use of Ocimum basilicum (OB) stands out, popularly known as basil and used to treat various metabolic disorders. Therefore, the objective of this work was to evaluate the antioxidant, anti-inflammatory and cytotoxic activity in vitro and perform the phytochemical characterization of the aqueous extract of OB. The evaluation of the antioxidant activity of the extract was based on the methods of scavenging the 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical, the β-carotene/linoleic acid system and an assay based on the absorption capacity of oxygenated radicals – ORAC . The cytotoxicity of the extracts was analyzed through the metabolic reduction of 3-[4,5 dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium (MTT) in fibroblast (L929) and macrophage (J774A) cell lines. The anti-inflammatory potential was evaluated by the ability to reduce the formation of nitric oxide (NO) and production of pro-inflammatory cytokines (IL-6, IL-12 and TNF-α) in stimulated macrophages. A phytochemical screening was carried out using the dosages of phenols and flavonoids (121.34 ± 8.40 mg of tannic acid Eq./g of sample and 6.17 ± 0.58 mg of quercetin Eq./g of sample, respectively), in addition to characterization using the UFLC-MS-Q-TOF technique, showing a prevalence of phenolic acids (acids: p-hydroxybenzoic, quinic, gallic, chicoric, chlorogenic, ferulic, caftaric and rosmarinic acids), followed by flavonoids (quercetin and rutin). The extract showed promising antioxidant activity, evidenced by reduced IC50 values (DPPH = 2.78 ± 0.61 µg/mL; ORAC = 10.03 ± 0.21 µg/mL). OB maintained the viability percentage of cell lines above 70%, as recommended by ISO 10993-5. In vitro anti-inflammatory activity showed a reduction in the concentration of NO (% reduction ~ 85%) and pro-inflammatory cytokines (% reduction IL-6 ~ 52%; IL 12 ~ 46%; TNF-α ~ 30%). In view of the results achieved, it is observed that the extract showed promising biological activity, which can be attributed to the content of phytoconstituents present in the sample, making it possible to continue investigations into subsequent therapeutic effects.