Estudo químico e avaliação das atividades biológicas de Erythroxylum nummularium Peyr espécie vegetal endêmica do Brasil

Abstract

Erythroxylum nummularium Peyr is a plant species found exclusively in Brazil that has bioactive substances such as epicatechin, quercetin, β-amyrin, lupeol, erythrodiol palmitate and β-sitosterol. These substances have anti-inflammatory, antioxidant, analgesic, antidiabetic, anticancer, antimicrobial, anti-toxoplasmosis and hepatoprotective action. This study aimed to expand the knowledge about the chemical composition and biological activities of different plant organs, including leaves, branches, stem bark and stem, from methanol extracts and organic fractions obtained by partitioning in solvents of increasing polarities (hexane, dichloromethane, ethyl acetate and butanol). The extracts and fractions were analyzed for phenolics, flavonoids and total alkaloid content, as well as evaluated in antioxidant activity assays (DPPH, β-carotene/linolenic acid and phosphomolybdate), antimicrobial activity (against Staphylococcus aureus, Streptococcus mutans and Streptococcus sobrinus), antinociceptive (in vivo) and toxicity (using Artemia salina and an animal model with mice). The phytochemical screening was performed by thin layer chromatography (CCD) and the chemical composition was characterized by gas chromatography coupled to mass spectrometry (GC-MS). In the antinociceptive assay, the ethyl acetate fraction of the leaves (ELEN) was administered orally to male Balb-C mice at doses of 6.25, 12.5, 25 and 50 mg/kg. After 60 minutes, the animals received 0.6% acetic acid intraperitoneally, and the number of abdominal contortions was recorded. The results indicated significant levels of phenolics and total flavonoids, as well as lower concentrations of alkaloids. CCD revealed the presence of saponins, tannins, and steroids, while GC-EM analysis identified glycerol, hexadecanoic acid, methyl hexadecanoate, and lupeol acetate as the main substances. Among the antioxidant assays, the ethyl acetate fractions of the leaves, twigs and bark of the stem stood out for the most expressive results. In the antimicrobial test, the ethyl acetate and dichloromethane fractions of the leaves showed efficacy against S.aureus, while the hexane and butanolic fractions exhibited activity against S.mutans. No specimens were active against S.sobrinus. The toxicity test on A.salina revealed moderate to high toxicity for crude extracts and organic fractions, except for the ELEN fraction, which was considered non-toxic. The antinociceptive activity of this fraction was more pronounced at a dose of 6.25 mg/kg, significantly reducing abdominal contortions, with no signs of toxicity in mice after 15 days of analysis with doses up to 2000 mg/kg. These results indicate that E.nummularium is a promising source of bioactive substances, with potential for the development of new drugs.