Biological screening of extracts from leaf and stem bark of Croton floribundus Spreng. (Euphorbiaceae)

Abstract

This work describes the preliminary evaluation of cytotoxic, antimicrobial, molluscicidal, antioxidant and anticholinesterase activities from leaf (LECF) and stem bark alcoholic extracts (BECF) of the species Croton floribundus Spreng. (Euphorbiaceae), popularly known as capixingui or tapixingui. BECF presented significant toxicity (LC50 = 89.6 μg/ml) in the Artemia salina Leach, 1819 (Crustacea: Branchiopoda) bioassay, whereas LECF did not show activity (LC50 > 1000 μg/ml). From DPPH method, the values of IC50 for the LECF and BECF were 61.2 μg/ml and 62.2 μg/ml, respectively, showing that C. floribundus has an expressive antioxidant activity. Antimicrobial susceptibility was evaluated by microdilution technique and only BECF was active against Staphylococcus aureus (MIC = 39.6 μg/ml). The extracts did not present molluscicidal activity against snail Biomphalaria glabrata Say, 1818 (Gastropoda: Planorbidae). Both extracts revealed the presence of several components with an inhibiting capacity of acetylcholinesterase enzyme on the bioautographic assay. C. floribundus showed to be a promising species considering that it exhibited good biological activity in the most assays performed.

Triagem toxicológica de extratos de Pimenta pseudocaryophyllum (Gomes) L.R. Landrum frente à Artemia salina Leach

“…Confirmando-se esta maior toxicidade pelo menor valor de CL 50 (p < 0,01) apresentado pelo extrato Ppf durante exposição por 48hs, quando comparado a 24hs (Tabela 1), sendo considerada uma alta toxicidade (CL 50 < 100 µg/mL). O fato da significante toxicidade observada pelo extrato Ppf, deve ser considerada como uma característica interessante para utilizar este extrato vegetal para futuros estudos de citotoxicidade 24 . Assim, sugere-se que as folhas P. pseudocaryophyllum também possuem metabólitos ativos que levam toxicidade a artemia, que parecem ser diferentes daqueles encontrados no caule, ou estão de alguma maneira mais concentrados nas folhas.…”

Toxicity and phytochemistry of eight species used in the traditional medicine of sul-mato-grossense, Brazil

“…In a complementary manner, by associating the chemical profile of eight plants with the corresponding LC 50 obtained against Brine shirmp, that can be correlated with other biological activities (Barth et al, 2018), it was observed that among species with higher diversity and predominance of flavonoids and phenolic compounds, with higher LC 50 values are the extract of A. humile, G. americana, B. dracunculifolia, C. adamantium McLaughlin et al (1993), which has low toxicity (LC 50 greater than 500 µg mL -1 ); moderate (between 100 and 500 µg mL -1 ) and very toxic (below 100 µg mL -1 ).…”

Biological activity survey of Pereskia aculeata Mill. and Pereskia grandifolia Haw. (Cactaceae)

“…The scavenging activity of Pereskia extracts (PAF, PAL, PGF, PGL) on DPPH radicals was determined according to a modified Blois method. 21 Aliquots (0.1 ml) of each extract at a range concentration (62.5, 125, 250, 500, 1000, 2000 μg/ml) were mixed with a DPPH (Sigma-Aldrich®) solution in methanol (2.9 ml at 60 μM) and kept in the dark for 30 minutes. After the incubation period, the absorbance values were measured with a spectrophotometer (Femto, 700 plus model; Brazil) at 517 nm.…”

“…The anticholinesterase activity of the Pereskia extracts (PAF, PAL, PGF, PGL) was assessed by means of a bioautographic assay 25 as previously described. 21 The acetylcholinesterase enzyme (AChE; Sigma-Aldrich®) was dissolved in a tris-hydrochloric acid buffer (0.05 M, pH 7.8) with bovine serum albumin (1 mg/ml, 98%, Sigma-Aldrich®) and stored at 4°C. Aliquots of different volumes (equivalent to 600, 400, 200, 150, 100, 50 and 25 μg dry mass) of each extract stock solution were loaded on TLC F 254 plates (10 x 10 cm, 0.2 mm thickness; Merck®).…”