Phytochemical characterization, antioxidant potential and antibacterial activity of the Croton argyrophylloides Muell. Arg. (Euphorbiaceae)

Croton argyrophylloides Muell. Arg., from the Euphorbiaceae family, popularly known as marmeleiro prateado or sacatinga, is a plant from the Caatinga biome commonly found in Brazil’s northeastern region. The present study aimed to evaluate the antioxidant activity of the species. The phytochemical study was performed through qualitative analysis of chemical constituents and quantitative determination of the total phenol content through the Folin-Ciocalteu test. The qualitative and quantitative antioxidant tests were performed using the DPPH method (2.2 diphenyl-1-picryl hydrazil) and ferric reducing antioxidant power (FRAP). The minimum inhibitory concentration (MIC) was determined by microdilution in 96-well plates. The ethanolic extract of the leaves of C. argyrophylloides manifested antioxidant action in the quantitative DPPH test with a significant bioactivity of 84.70 AAO% in 500 µg/mL, with an EC50 of 236.79. The content of total phenolic compounds was 946.06 mg of gallic acid equivalents/g of sample, and total flavonoids was 58.11 mg of quercetin equivalents/g of sample, the result obtained for FRAP was 15294.44 µM Trolox/g of sample and ABTS was 718 μM Trolox of sample. The prospecting of the chemical constituents of the leaves of C. argyrophylloides revealed the presence of the main compounds that manifests the antioxidant activity and it was proven by the DPPH method that there is antioxidant activity in the analyzed sample, in addition to demonstrating a significant content of phenolic compounds and total flavonoid content in the species, which corroborates the antioxidant activity of the plant sample. The leaf extracts presented growth inhibition halos of 10 and 12 mm upon Staphylococcus aureus ATCC 25923.

Bioactive properties of Persea lingue Ness (Lauraceae) fruit and leaf extracts

Persea lingue Ness is a tree species that lives mainly in temperate forests of south-central Chile. Its leaves are used in ethnomedicine, the fruit is a drupe similar to that of the avocado and has not been studied. The aim of this study was to determine the cytotoxicity in leukemia cell and antibacterial activity, along with some chemical content characteristics of P. lingue fruit and leaf extracts. The antibacterial activity was determined by the inhibition of bacterial growth in liquid medium assay against Gram-positive and Gram-negative bacteria. The leukemia cell lines Kasumi-1 and Jurkat were used to evaluate the cytotoxic activity by using propidium iodide and AlamarBlue assays. Total phenolic, flavonoid, condensed tannin, alkaloid and lipid contents were evaluated in the fruit and in the leaf extracts. The antioxidant activity of both extracts were also elavaluated. Leaf extract presented the highest content of total phenols, condensed tannins and flavonoids, and also the highest antioxidant activity. While the fruit extract has a higher amount of lipids and alkaloids and the high antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus megaterium and Micrococcus luteus. The leaf extract only showed activity against M. luteus. Concerning the cytotoxic activity, only the fruit extract showed cytotoxicity against the cell lines Jurkat and Kasumi-1. P. lingue fruit extract is a potential source of biologically active molecules for the development of new drugs to be used in some types of leukemia, as well as antibacterial agent.

Comparative Study of the Antioxidant Activity of the Plasma of Healthy Subjects and those with Uterine Myomas by Scavenging the ABTS Radical+

Introduction: The oxidative stress and the deterioration of the antioxidant system demonstrated by the dosage of antioxidant enzymes and the by-products of lipid peroxidation are involved in the occurrence of uterine myomas. Objectives: To measure the antioxidant activity of the plasma of patients with uterine myoma and that of the plasma of their age-matched controls by trapping the free radical ABTS+. The study aims to confirm by another assessment technique. Results: The anti-free radical activities of the plasmas of patients with myomas and those of their respective controls vary from 1.3 to 6%. In addition, two cases were observed: either the anti-radical activity of the control subjects turned out to be slightly higher than that of the patients; or the anti-free radical activity of patients with uterine myomas was slightly stronger than those of their controls. In addition, our results showed that the anti-free radical activity of patients aged over 40 years is slightly higher than that of patients aged less than or equal to 40 years. Finally, the anti-free radical activity decreases with an increase in BMI and increases with the number of gestities and parity. Conclusion: Assessment of the total antioxidant capacity of blood by trapping the ABTS+ radical can be used to assess, at a certain threshold, the oxidative stress involved in the development of uterine myoma. This method can also be used to assess the effect of age, BMI, pregnancy and parity on the occurrence of myomas.