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.

Effects of liquid extract from Plinia cauliflora fruits residues on Chinese hamsters biochemical parameters

Plinia cauliflora (Mart.) Kausel, popularly known as jabuticaba, is rich in polyphenols. Phenolic compounds exhibit several biological properties, which reflect on biomarkers such as biochemical parameters. In the present study, we evaluated the plasmatic levels of glucose, total cholesterol, HDL-cholesterol, triglycerides, and uric acid of Chinese hamsters fed for 45 days with a regular diet or cholesterol-enriched diet supplemented with a liquid extract obtained from P. cauliflora fruits residues standardized in ellagic acid and total phenolic compounds. The results showed that the concentrated extract obtained from jabuticaba residues increased the glycemia of animals fed with a regular diet and reduced the plasmatic uric acid levels of animals fed with a cholesterol-enriched diet. Since hyperuricemia is considered to be a significant risk factor of metabolic disorders and the principal pathological basis of gout, the liquid extract from P. cauliflora fruits residues would be a promising candidate as a novel hypouricaemic agent for further investigation.

Study of the antibacterial capacity of extracts of Solanum incanum L., (Solanaceae) traditionally used for the management of avian cholera in rural areas of Burkina Faso

Nowadays, thanks to the rise of microbial resistance, the lack of health care personnel and especially the high cost of synthetic molecules, phytotherapy could be a panacea in many developing countries. For this reason, the present work which aims to evaluate the phenolic compounds and to study the antibacterial capacity of extracts of roots, stems, leaves and fruits of Solanum incanum L., (Solanaceae) traditionally used for the treatment of pasteurellosis or avian cholera in Burkina Faso, was undertaken. For this purpose, we collected plant material in the commune of Dedougou. After extraction with acetone and water, colorimetric tests were carried out on the different extracts and revealed mostly the presence of tannins and coumarins. The Hydroacetone macerated extract was found to be very interesting for biological activities compared to the macerated extracts and the aqueous decoctions. Inhibition of bacterial growth on different bacterial strains was also shown for all the extracts, especially with Hydroacetone extract. These results could be mainly explained by the inhibitory effect of phenolic compounds. The Hydroacetone extract was also found to be especially very relevant for the prevention and treatment of microbial diseases from poultry.

Influence of different preparation techniques on the composition and antioxidant action of curcumin and curcuminoids

Epidemiological evidence indicates that plant antioxidants activity can treat or help to prevent the development of various diseases. One species with great potential as an antioxidant is Curcuma longa. However, different extraction techniques can influence isolated chemical compounds. This study investigated chemical composition and antioxidant activity of two rhizome extracts of C. longa: hydroethanolic, obtained by exhaustion (HECLex); and dried by a spray dryer (HECLsd). The phytochemical composition was evaluated by GC/MS. Antioxidant activity was evaluated using DPPH and FRAP assays. Total phenolic compounds and soil analyses were performed. The main components of HECLex were ar-turmerone, γ-curcumene, α-turmerone, and β-sesquiphellandrene. The main components of HECLsd were 9,12,15-octadecatrienoic acid, 2,3-bis([trimethylsilyl]oxy)propyl ester, verrucarol, and 1-monolinoleoylglycerol trimethylsilyl ether. HECLsd had significantly higher levels of phenolic compounds and higher antioxidant capacity compared with HECLex. In conclusion, processes of the preparation of C. longa rhizomes alter the chemical components and consequently their biological activity.

Toxicity of isolated phenolic compounds from Acorus calamus L. to control Spodoptera litura (Lepidoptera: Noctuidae) under laboratory conditions

Background Spodoptera litura (Lepidoptera: Noctuidae), the tobacco cutworm, is an prominent agricultural pest. To reduce the use of chemical pesticides that cause health problems and that leave residue in the environment, some botanical pesticides have been developed. Our research aimed to evaluate the insecticidal efficacy of Acorus calamus L. extract for the control of S. litura under laboratory conditions. Results After 24 h of topical application, the A. calamus methanolic crude extract showed toxicity against secondary instar S. litura larvae (LD50 ~ 7.438 µg/larva). Chrysin (5,7-dihydroxy flavone), one of the isolated phenolic compounds, showed optimal control efficiency (LD50 ~ 2.752 µg/larva) and showed a reduction in carboxylesterase activities, which have detoxification reduction roles in larvae. Conclusion Chrysin in the crude extract of A. calamus may be an active compound to control this pest, and it may be applied as an alternative to minimize the usage of chemical insecticides. Graphical Abstract