Biosorption process using Cereus jamacaru DC, Cactaceae for Pb2+ removal from aqueous systems.

Lead is a highly toxic metal associated with many human health diseases that can be caused by several environmental changes. Innovative sustainable solutions for water remediation have been recently encouraged by using renewable, low-cost and earth-abundant biomass materials to ensure public health conditions. In this article, Cereus jamacaru DC (popularly known as Mandacaru) was investigated as a biosorbent in the Pb2+ removal from aqueous solution using a two-level factorial design. The analysis of variance suggested a significant and predictive model (R2 = 0.9037). The maximum efficacy of Pb2+ removal in the experimental design was 97.26%, being the optimized conditions: pH 5.0, contact time 4 h without adding NaCl. The Mandacaru was divided into three types according to the plant structure and this parameter did not present a significant interference in the biosorption process. This result corroborates with slight differences in the total soluble proteins, carbohydrates and phenolic compounds found in the Mandacaru types investigated. FT-IR analysis revealed the presence of O-H, C-O and C = O groups that were responsible for the ion biosorption process. The optimized procedure was capable to remove 97.28% of the Pb2+ added in the Taborda river water sample. The kinetic adsorption results show the pseudo-second-order model, suggesting chemisorption process. Thus the treated water sample can be considered in accordance with technical standards issued by CONAMA Resolution Num. 430/2011 and Ordinance GM/MS Num.888/2021 of WHO. In this way, the Mandacaru proved to be an efficient, fast and easy-to-apply bioadsorbent in Pb2+ removal and has great environmental application potential.

Tephrosia toxicaria (Sw.) Pers. extracts: Screening by examining aedicidal action under laboratory and field conditions along with its antioxidant, antileishmanial, and antimicrobial activities.

An increase in the incidence of arboviral, microbial and parasitic infections, and to disorders related to oxidative stress has encouraged the development of adjuvant therapies based on natural formulations, such as those involving plant extracts. Thus, to expand the repertoire of the available therapeutic options, this study aimed to describe the versatility of Tephrosia toxicaria (Sw.) (Pers., 1807) extracts for the control of arbovirus vectors, as well as their antioxidant, antileishmanial, and antimicrobial potential. Among the aqueous and hydroethanolic extracts obtained, the hydroethanolic extract from roots (RHA) was identified as the most active larvicide extract demonstrating, respectively, the lowest lethal concentration (mg/mL) for 50%, 90% and 99% of Aedes aegypti (L., 1762) and Aedes albopictus (S., 1894) larvae, observed at 24 h (0.33, 0.84 and 1.80; 0.32, 0.70 and 1.32) and 48 h (0.17, 0.51 and 1.22; 0.26, 0.47 and 0.78) post-exposure. Field assays revealed that RHA (0.84 mg/mL) is a potential oviposition deterrent, reducing egg-laying by approximately 90%. RHA (0.1 mg/mL) also exhibited antioxidant activity for the following tests: total antioxidant capacity (286.86 mg AAE/g), iron (87.16%) and copper (25.64%) chelation, and superoxide scavenging (10%). In the cell culture assays, RHA (0.1 mg/mL) promoted regeneration of metabolic activity (92% cell viability) in cells exposed to oxidative stress. Furthermore, RHA displayed weak antileishmanial activity (IC50 = 3.53 mg/mL) against Leishmania amazonensis and not exhibit antimicrobial activity. The extraction favored the concentration of carbohydrates in RHA, in addition to lectins and protease inhibitors, with molecular masses estimated between 10 and 24 kDa. Cytotoxicity and phytotoxicity analyses of RHA suggested its biosecurity. Thus, RHA is a multivalent extract with insecticide and antioxidant properties at low and safe concentrations. However, others studies on its indirect toxic effects are ongoing to ensure the complete safety of RHA.