Cytotoxic, antioxidant, and antiglycation activities, and tyrosinase inhibition using silver nanoparticles synthesized by leaf extract of Solanum aculeatissimum Jacq.

The present study aimed to determine the biological properties of an extract of Solanum aculeatissimum aqueous extract (SaCE) alone as well as silver nanoparticles (AgNPs) generated by green synthesis utilizing S. aculeatissimum aqueous extract (SaCE). These synthesized SaCE AgNPs were characterized using UV-VIS spectrophotometry, scanning transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), zeta potential (ZP), dynamic light scattering (DLS). Determination of total polyphenols, flavonoids, saponins content was conducted. In addition, high performance liquid chromatography-mass spectrometry (HPLC-MS) was employed to identify constituents in this extract. Antioxidant activity was determined by DPPH radical scavenging and ferric ion reducing power (FRAP) methods. Antiglycation activity was demonstrated through relative mobility in electrophoresis (RME) and determination of free amino groups. The inhibitory activity on tyrosinase was also examined. Molecular docking analyses were performed to assess the molecular interactions with DNA and tyrosinase. The antitumor activity SaCE was also measured. Phytochemical analysis of SaCE and AgNPs showed presence polyphenols (1000.41 and 293.37 mg gallic acid equivalent/g), flavonoids (954.87 and 479.87 mg rutin equivalent/g), saponins (37.89 and 23.01% total saponins), in particular steroidal saponins (aculeatiside A and B). Both SaCE and AgNPs exhibited significant antioxidant (respectively, 73.97%, 56.27% in DPPH test, 874.67 and 837.67 µM Trolox Equivalent/g in FRAP test) and antiglycation activities (72.81 and 67.98% free amino groups, results observed in RME). SaCE and AgNPs presented 33.2, 36.1% inhibitory activity on tyrosinase, respectively. In silico assay demonstrated interaction between steroidal saponins, DNA or tyrosinase. SaCE exhibited antitumor action against various human tumor cells. Data demonstrated that extracts SaCE alone and AgNPs synthesized from SaCE presented biological properties of interest for application in new therapeutic formulations in medicine.

Evaluation of curcumin nanoemulsion effect to prevent intestinal damage.

Curcumin has gained great prominence for the prevention and treatment of inflammatory bowel disease. However, studies have reported the low bioavailability of orally administered curcumin. This work aimed to evaluate the characteristics, stability and effects of a curcumin-carrying nanoemulsion in preventing intestinal damage induced by indomethacin. Nanoemulsions containing curcumin were prepared by spontaneous emulsification method and it was characterized by dynamic light scattering (DLS), zeta potential and the morphology was evaluated by scanning electron microscopy (SEM). Its stability was tested under different conditions of pH, temperature at 0, 7, 14, 21 and 28 days. In animal experimentation, 36 male mice of the Mus musculus lineage (C57BL/6) were used. The intestinal inflammation was evaluated based on macroscopic, histopathological and metagenomic analysis. It was found a stable nanoemulsion with a size of 409.8 nm, polydispersion index (PDI) of 0.132 and zeta potential of -18.8 mV. However, these lost charge in pH2, showing instability in acidic media (p < 0.05). In animal experiments, the nanoemulsion did not significantly improve intestinal inflammation. However, the group treated with curcumin nanoemulsion showed a higher relative abundance of the genus Lactobacillus (p < 0.05). In conclusion, the curcumin nanoemulsion was relevant in the modulation of the intestinal microbiota.