The essential oils of Grewia Lasiocarpa E. Mey. Ex Harv.: chemical composition, in vitro biological activity and cytotoxic effect on Hela cells.

The chemical composition and biological activity of the essential oil extracted from the fresh leaves and stem bark of Grewia lasiocarpa was determined for the first time in this study. The essential oils were extracted by hydrodistillation and identified by GC-MS and FTIR. The antibacterial, antioxidant activity and total phenolic content of essential oils were determined. The major compounds identified were phytol (22.6%); α-farnesene (8.62%); n-hexadecanoic acid (7.24%); farnesol (4.61%) in the leaves, and 2-methylheptadecane (7.24%); heptacosane (7.60%); heptadecane, 2,6,10,14-tetramethyl (7.30%). The presence of aromatic, alkanes and phenolic compounds were revealed by FTIR analysis. The in silico oral prediction shows that some of the components are orally safe. The essential oil from the leaves showed cytotoxic activity at 1mg/mL(IC50 =555.70 µg/mL) against HeLa cells. The oils exhibited no significant antioxidant activity (IC50 >1 000 µg/mL) with <100 mg/g GAE of total phenol. The essential oils showed different degrees of activities against Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Klebsiella pneumoniae (ATCC 314588) at 10 µg/mL, 5 µg/mL and 2.5 µg/mL. These results might provide a future reference basis for further exploration of more of its medicinal application.

Amino Acid Functionalized Hydrotalcites for Gene Silencing.

Hydrotalcites and amino acid functionalized hydrotalcites (aa-HTs) were synthesized using the co-precipitation method. These compounds were characterized using X-ray diffraction (XRD), inductively coupled plasma-optical emission spectroscopy (ICP-OES), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and nanoparticle tracking analysis (NTA). The optimal siRNA binding capacity was determined using gel retardation assays. Cytotoxicity studies using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the siRNA:HT complexes were relatively non-cytotoxic to HeLa-tat-luc cells. Gene silencing studies showed that the aa-HTs elicited significantly higher levels of gene knockdown when compared to the non-functionalized HTs. Overall, these HTs have shown the potential to bind, protect and efficiently deliver siRNA, in vitro.