Greener approach for the isolation of oleanolic acid from Nepeta leucophylla Benth. Its derivatization and their molecular docking as antibacterial and antiviral agents

Evaluation of Cytotoxic and Antioxidant Potential of Green-Synthesized Silver and Gold Nanoparticles From Nepeta leucophylla Benth

In the present study, silver (AgNPs) and gold (AuNPs) nanoparticles (NPs) have been prepared using the ethanolic extract of Nepeta leucophylla (NLe). This plant was considered owing to its richness in natural polyphenols and antioxidants that are well known for their reducing potential. Different techniques, such as UV (ultraviolet-visible spectrophotometer), FTIR (Fourier transform infrared radiation), and XRD (X-ray diffraction), were utilized for the characterization of NPs. The UV absorption peak was observed at 434 and 535 nm for NLe-AgNPs and NLe-AuNPs, respectively. FTIR suggested about the possible classes of biomolecules involved in the formation of metal NPs. XRD pattern confirmed the crystalline structure of gold and silver NPs and validated that the crystal structure under consideration is a face-centered cubic (FCC) pattern. High-resolution transmission electron microscopy (HR-TEM) images revealed that the NLe-AgNPs and NLe-AuNPs NPs were spherical in shape, with average diameter of 11.4 and 7.8 nm, respectively. The antioxidant potential was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, which revealed that NLe exhibited the highest antioxidant potential (79.37%) compared to synthesized metal NPs. Further, cytotoxic potential was evaluated using MTT assay against Hep G2 cell lines. The IC50 values were determined to be 5.97 µg/mL for NLe, 12.31 µg/mL for NLe-AgNPs, and 34.58 µg/mL for NLe-AuNPs, demonstrating their effectiveness in inhibiting cancer cell proliferation. The present results revealed that NLe may play a promising role in the cure of different deteriorative diseases. In future, more detailed studies based on animal model may be useful to support the present results and to evaluate further health benefits of NLe.

Evaluation of the antiviral activity of oleanolic acid against nervous necrosis virus

Viral nervous necrosis (VNN) presents a significant challenge to aquaculture due to its potential for causing mass fish mortality and resulting in substantial economic losses. Therefore, the urgent need to find antiviral drugs is paramount. This study found that oleanolic acid (OA) exhibited anti-nervous necrosis virus (NNV) activity both in vivo and in vitro. The RT-qPCR results demonstrated that OA at 10.95 μM had an inhibition rate of 99.97 %. The prevention experiments also showed that OA pretreatment effectively inhibited the replication of NNV. Furthermore, the results of indirect immunofluorescence and flow cytometry suggest that OA's anti-NNV effect may be due to its ability to inhibit NNV-induced apoptosis. The in vivo study revealed a 30 % survival rate in the OA treatment group, compared to only 10 % in the control group. Additionally, RT-qPCR results demonstrated that OA treatment upregulated immune gene expression in grouper and effectively suppressed NNV replication in the host. This study demonstrates the potential of OA as an antiviral therapeutic agent for NNV. It exerts its antiviral effect by upregulating immune gene expression. These findings provide valuable insights into the development of novel antiviral treatment strategies.

Chenopodium quinoa Willd. and Amaranthus hybridus L.: Ancestral Andean Food Security and Modern Anticancer and Antimicrobial Activity

The species Chenopodium quinoa Willd. and Amaranthus hybridus L. are Andean staples, part of the traditional diet and gastronomy of the people of the highlands of Colombia, Ecuador, Peru, Bolivia, northern Argentina and Chile, with several ethnopharmacological uses, among them anticancer applications. This review aims to present updated information on the nutritional composition, phytochemistry, and antimicrobial and anticancer activity of Quinoa and Amaranth. Both species contribute to food security due to their essential amino acid contents, which are higher than those of most staples. It is highlighted that the biological activity, especially the antimicrobial activity in C. quinoa, and the anticancer activity in both species is related to the presence of phytochemicals present mostly in leaves and seeds. The biological activity of both species is consistent with their phytochemical composition, with phenolic acids, flavonoids, carotenoids, alkaloids, terpenoids, saponins and peptides being the main compound families of interest. Extracts of different plant organs of both species and peptide fractions have shown in vitro and, to a lesser degree, in vivo activity against a variety of bacteria and cancer cell lines. These findings confirm the antimicrobial and anticancer activity of both species, C. quinoa having more reported activity than A. hybridus through different compounds and mechanisms.