In vitro antioxidant and ex vivo anti-cataract activity of ethanolic extract of Cineraria maritima: a traditional plant from Nilgiri hills

Green Synthesis of Silver Nanoparticles Using Jacobaea maritima and the Evaluation of Their Antibacterial and Anticancer Activities

Much attention has been gained on green silver nanoparticles (green-AgNPs) in the medical field due to their remarkable effects against multi-drug resistant (MDR) microorganisms and targeted cancer treatment. In the current study, we demonstrated a simple and environment-friendly (i.e., green) AgNP synthesis utilizing Jacobaea maritima aqueous leaf extract. This leaf is well-known for its medicinal properties and acts as a reducing and stabilizing agent. Nanoparticle preparation with the desired size and shape was controlled by distinct parameters; for instance, temperature, extract concentration of salt, and pH. The characterization of biosynthesized AgNPs was performed by the UV-spectroscopy technique, dynamic light scattering, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared. The successful formation of AgNPs was confirmed by a surface plasmon resonance at 422 nm using UV-visible spectroscopy and color change observation with a particle size of 37± 10 nm and a zeta potential of -10.9 ± 2.3 mV. SEM further confirmed the spherical size and shape of AgNPs with a size varying from 28 to 52 nm. Antibacterial activity of the AgNPs was confirmed against all Gram-negative and Gram-positive bacterial reference and MDR strains that were used in different inhibitory rates, and the highest effect was on the E-coli reference strain (MIC = 25 μg/mL). The anticancer study of AgNPs exhibited an IC50 of 1.37 μg/mL and 1.98 μg/mL against MCF-7 (breast cancer cells) and A549 (lung cancer cells), respectively. Therefore, this green synthesis of AgNPs could have a potential clinical application, and further in vivo study is required to assess their safety and efficacy.

Natural Antioxidant Activities of Plants in Preventing Cataractogenesis

A cataract is a condition that causes 17 million people to experience blindness and is the most significant cause of vision loss, around 47.9%. The formation of cataracts is linked to both the production of reactive oxygen species (ROS) and the reduction of endogenous antioxidants. ROS are highly reactive molecules produced by oxygen. Examples of ROS include peroxides, super-oxides, and hydroxyl radicals. ROS are produced in cellular responses to xenobiotics and bacterial invasion and during mitochondrial oxidative metabolism. Excessive ROS can trigger oxidative stress that initiates the progression of eye lens opacities. ROS and other free radicals are highly reactive molecules because their outer orbitals have one or more unpaired electrons and can be neutralized by electron-donating compounds, such as antioxidants. Examples of natural antioxidant compounds are vitamin C, vitamin E, and beta-carotene. Numerous studies have demonstrated that plants contain numerous antioxidant compounds that can be used as cataract preventatives or inhibitors. Natural antioxidant extracts for cataract therapy may be investigated further in light of these findings, which show that consuming a sufficient amount of antioxidant-rich plants is an excellent approach to cataract prevention. Several other natural compounds also prevent cataracts by inhibiting aldose reductase and preventing apoptosis of the eye lens.