Therapeutic potential of biogenic and optimized silver nanoparticles using Rubia cordifolia L. leaf extract.

Rubia cordifolia L. is a widely used traditional medicine in the Indian sub-continent and Eastern Asia. In the present study, the aqueous leaf extract of the R. Cordifolia was used to fabricate silver nanoparticles (RC@AgNPs), following a green synthesis approach. Effect of temperature (60 °C), pH (8), as well the concentration of leaf extract (2 ml) and silver nitrate (2 mM) were optimized for the synthesis of stable RC@AgNPs. The phytofabrication of nanosilver was validated by UV-visible spectral analysis, which displayed a distinctive surface plasmon resonance peak at 432 nm. The effective functional molecules as capping and stabilizing agents, and responsible for the conversion of Ag+ to nanosilver (Ag0) were identified using the FTIR spectra. The spherical RC@AgNPs with an average size of ~ 20.98 nm, crystalline nature, and 61% elemental composition were revealed by TEM, SEM, XRD, and. EDX. Biogenic RC@AgNPs displayed a remarkable anticancer activity against B16F10 (melanoma) and A431 (carcinoma) cell lines with respective IC50 of 36.63 and 54.09 µg/mL, respectively. Besides, RC@AgNPs showed strong antifungal activity against aflatoxigenic Aspergillus flavus, DNA-binding properties, and DPPH and ABTS free radical inhibition. The presented research provides a potential therapeutic agent to be utilized in various biomedical applications.

Cytotoxic, Antimitotic, DNA Binding, Photocatalytic, H2O2 Sensing, and Antioxidant Properties of Biofabricated Silver Nanoparticles Using Leaf Extract of Bryophyllum pinnatum (Lam.) Oken.

Bryophyllum pinnatum is a perennial herb traditionally used in ethnomedicine. In the present report, silver nanoparticles (AgNPs) were synthesized using B. pinnatum leaf extract. BP-AgNPs were confirmed following UV-Vis spectroscopy with SPR peak at 412 nm and further characterized by FTIR, XRD, SEM-EDX, and TEM. Microscopic images confirmed the spherical shape and ~15 nm average size of nanostructures. BP-AgNPs were evaluated for photocatalytic degradation of hazardous dyes (methylene blue and Rhodamine-B) and showed their complete reduction within 100 and 110 min., respectively. BP-AgNPs have emerged as a unique SPR-based novel sensor for the detection of H2O2, which may deliver exciting prospects in clinical and industrial areas. DPPH and ABTS free radical scavenging activity were studied with respective IC50 values of 89 and 259 µg/mL. A strong intercalating interaction of CT-DNA with BP-AgNPs was investigated. Observed chromosomal abnormalities confirm the antimitotic potential of BP-AgNPs in the meristematic root tip. The cytotoxicity of BP-AgNPs against B16F10 (melanoma cell line) and A431 (squamous cell carcinoma cell line), was assessed with respective IC50 values of 59.5 and 96.61 µg/ml after 24 h of treatment. The presented green synthetic approach provides a novel and new door for environmental, industrial, and biomedical applications.

DNA-binding, antioxidant, H2O2 sensing and photocatalytic properties of biogenic silver nanoparticles using Ageratum conyzoides L. leaf extract.

Green nanotechnology is gaining widespread interest owing to the elimination of harmful reagents and offers a cost-effective synthesis of expected products. In the present study, silver nanoparticles (AgNPs) were synthesized from Ageratum conyzoides leaf extract (ACLE). UV-visible spectrophotometry showing a characteristic SPR peak at 443 nm verified the phytosynthesis of AC-AgNPs. The FTIR spectrum was examined to identify the efficient functional molecules responsible for the reduction of Ag+ to metallic silver (Ag0). SEM, TEM and XRD illustrated the formation of crystalline and spherical NPs with a size range of 14-48 nm. EDX data showed the presence of elemental silver with an energy peak at 3 eV. CT-DNA interaction with AC-AgNPs was investigated and the UV absorption spectra revealed a bathochromic effect indicating groove binding. AC-AgNPs showed a strong antioxidant property in a concentration-dependent manner when analyzed by DPPH and ABTS radical scavenging assay. AC-AgNPs were investigated as a SPR-based H2O2 sensor, which can provide promising opportunities in medical and environmental fields to detect reactive oxygen species such as H2O2. The catalytic effectiveness of phytosynthesized NPs was also examined within 2 h of exposure for methylene blue degradation under sunlight. There is thus a reasonable potential application of green synthesized AC-AgNPs for the degradation of hazardous synthetic dyes.