Green nanotechnology has significant applications in various biomedical science fields. In this study, green-synthesized silver nanoparticles, prepared by using Catharanthus roseus and Azadirachta indica extracts, were characterized using UV–Vis spectroscopy, dynamic light scattering, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Silver nanoparticles (Ag NPs) synthesized from leaf extracts of C. roseus and A. indica effectively inhibited the growth of multidrug-resistant (MDR) bacteria isolated from patients with septic wound infections. The maximum bacteriolytic activity of the green-synthesized Ag NPs of C. roseus and A. indica against the MDR bacterium K. Pneumoniae was shown by a zone of inhibition of 19 and 16 mm, respectively. C. roseus Ag NPs exhibited more bacteriolytic activity than A. indica Ag NPs in terms of the zone of inhibition. Moreover, these particles were effective in healing wounds in BALB/c mice. Ag NPs of C. roseus and A. indica enhanced wound healing by 94% ± 1% and 87% ± 1%, respectively. Our data suggest that Ag NPs from C. roseus and A. indicia ameliorate excision wounds, and wound healing could be due to their effective antimicrobial activity against MDR bacteria. Hence, these Ag NPs could be potential therapeutic agents for the treatment of wounds.

Developing an efficient and cost-effective wound-healing substance to treat wounds and regenerate skin is desperately needed in the current world. Antioxidant substances are gaining interest in wound healing, and green-synthesized silver nanoparticles have drawn considerable attention in biomedical applications due to their efficient, cost-effective, and non-toxic nature. The present study evaluated in vivo wound healing and antioxidant activities of silver nanoparticles from Azadirachta indica (AAgNPs) and Catharanthus roseus (CAgNPs) leaf extracts in BALB/c mice. We found rapid wound healing, higher collagen deposition, and increased DNA and protein content in AAgNPs- and CAgNPs (1% w/w)-treated wounds than in control and vehicle control wounds. Skin antioxidant enzyme activities (SOD, catalase, GPx, GR) were significantly (p < 0.05) increased after 11 days CAgNPs and AAgNPs treatment. Furthermore, the topical application of CAgNPs and AAgNPs tends to suppress lipid peroxidation in wounded skin samples. Histopathological images evidenced decreased scar width, epithelium restoration, fine collagen deposition, and fewer inflammatory cells in CAgNPs and AAgNPs applied wounds. In vitro, the free radical scavenging activity of CAgNPs and AAgNPs was demonstrated by DPPH and ABTS radical scavenging assays. Our findings suggest that silver nanoparticles prepared from C. roseus and A. indica leaf extracts increased antioxidant status and improved the wound-healing process in mice. Therefore, these silver nanoparticles could be potential natural antioxidants to treat wounds.

Ultraviolet B (UVB) radiation is a primary cause of DNA damage in the skin, which is often a precursor to skin cancer. Natural products represent a rich source of compounds with unexplored photoprotective properties. Our previous work identified 3-methoxybenzyl isothiocyanate (MBITC), a meadowfoam derivative, as a promising UVB-absorptive agent that reduces DNA damage and cell proliferation; however, its clinical use is limited by dose-dependent cytotoxicity. To address this, we synthesized a novel amide lipid conjugate of MBITC, N-(3-methoxybenzyl)eicos-5-enamide (MBA), and evaluated its photoprotective efficacy and mechanism of action. Our findings demonstrate that MBA exhibited remarkably reduced cytotoxicity compared to its parent compound, while effectively retaining its photoprotective properties. In human primary keratinocyte cultures, MBA significantly reduced UVB-induced DNA damage, as evidenced by a decrease in cyclobutane pyrimidine dimers (p < 0.05) and γ-H2A.X (p < 0.05). Furthermore, MBA increased the expression of DNA damage response (DDR) proteins and DNA damage-binding protein 1 (DDB1) (p < 0.05) and the activation of Ataxia Telangiectasia and Rad3-related protein (ATR) (p < 0.05), a master regulator of DDR and repair pathways. These findings suggest that MBA acts through direct UVB absorption and/or the engagement of DDR pathways following irradiation, highlighting its potential use as a novel photoprotective compound.