Anticancer and antimicrobial activity of biosynthesized Red Sea marine algal silver nanoparticles

Abstract

Biosynthesis of silver nanoparticles (AgNPs) is emerging as a simple and eco-friendly alternative to conventional chemical synthesis methods. The role of AgNPs is expanding as antimicrobial and anticancer agents, sensors, nanoelectronic devices, and imaging contrast agents. In this study, biogenic AgNPs were synthesized using extracts of different marine algae species, including Ulva rigida (green alga), Cystoseira myrica (brown alga), and Gracilaria foliifera (red alga), as reducing and capping agents. The Physiochemical properties, cytotoxicity, anticancer and antimicrobial activities of the biosynthesized AgNPs were assessed. Surface plasmonic bands of the biosynthesized AgNPs capped with U. rigida, C. myrica, and G. foliifera extracts were visually observed to determine a colour change, and their peaks were observed at 424 nm, 409 nm, and 415 nm, respectively, by UV–Vis spectroscopy; transmission electron microscopy (TEM) indicated an almost spherical shape of AgNPs with nanoscale sizes of 12 nm, 17 nm, and 24 nm, respectively. Fourier transform-infrared (FTIR) spectroscopy analysis suggested that different molecules attached to AgNPs through OH, C=O, and amide groups. The major constituents of the aqueous algal extracts included, terpenoids, polyphenols, sulfonates, polysaccharides, fatty acids, chlorophylls, amide proteins, flavonoids, carotenoids, aliphatic fluoro compounds, volatile compounds, alkalines, pyruvic acid and agar groups. The cytotoxicity and anticancer activities of the biosynthesized AgNPs were assessed using Artemia salina nauplii, normal skin cell lines (HFb-4), and breast cancer cell lines (MCF-7 cell line). The lethality was found to be directly proportional to the AgNP concentration. The IC50 values of C. myrica and G. foliifera AgNPs against A. saline nauplii were 5 and 10 μg ml−1 after 4 h and 16 h, respectively, whereas U. rigida AgNPs did not exhibit cytotoxic effects. Anticancer activity of the biosynthesized AgNPs was dose dependent. The IC50 values of the biosynthesized AgNPs were 13, 13, and 43 µg ml−1 for U. rigida, C. myrica, and G. foliifera, respectively. U. rigida AgNPs particularly exhibited potent anticancer activity (92.62%) against a human breast adenocarcinoma cell line (MCF-7) with high selectivity compared the normal cells (IC50 = 13 µg/ml, SI = 3.2), followed by C. myrica AgNPs (IC50 = 13 µg/ml, SI = 3.07). Furthermore, the biosynthesized AgNPs exhibited strong antifungal activity against dermatophyte pathogenic moulds and mild antibacterial activity against the food borne pathogen bacteria. The highest antimicrobial activity was recorded for the U. rigida AgNPs, followed by those capped with C. myrica and G. foliifera extracts, respectively. AgNPs capped with the U. rigida extract exhibited the highest antimicrobial activity against Trichophyton mantigrophytes (40 mm), followed by Trichosporon cataneum (30 mm) and E. coli (19 mm), with minimal lethal concentration of 32 and 64 μg ml−1 respectively. The study finally revealed that extracts of marine algal species, particularly U. rigida extracts, could be effectively used as reducing agents for the green synthesis of AgNPs. These AgNPs are considered efficient alternative antidermatophytes for skin infections and anticancer agents against the MCF-7 cell line.

Effect of Biologically and Chemically Synthesized AgNPs on Multi-Drug Resistant (MDR) Dermatophyte Bacterial Isolates

“…Compatible with these results, Alsharif et al (2020) reported that chemically and biosynthesized AgNPs exerted an efficient dose-dependent cytotoxic effect against normal Vero cell lines whose viable cell count decreased with increase in AgNPs concentration. Consistent with our study results, incubating human normal cell lines (WI 38) was affected by higher AgNPs concentrations (Salem et al, 2020;Algotiml et al, 2022). Based on the results of the in-vitro cytotoxicity and antibacterial activity, a safe dosage of 100mg/mL was selected for wound patches application to evaluate their antibacterial activity against S1 and E1 strains, the common dermatophyte pathogens found in wounds and burns.…”

Silver nanoparticles synthesized from the seaweed Sargassum polycystum and screening for their biological potential

“…Absorption peaks of AgNPs capped by U. rigida , C. myrica , and G. foliifera appearedat 424 nm, 409 nm, and 415 nm, respectively. These types of UV–VIS spectroscopy absorption peak obtained by Algotiml et al 19 . They reported that silver nanoparticles showed a peak value at 422 and 425 nm for Codiumcapitatum seaweeds of dried and fresh respectively.…”

Phytochemical and Potential Properties of Seaweeds and Their Recent Applications: A Review

“…Thymoquinone (TQ) is one of the most important bioactive elements of black seeds, and it has been found to have numerous health advantages, including cancer prevention and treatment. Following on this, Algotiml et al [250] studied the effect of biosynthesized Red Sea marine algal silver nanoparticles AgNPs on anticancer and antibacterial properties and the authors stated that due to their relatively moderate side effects, marine resources are currently being increasingly examined for antibacterial and anticancer medication prospects.…”