Antifungal, Antibacterial, and Cytotoxic Activities of Silver Nanoparticles Synthesized from Aqueous Extracts of Mace-Arils of Myristica fragrans.

In the present study, mace-mediated silver nanoparticles (mace-AgNPs) were synthesized, characterized, and evaluated against an array of pathogenic microorganisms. Mace, the arils of Myristica fragrans, are a rich source of several bioactive compounds, including polyphenols and aromatic compounds. During nano synthesis, the bioactive compounds in mace aqueous extracts serve as excellent bio reductants, stabilizers, and capping agents. The UV-VIS spectroscopy of the synthesized NPs showed an intense and broad SPR absorption peak at 456 nm. Dynamic light scattering (DLS) analysis showed the size with a Z average of 50 nm, while transmission electron microscopy (TEM) studies depicted the round shape and small size of the NPs, which ranged between 5-28 nm. The peaks related to important functional groups, such as phenols, alcohols, carbonyl groups, amides, alkanes and alkenes, were obtained on a Fourier-transform infrared spectroscopy (FTIR) spectrum. The peak at 3 keV on the energy dispersive X-ray spectrum (EDX) validated the presence of silver (Ag). Mace-silver nanoparticles exhibited potent antifungal and antibacterial activity against several pathogenic microorganisms. Additionally, the synthesized mace-AgNPs displayed an excellent cytotoxic effect against the human cervical cancer cell line. The mace-AgNPs demonstrated robust antibacterial, antifungal, and cytotoxic activity, indicating that the mace-AgNPs might be used in the agrochemical industry, pharmaceutical industry, and biomedical applications. However, future studies to understand its mode of action are needed.

Postharvest disease management of Alternaria spots on tomato fruit by Annona muricata fruit extracts.

The aim of this study was to assess Annona muricata L. fruit extracts as an alternative to synthetic fungicide against Alternaria alternata (Fries) Keissler, the causative agent of black spots of tomato fruit. Antifungal activities of A. muricata pulp and seed extracts were tested both in vitro and in vivo. The seed extracts were more potent at inhibiting A. alternata than the pulp extracts. The in vitro assay showed maximum inhibition of radial mycelial growth of A. alternata (90%) by methanol seed extracts, at the highest concentration of 6%. Similarly, the in vivo assay showed marked reduction in lesion diameter (2.1 mm) and consequent disease inhibition (84%) on the tomato fruit treated with methanol seed extracts. Scanning electron microscopy showed that A. muricata extracts significantly damaged the morphology of hyphae and conidial structures. The FT-IR spectrum obtained from methanol extracts showed bands representing important bioactive compounds that possess antifungal activity. Based on our findings, Annona muricata fruit extracts can be further explored as a potential, excellent alternative approach to control the postharvest Alternaria spots of tomato fruit.

Comparative analysis of chemical, mineral and in-vitro antibacterial activity of different varieties of date fruits from Saudi Arabia.

Three important varieties of dates (Sukri, Barhi, and Rothana), grown in Saudi Arabia were analyzed for their chemical, mineral and anti-bacterial activity. Among all the varieties analyzed, the Sukri dates had the highest moisture (16%), carbohydrate (80.65 mg/g) and the phenolic content (1.24 mg GAE/100 g) whereas, the ash content was the lowest (2.22%). The mineral content analyzed by ICP OES reveals that all three varieties contain an appreciable amount of essential macro and micro nutrients. They contain a good amount of potassium; the maximum amount of K (8171.24 mg/kg) was recorded in Barhi dates. Besides that, all three varieties of dates contain a good amount of Se, Cu, P, Fe, Mn. The comparative analysis of the GC MS chromatogram reveals that there were only five compounds that were present in all three varieties. The bioactive compounds Mannoic and Lactone were detected in all three varieties. The fruits contain some important groups of sugar, alcoholic sugar, aromatic hydrocarbon, phenol(s) and esters. The extracts of dates were assed for their antibacterial activity against 6 important strains of human pathogenic bacteria. The strains of E. coli-ATCC25922, B. subtilis-ATCC6633, S. aureus-ATCC25923, were observed to be highly sensitive to most of the extracts whereas S. pyogenes and S. flexeneri (clinical isolates) showed moderate sensitivity to some extracts. The variety Sukri was found to be superior to the other two varieties in terms of sugar and phenolic contents, in addition, the methanol extract of Sukri dates showed excellent antibacterial activity against most of the bacteria evaluated. These varieties of dates prove to have immense potential to be utilized as a therapeutic agent for curing mineral deficiency also can be explored for developing antibacterial agents.