Antibacterial and antioxidant activity of different extracts obtained from Withania somnifera (Ashwagandha)

Ashwagandha (W. somnifera) is widely known as the queen of Indian Ayurveda. The objective of this study was to determine the antioxidant and antibacterial activity of the different parts of the Ashwagandha. The antioxidant activity of different extracts from different parts of Ashwagandha was determined using DPPH free radical scavenging method. Ashwaghanda root inhabiting bacteria was isolated using pour-plate technique. The agar well method and filter paper method were followed to assess the antibacterial activity of the extracts. Ethanol-water extracts (1:1 v/v) gave higher yield of extractable matter than methanol extracts. The antioxidant activity of fresh root extract was significantly higher than other parts of the plant (stem and leaves) as well as the plant material bought from open market. The minimal inhibitory concentration (MIC) values of Ethanol-water extract against MRSA, Candida Sp. and Salmonella Sp. were >256 mg/L. The commensal bacteria (Bacilli Sp.) inhabiting Ashwagandha roots displayed mild antibacterial activity against pathogenic P. aeruginosa. Keywords: Ashwaghanda, commensal bacteria, Antibacterial activity, Antioxidant activity, Crude extracts

Encapsulation of Natural Bioactive Compounds by Electrospinning—Applications in Food Storage and Safety

Packaging is used to protect foods from environmental influences and microbial contamination to maintain the quality and safety of commercial food products, to avoid their spoilage and to extend their shelf life. In this respect, bioactive packaging is developing to additionally provides antibacterial and antioxidant activity with the same goals i.e., extending the shelf life while ensuring safety of the food products. New solutions are designed using natural antimicrobial and antioxidant agents such as essential oils, some polysaccharides, natural inorganic nanoparticles (nanoclays, oxides, metals as silver) incorporated/encapsulated into appropriate carriers in order to be used in food packaging. Electrospinning/electrospraying are receiving attention as encapsulation methods due to their cost-effectiveness, versatility and scalability. The electrospun nanofibers and electro–sprayed nanoparticles can preserve the functionality and protect the encapsulated bioactive compounds (BC). In this review are summarized recent results regarding applications of nanostructured suitable materials containing essential oils for food safety.

Bioprospection of Enggano Macroscopic Fungi as Antibacterial and Antioxidant Agents

Macrofungi in Indonesia have not been widely studied for their pharmacological activity, especially as a source of antibacterial and antioxidant properties, even though Indonesia as a tropical country has quite a high diversity of macrofungi. This study aims to reveal the potential of macrofungi from the Enggano forest as a source of antibacterial and antioxidant compounds. Four types of macrofungi were collected and their metabolites were extracted using four types of organic solvents. Antibacterial and antioxidant activity assay of the extract was carried out using the TLC Bioautography method. From the sixteen macrofungal extracts, there is one extract that has the strongest antibacterial activity compared to the others, namely n-hexane Coriolopsis polyzona. It showed moderate antibacterial activity against Staphylococcus aureus and Escherichia coli with MIC values of 256–128 μg/mL, respectively. Meanwhile, the antioxidant activity of the macrofungal extracts showed weak activity with IC50 values of 3080–7370 μg/mL (AAI values of 0.033–0.079).

In Situ Grafting of Silica Nanoparticle Precursors with Covalently Attached Bioactive Agents to Form PVA-Based Materials for Sustainable Active Packaging

Sustainable antibacterial–antioxidant films were prepared using in situ graftings of silica nanoparticle (SNP) precursors with covalently attached bioactive agents benzoic acid (ba) or curcumin (cur) on polyvinyl alcohol (PVA). The modified PVA-SNP, PVA-SNP-ba and PVA-SNP-cur films were characterized using spectroscopic, physicochemical and microscopic methods. The prepared films showed excellent antibacterial and antioxidant activity, and increased hydrophobicity providing protection from undesired moisture. The PVA-SNP-ba films completely prevented the growth of the foodborne human pathogen Listeria innocua, whereas PVA-SNP-cur resulted in a 2.5 log reduction of this bacteria. The PVA-SNP-cur and PVA-SNP-ba films showed high antioxidant activity of 15.9 and 14.7 Mm/g TEAC, respectively. The described approach can serve as a generic platform for the formation of PVA-based packaging materials with tailor-made activity tuned by active substituents on silica precursors. Application of such biodegradable films bearing safe bioactive agents can be particularly valuable for advanced sustainable packaging materials in food and medicine.