The evaluation of the effectiveness of selected antimicrobial plant extracts coating on textiles

Abstract

Antimicrobial textile development has increased due to microbial growth which is a global health threat facing humanity. Microbial growth can be inhibited by employing an antimicrobial agent or coating application to prevent and treat infections from humans to plants. This study aims to provide information on the effectiveness of the selected plant extracts from South African biomass (Eucalyptus globulus and Artemisia afra) coated on textiles for application as biomedical textiles. The extracts were prepared by pulsed ultrasound-assisted solvent extraction method. A simple immersion method was used to coat the polyester and cotton fabrics. The extracts have also been analysed for their yields, antimicrobial activity, phytochemical analysis (phytochemical screening) minimum inhibitory concentration, zone of inhibition and washing durability. The methanolic extractions show the highest yields compared to the hexanoic Artemisia afra and Eucalyptus globulus extractions. Phytochemical screening of Artemisia afra and Eucalyptus globulus crude leaf extract was determined. The results showed that all extracts contain the bioactive compounds phenolic compounds, quinones, and sterols. The Eucalyptus globulus hexanoic extracts showed the highest antibacterial activity which has high inhibition zones against Gram-positive bacteria S. aureus ATCC 33591 followed by the methanolic Eucalyptus globulus extract. Artemisia afra methanol extracts showed higher antibacterial activity than that of the hexanoic extract against S. aureus ATCC 33591. The methanol extracts had higher inhibition zones against Gram-positive and Gram-negative bacteria. Among the crude extracts, the highest zone of inhibition (258.4 mm2) was recorded against S. aureus ATCC 33591 when the E. globulus methanolic extract was applied to the cotton fabric. On the other hand, the lowest inhibition was exhibited on the E. globulus methanolic extract coated on polyester fabric (65.97 mm2). Bioactivity was only detected against the S. aureus strain. MIC values of the different extracts showed varied results. The MIC for the samples tested is therefore all >500 !g/ml. The MIC values obtained from antimicrobial tests ranged from 5-500 μg/ml (Table 5). The results showed that the bacterial strain S. aureus ATCC33591 was the most sensitive to A. afra methanol extract with a MIC value of 5 μg/ml to 25 μg/ml. Furthermore, the inhibition zone was determined after laundering and no activity was found in the samples. This might be due to the preparation of fabric, inactivation of active compounds during the treatment/preparation of the material samples, or improper binding of the active compounds to the textile material.