Nature’s Nanofactory: Leveraging Medicinal Plants as Novel Therapeutics

With the emergence of antibiotic resistance, there is an increase in illness, death, and healthcare costs and it also poses a threat to medical procedures. Novel therapeutic agents with a multi-pronged effect are therefore urgently required so as to impede bacterial mutations that lead to antibiotic resistance strategies. Metallic nanoparticles, particularly those containing silver, have been showing promise to fulfil this role and these nanoscale powerhouses could be our answer. Green biochemical synthetic strategies coupled with traditional medicine have therefore gained popularity as it results in an eco-friendly strategy for nanoparticle synthesis and the added benefit of medicinal phytochemicals being incorporated into the nanoparticle thereby resulting in a potent antibacterial agent. This study therefore made use of the medicinal plant, Siphonochilus aethiopicus, which is known to contain antibiotic compounds for the synthesis of silver nanoparticles. These nanoparticles were found to have excellent broad-spectrum antibiotic activity when tested using the INT assay. When the silver nanoparticles were tested against Acinetobacter baumannii (ATCC 19606), concentrations of 50 µg/ml and higher resulted in more than 90% toxicity. Against Pseudomonas aeruginosa (ATCC 27853), more than 80% toxicity was achieved with 25 µg/ml of the silver nanoparticles and more than 90% toxicity resulted when concentrations of 50 µg/ml or higher were evaluated. These results were comparable to the positive control ciprofloxacin. The silver nanoparticles also displayed more than 90% toxicity against Enterococcus faecalis (ATCC 51299) at concentrations of 25 µg/ml and higher, comparable to the positive control ampicillin. Against Staphylococcus aureus (ATCC 43300), more than 90% toxicity was achieved at concentrations of 25 µg/ml and higher, and of note these results indicated that the silver nanoparticles performed slightly better than the positive control ciprofloxacin. These nanoparticles therefore show excellent potential to be further developed as novel antibiotics.