Antibacterial and synergistic effects of Smallanthus sonchifolius leaf extracts against methicillin-resistant Staphylococcus aureus under light intensity

Abstract

Smallanthus sonchifolius (yacon) is a perennial plant mostly cultivated in South America, primarily for use of the tubers as a food crop and the leaves as fodder for livestock. The antibacterial activities of the methanol extract of yacon leaves (S. sonchifolius) and its n-hexane, ethyl acetate, n-butanol and water fractions were evaluated against 6 strains of methicillin-resistant Staphylococcus aureus (MRSA) and 1 standard methicillin-susceptible S. aureus (MSSA) strain by using the disc diffusion method and minimal inhibitory concentrations (MICs) assay in the presence and absence of light. No activity was detected when the two methods were performed without light; however, under illumination at 4000 lux, the n-hexane fraction of yacon (HFY) had a MIC of 15.6 microg/ml. HFYL, prepared by exposure of HFY to 4000 lux for 18 h, was more effective than HFY in terms of antimicrobial activity against the 6 MRSA strains and 1 standard MSSA strain. HFYL mixed with ampicillin or oxacillin showed a synergistic effect with all fractional inhibitory concentrations values being below 0.5. The present study demonstrates the enhancement and antimicrobial activity of yacon leaves against MRSA in the presence of light.

Evaluation of wound healing and antimicrobial properties of aqueous extract from Bowdichia virgilioides stem barks in mice

“…Moreover, findings from the present study showed that AEBv was effective against a methicillin-resistant strain of S. aureus (MRSA). These MRSA are difficult to treat because they are also multiresistant and up to now there are no satisfactory antimicrobial drugs (Joung et al 2010). Therefore, regarding to the present result, extract from B. virgilioides seem to be a potential tool to combat the problem of MRSA.…”

“…As Standards (2003). A modified diffusion test was used to determine the antimicrobial activity (Joung et al 2010). The colonies were taken directly from the plate and were suspended in 5 mL of sterile 0.85% saline.…”

Influence of the Addition of Ovalbumin and Emulsifier on the Physical Properties and Stability of Yacon (Smallanthus sonchifolius) Juice Foams Prepared for Foam Mat Drying Process

“…Studies have reported that yacon also presents antioxidant activity related to compounds such as flavonoids (Arnao et al 2011), phenolic acids (Castro et al 2012), and tryptophan (Yan et al 1999), beyond anti-inflammatory (Honoré et al 2012), anti-obesity (Hasani-Ranjbar et al 2013), antibacterial (Joung et al 2010), antifungal (Yun et al 2012), and anticancer (Moura et al 2012) activities.…”

Smallanthus sonchifolius

“…Under light illumination at 4,000 lux for 18 hours, the n-hexane fraction of yacon leaf methanol extract showed antibacterial effect against six strains of methicillin-resistant Staphylococcus aure us (MRSA) and one standard methicillin-susceptible S. aureus (MSSA) with a MIC of 15.6 μg/mL (Joung et al 2010 ). No activity was detected in the absence of light.…”

“…Smallanthus sonchifolius (yacon) is a perennial plant mostly cultivated in South America, primarily for use of the tubers as a food crop and the leaves as fodder for livestock (Joung et al 2010 ).…”