Phytochemical composition and antibacterial activity of Sonchus oleraceus (L.) L. on Enterococcus faecalis

Abstract

The unprecedented rapid emergence of resistant bacteria occurring worldwide is imperiling the worth of antibiotics which have transformed medical sciences. Antibiotic- resistant infections are already spread in the US and across the world. A 2011 national survey (in US) of infectious- disease specialists by IDSA Emerging Infections Network, found that more than 60% of the participants have seen a pan- resistance, untreatable bacterial infection within the prior year. The CDC declared in 2013 that the human race is now in the “post- antibiotic era” and in 2014, the World Health Organization (WHO) warned that the antibiotic resistance is becoming dire. According to the CDC, more than two million people in the US become ill with antibiotic resistant diseases every year, resulting in a minimum of 23,000 deaths. This study aimed at determining the antibacterial activity of Sonchus oleraceus (L.) L. against Enterococcus faecalis. Phytochemical analysis of the leaves of Sonchus oleraceus L. showed presence of tannins, phenols, alkaloids, saponins and flavonoids. The ethanolic leaf extract showed a high antibacterial activity. The antibacterial susceptibility patterns of the ethanolic extract determined using the Kirby – Bauer method showed an inhibition zone diameter of 12 mm which was lower than levoflaxacin’s inhibition zone diameter of 42 mm. Minimum inhibitory concentration (MIC) determined using the Broth microdilution assay showed MIC of 125 µg/ml and lastly, minimum bactericidal concentration (MBC) was 125 µg/ml (this was determined by sub culturing). In conclusion, this study showed that the ethanolic leaf extract of Sonchus oleraceus L. had an antibacterial activity against Enterococcus faecalis. I recommend that other plant parts should also be investigated for their antibacterial potential, toxicology studies on Sonchus oleraceus L. ethanolic leaf extract should be carried out so as to produce an efficient pharmacological product and further research should be done using different solvents like methanol, diethyl ether, water to find out if there are any differences connected to the choice of solvent.