Vernonia colorata (Drake) leaf extract found to have strong resistance modulatory activity against certain bacteria

In this study, researchers at the Kwame Nkrumah University of Science and Technology in Ghana investigated the ability of vernolide from Vernonia colorata (bitterleaf) to modulate the resistance of pathogenic bacteria toward known antibiotics. Their findings were published in The Journal of Phytopharmacology.

• The resistance modulatory activities of natural products have gained scientific interest in recent years.
• In line with this, the researchers looked at the anti-microbial activity of vernolide from V. colorata and its ability to reverse the anti-microbial resistance of certain microbes toward conventional antibiotics.
• They first confirmed the identity of the compound using spectroscopy then evaluated its anti-microbial activity using MTT assay.
• The researchers reported that vernolide was effective against Escherichia coli, Staphylococcus aureus and Enterococcus faecalis with minimum inhibitory concentrations (MICs) of 0.3, 0.3 and 0.4 mg/mL, respectively.
• Meanwhile, the MICs of their selected antibiotics, namely, ciprofloxacin, amoxicillin, tetracycline and erythromycin, ranged between 0.1 to 16 mcg/mL.
• Modulation studies showed that the addition of 0.2 mg/mL vernolide to varying concentrations of the antibiotics (four to 0.0005 mcg/mL), which were well below their observed MICs, helped prevent microbial growth.

Based on these results, the researchers concluded that vernolide from V. colorata has strong resistance modulatory activities which can help reverse microbial drug resistance to modern antibiotics.

Read the full study at this link.

Journal Reference:

Adu JK, Twum K, Brobbey A, Amengor C, Duah Y. RESISTANCE MODULATION STUDIES OF VERNOLIDE FROM VERNONIA COLORATA (DRAKE) ON CIPROFLOXACIN, AMOXICILLIN, TETRACYCLINE AND ERYTHROMYCIN. The Journal of Phytopharmacology. 2018; 7(5): 425-430.