In-vitro anti-gonorrheal activity of a sesquiterpene lactone, xerantholide isolated from the leaves of Pechuel-loeschea leubnitziae

Gonorrhea is the second most prevalent bacterial sexually transmitted infection in the world. The global increase in the spread of gonorrhea is due to the fact that Neisseria gonorrhoeae has developed resistance to antimicrobials used as first-line treatments. In the search for new anti-gonorrheal agents, this study seeks to validate the use of a medicinal plant, namely, Pechuel-loeschea leubnitziae, for which both the root and the leaf extracts are commonly used as a remedy for gonorrhea. Bioassay guided fractionation of dichloromethane and methanol crude extracts (MIC50 = 0.730 - 3.07 mg/mL) was carried out. From the most active fraction F6, nearly colorless crystals were isolated and single crystal X-ray diffraction analysis identified the compound as a known sesquiterpene lactone, xerantholide. The compound showed activity against N. gonorrhoeae (MIC50 = 0.095 mg/mL) comparable with tetracycline, a positive control. This study shows that P. leubnitziae extracts have in-vitro anti-gonococcal activity and that xerantholide is the active anti-gonorrheal ingredient. The finding supports the traditional use of this plant to treat gonorrhea. This is the first report on the activity of xerantholide isolated from P. leubnitziae crude leaf extract against N. gonorrhoeae. (C) 2022 SAAB. Published by Elsevier B.V. All rights reserved.

Automated summary

Gonorrhea is a common sexually transmitted infection caused by Neisseria gonorrhoeae, which has developed resistance to first-line antimicrobial treatments. This study validates the use of Pechuel-loeschea leubnitziae, a medicinal plant, for the treatment of gonorrhea and identifies xerantholide as the active ingredient with anti-gonorrheal activity.