Molecular characterization of methanol extract of Artemisia annua leaf and its antifungal activity on clinical isolates of Candida albicans

Abstract

Purpose: To molecularly characterize and determine the antifungal properties of methanol-leaf extract of Artemisia annua (A. annua) on   C. albicans isolates collected from three tertiary hospitals within Enugu State, Nigeria. Methods: Five hundred (500) isolates of Candida albicans were collected from medical microbiology laboratories in Bishop Shanahan  Hospital (BSH), University of Nigerian Teaching Hospital (UNTH), and Enugu State University Teaching Hospital (ESUTH). Anti-fungal  sensitivity profiles of different azoles were determined using the disk diffusion technique. Thirty of the collected isolates were evaluated  using the polymerase chain reaction (PCR) which targeted both 18S messenger RNA (rRNA) and Ergosterol II (ERGII) resistance gene sets  for C. albicans. Anti-fungal activity of different concentrations (25, 50, 100, 200, 400, and 800 µg/mL) of the extract of Artemisia annua on  resistant isolates was investigated using the agar well diffusion technique. Results: All the isolates were resistant to azole drugs  (ketoconazole (30 µg), miconazole (30 µg), clotrimazole (10 µg), itraconazole (30 µg), voriconazole (1 µg), and fluconazole (25 µg)). The  PCR revealed that thirteen isolates (43 %) were positive for 18S rRNA gene and nine (30 %) possessed ERGII-resistant gene. Primers  specific for C. albicans genotypes generated a PCR product of approximately 665 bp. Primers specific for ERGII resistant gene generated  PCR product of approximately 1.4 kb. Extract of A. annua had antifungal activity against resistant C. albicans isolates with minimum  inhibitory concentration ranging from 76.03 to 40.74 µg/mL. Conclusion: Resistant C. albicans species have been genotypically  characterized and the antifungal activity of A. annua has been reported. Methanol extract of A. annua inhibits C. albicans better than azole drugs.