The antifungal activity and safety of Maesa lanceolata against common opportunistic fungal pathogens

The antifungal activity and safety of Maesa lanceolata against common opportunistic fungal pathogens. Timothy K. Chemweno 1,* , Lizzy Mwamburi 1 , Lucia Keter 2 , Brian Kipng’etich 1 , Chrispus Ngule 2 , Christine Bii 3 1 Department of Biological Sciences, University of Eldoret, Eldoret, Kenya 2 Center for Traditional Medicine and Drug Research, Kenya Medical Research Institute, Nairobi, Kenya 3 Center for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya _____________ * Corresponding author: Department of Biological Sciences, University of Eldoret, Eldoret, Kenya, P.O. Box 1125-30100 Eldoret, Cell 0720822615; Email: timothyjohn3@gmail.com ABSTRACT Aim: The aim of this research was to investigate the in vitro antifungal activity and safety of aqueous, dichloromethane and methanolic extracts of Maesa lanceolata against common opportunistic fungal pathogens. Study design: This was a laboratory based experiment with the extraction of crude extracts from air-dried leaves, roots and stem bark samples of M. lanceolata: phytochemical screening, determination of antifungal potential and safety of the extracts. Place and duration of study: The stem bark, roots and leaves of M. lanceolata were collected and extracted separately with distilled water, methanol and dichloromethane then tested for the presence of phytochemicals at CTMDR laboratory, KEMRI. The antifungal activity of the extracts was done at Mycology Laboratory, Center for Microbiology, KEMRI. The extracts were tested against some American Type Culture Collections (ATCC) and clinical isolates; Candida glabrata ATCC 24433, Cryptococcus neoformans, Microsporum gypseum , Trychophyton mentagrophtes and Aspergillus flavus using agar-disc diffusion and broth dilution methods. Results: Out of the five fungi tested, four were inhibited by the methanolic, dichloromethane and water extracts to varying degrees except A. flavus that proved to be resistant to the extracts assayed. Water extracts of M. lanceolata root and stem bark were highly active against C. glabrata ATCC 24433 strain with zone inhibition diameter and minimum inhibitory concentration (MIC) values of 23.33mm, MIC 31.25 mg/ml and 19.67mm, MIC value 125mg/ml respectively.  C. neoformans was least resistant to methanol and aqueous root extracts of M. lanceolata both displaying zone diameter of inhibition and MIC values of 18mm and 15.63mg/ml respectively. Phytochemicals present include alkaloids, phenols, terpenoids, anthraquinones and tannins. The selected M. lanceolata leaves (dichloromethane and methanol) extracts and stem bark (dichloromethane and aqueous) extracts displayed varying degrees of cytotoxicity on Vero E6 cell lines with cytotoxicity concentration (CC 50 )  ranging from 206 µg/ml to 684 µg/ml. Conclusion The activity of stem bark, root and leave extracts of M. lanceolata confirms its use in traditional medicine. Key words: Antifungal activity, Maesa lanceolata, fungal pathogens, extracts