Browsing by Author "Abrantes, Pedro"

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    Aloe ferox, Agathosma betulina, and Bulbine frutescens extracts show antifungal activity at concentrations favourable to the proliferation of epidermal cells
    (Elsevier GmbH, 2025) Ndlovu, Banele; Klaasen, Jeremy; Abrantes, Pedro; Africa, Charlene; Fisher (née Rahiman), Farzana
    Introduction: The increasing prevalence of antifungal resistance presents an enormous challenge to healthcare professionals. The adverse effects and resistance of current antifungal drugs have prompted the need for alternate antifungal therapy in the form of natural products. Although anecdotal reports have suggested that Aloe ferox, Agathosma betulina, and Bulbine frutescens have been used to successfully treat fungal skin infections, little scientific evidence is available to validate these claims. Therefore, this study aimed to determine whether the concentrations of A ferox, A betulina, and B frutescens hydroethanolic extracts showing antifungal activity against skin-related Candida species are cytotoxic to normal human epidermal cells. Methods: Crystal violet and lactate dehydrogenase assays were employed to determine cell viability and cytotoxicity on the human epidermal cells. Broth microdilutions were performed to evaluate the susceptibility of Candida species to plant extracts. Results: Candida spp. inhibition was observed at a concentration of 200 µg/ml, while optimum extract concentrations for cell proliferation ranged between 200 and 400 µg/ml for B frutescens and 200 µg/ml for A ferox and A betulina. This suggests that these plants could prove to be effective as antifungal agents at a dosage of 200 µg/ml while still supporting the growth of epidermal cells at the same concentration, which is an important process in maintaining healthy skin. Conclusions: These findings from this study lay a foundation for further studies confirming the applicability of these medicinal plants as safe alternative antifungal treatments that promote skin cell proliferation, regeneration, and enhance tissue repair.
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    Insights into the prevalence and resistance patterns of candida species among diabetic patients in Cameroon: Potential paths for alternative treatments
    (Science and Education Publishing, 2024) Abrantes, Pedro; Tsague, Kenfack; Dongmo, Dongho; Kouipou, Toghueo
    The study aimed to fill the knowledge gap regarding the prevalence of Candida infections in diabetic patients and their sensitivity to antifungal drugs. Clinical samples from diabetic patients were collected at Yaoundé Central Hospital and Candida species identified. The ability of these species to form biofilms was assessed, and their susceptibility to usual antifungal drugs, as well as some plant extracts and fractions, was determined. Mycological diagnosis was performed on the collected samples. The Candida species isolated and identified were subjected to the crystal violet assay in a microtiter plate to examine their biofilm-forming abilities. The disk diffusion method was used for susceptibility testing for reference antifungals, while the broth dilution method was employed for plant extracts and fractions. These were obtained from the leaves of Picralima nitida, Phragmanthera capitata, and Spondia cythereae, and the roots and fruits of Garcinia Kola. The study found that 43.18% of the 396 collected samples were colonized by various Candida species, including Candida albicans, Candida tropicalis, Candida parapsilosis, Candida glabrata, Candida krusei, Candida guillermondii, Candida lusitaniae, and Candida ciferrii. Biofilm production was observed in 46.04% of the isolates, with non-albicans Candida species showing a higher rate than Candida albicans. The isolates exhibited high resistance to nystatin and ketoconazole, dose-dependent sensitivity to miconazole, and sensitivity to econazole and fluconazole. Multidrug resistance was observed in 24.75% of the isolates. While none of the crude extracts showed activity against the tested Candida, six out of 25 fractions (PnlB, PclA, PclW, SclA, SclW, and GkfW) displayed fungistatic activities on some strains. These findings offer valuable insights into the prevalence and antifungal resistance patterns of Candida species in diabetic patients in Cameroon. They also suggest the potential for alternative treatments using plant fractions.
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    Monitoring of candida biofilm inhibition by galenia africana using real-time impedance-based technology
    (Current Medical Mycology, 2024) Abrantes, Pedro; Stuurman, Keith Chesnay; Klaasen, Jeremy Arthur; Africa, Charlene Wilma Joyce
    Background and Purpose: Yeasts of the Candida genus are responsible for localized and disseminated infections, especially in immunocompromised populations. These infections are exacerbated by the rapid increase in drug-resistant strains, which limits treatment options and increases patient morbidity and mortality. Therefore, the utilization of easily accessible natural products as alternatives to conventional medicines has gained interest. South Africa is home to a rich biodiverse natural flora of which many are known for their antimicrobial activity, including the antifungal effects of their plant extracts. Galenia africana (kraalbos) is a local indigenous plant found to have various traditional uses, including the treatment and prevention of various human infections. Materials and Methods: In this study, the activity of G. africana against Candida albicans and Candida glabrata preformed biofilm formation and its antibiofilm activity were tested using the xCELLigence system, which monitors biofilm formation in real time using impedance. Results: Presence of G. africana resulted in a dose-dependent decrease in Candida biofilms and was found to be effective in the prevention of Candida biofilm formation and disruption of the existing Candida biofilms. Conclusion: The xCELLigence impedance-based system proved to be an effective tool for medication screening. To the best of our knowledge, this is the first reported study to use real-time monitoring of a medicinal plant on microbial biofilm formation.