Phytochemical and Antibiofilm Activity of Aloe barbadensismiller (Aloe vera) on Candida albicans Isolated from Urinary Catheter

Aims: To screen for phytochemicals present in Aloe barbadensismiller (Aloe vera) growing within the Main Campus of Nasarawa State University Keffi (NSUK), determine biofilm forming ability, and to investigate the antibiofilm activity of the plant extracts on biofilm formed by clinical isolates of Candida isolated from urinary catheters.

Study Design: The leaf of Aloe vera were collected and maceration method was used to extract the plant materials used for the screening of bioactive components. Swab samples were collected from the surfaces of patients’ urinary catheters presenting at Federal Medical Centre and Nagari Hospital, Keffi respectively, irrespective of their ages and sexes. Biofilm forming ability of the isolates was investigated and the antibiofilm activity of the plant extracts determined. Ordinary one-way ANOVA was used to analyze the data where P = .05.

Place and Duration of Study: The research was carried out in the Microbiology Laboratory of NSUK, using the Aloe vera plant collected within the University community and the biofilm analysis was conducted at National Veterinary Research Institute, Vom Plateau State, between October 2018 to March 2019.

Methodology: Both the aqueous and ethanolic extracts were screened for aloin, tannins, saponins, glycosides, flavonoids, phenols, alkaloids etc, and the Candida species were subjected to biofilm formation in a flat bottom 96-well microtiter polystyrene plate using crystal violet assay. Broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) of the extracts whereas, antibiofilm activity of the extracts was investigated by growing biofilms in the presence of Aloe vera leaf extracts.

Results: The presence of tannin, saponins, phenols, reducing sugars and aloin were found in the leaf aqueous extract while alkaloid, flavonoid, glycoside, tannin, phenols, reducing sugars, terpenoids, quinones and aloin in the ethanolic extract. Clinical isolates of Candida were found to be strong biofilm formers (70%). Both the aqueous and ethanolic extracts had significant effects on initial cell attachment where P = .05, however, none was able to achieve complete biofilm eradication, including the positive control ketoconazole. Ethanolic extract inhibits C. albicans cell attachment by 54.25%, aqueous extract 25.68% and ketoconazole has 48.54% percentage inhibition, respectively. Interestingly, ethanolic extracts showed a better antibiofilm property (37.38%) compared to ketoconazole that had 33.98% biofilm inhibition.

Conclusion: The leaf extracts of Aloe barbadensismiller has significantly reduced biofilm formed by clinical isolates of Candida. Coating of urinary catheters with A. vera extracts can decrease nosocomial infections, morbidity, and high mortality as well as financial burden, hence, serving as an alternative treatment for urinary tract infections.