Antidandruff property of <i>Psidium guajava</i> leaf extracts

<i>Psidium guajava</i> leaf paste and decoction have long been used in Mauritius for their efficacy in dandruff management. The study aimed to test <i>P. guajava</i> leaf extracts against fungi collected from dandruff patients' scalps, as previous research has shown a strong link between dandruff and dermatophytes. Fungi were isolated and cultured on Sabouraud dextrose agar (SDA), which contained 2% olive oil, 1% Tween 80, and chloramphenicol. The isolates were identified using physiological, macroscopic, microscopic, biochemical, and molecular techniques. Hydrodistillation and Soxhlet extraction of Mauritian <i>P. guajava</i> leaves were used to obtain essential oil and different solvent fractions, which were then screened for the presence of phytochemicals. The microdilution assay was used to test the antifungal activity of harvested extracts against isolates. <i>Neurospora intermedia</i>, <i>Trichoderma atroviride</i>, and <i>Trichosporon asahii</i> were identified as fungi. The solvents chloroform, methanol, and hexane produced higher extract yields (16.2%, 15.2% and 14.7%). The phytochemicals were most abundant in the chloroform-methanol (4:1 v/v) fraction. The methanol fraction had the highest total phenolic content (TPC), total flavonoid content (TFC), and total tannin content (TTC), with concentrations of 298.27 19.66 g GAE/g, 132.1 6.15 g QUE/g, and 118.53 1.60 g GAE/g, respectively. Isolates were most sensitive to chloroform-methanol (4:1 v/v) and methanol fractions, with a MIC of 1.56 mg/mL. From the study, it can be deduced that <i>P. guajava</i> leaf extracts are effective antifungal agents and potential ingredients for natural antidandruff hair products, which are in high demand in the cosmetic industry.