Antifungal activity of selected Malaysia’s local medicinal plants against sick building syndrome (SBS) fungi

Abstract

Background and Objective: Indoor air quality plays an important role in human health. One of the negative impacts of poor indoor air quality is sick building syndrome (SBS). The main factor that contributes to SBS is biological pollutants such as; fungi, bacteria and viruses. This study aimed to explore the antifungal potential of four medicinal plants in Malaysia namely Vitex trifolia, Vernonia amygdalina, Cassia alata and Strobilanthes crispus against 2 of the predominant SBS fungi (Aspergillus niger and Penicillium oxalicum). Materials and Methods: The plant samples were extracted by using the Soxhlet extraction technique. Antifungal screening was conducted by using disc diffusion sensitivity tests. Results: The results showed that S. crispus extract had the most effective antifungal activity against A. niger and P. oxalicum, with inhibition diameter of 11.1±0.0 mm (×2 (3) = 4.520, P = 0.034) and19.1±0.7 mm (×2 (3) = 8.520, P = 0.014), respectively. The S. crispus extract showed the minimum inhibitory concentration of 10 and 5 mg mL-1 for A. niger and P. oxalicum, respectively. Thin layer chromatography technique with solvent ratio 12:8:1 (hexane, chloroform, acetic acid) was applied to fractionate the active compounds from S. crispus extract and indicates the presence of flavonoids, alkaloids and terpenoids. However, the active compound efficacy test showed that single active compounds of S. crispus were unable to inhibit the fungi growth effectively. Conclusion: The S. crispus extract was the most effective antifungal agent against P. oxalicum and A. niger. However, the active compound separation did not exhibit any antifungal activity.