Isolation, identification, and antimycotic activity of plumbagin from Plumbago europaea L. roots, leaves and stems

Plumbago europaea L. is a plant utilized in Palestinian ethnomedicine for the treatment of various dermatological diseases. The current investigation was designed to isolate plumbagin from P. europaea leaves, roots and for the first time from the stems. Moreover, it aimed to evaluate the antimycotic activity against three human fungal pathogens causing dermatophytosis, also against an animal fungal pathogen. The qualitative analysis of plumbagin from the leaves, stems, and roots was conducted using HPLC and spectrophotometer techniques, while the structure of plumbagin was established utilizing Proton and Carbon-13 Nuclear Magnetic Resonance (NMR) and Infrared (IR) techniques. The entire plant constituents were determined by GC-MS. Moreover, the antimycotic activity against Ascosphaera apis, Microsporum canis, Trichophyton rubrum, and Trichophyton mentagrophytes was assessed utilizing the poison food technique method. The percentage of plumbagin recorded in the leaves, stems, and roots was found to be 0.51±0.001%, 0.16±0.001%, and 1.65±0.015%, respectively. The GC-MS examination declared the presence of 59 molecules in the plant extract. The plant extract and pure plumbagin exhibited complete inhibition against all tested dermatophytes at 6.0mg/mL for the extracts and 0.2mg/mL for plumbagin. P. europaea root is the best source of plumbagin and the plant extract could represent a potential drug candidate for the treatment of dermatophytosis infections. Further studies required to design suitable dosage forms from the natural P. europaea root extracts or plumbagin alone, to be utilized for the treatment of dermatological and veterinary ailments.