resumo
Acanthamoeba keratitis infection extends due to the growing number of contact lens users. Indigenous plants including Garcinia mangostana play a vital role in human health and well being. Many species of this plant have been reported with myriads of potent medicinal properties. However, the aims of this study were, for the first time, to isolate compounds from the flower of G. mangostana and to test their anti-Acanthamoeba and anti adhesion activity against Acanthamoeba triangularis. Powdered flowers of G. mangostana were extracted and chromatographed on a silica gel column. The structures of the compounds were established with the aid of 1H NMR. More so, the anti-Acanthamoeba and anti-adhesion properties were tested on a 96-well polystyrene microtiter plate and soft contact lenses. Scanning electron microscope (SEM) was used to determine the features of A. triangularis on contact lenses. Eight pure compounds were obtained, namely 9-hydroxycalabaxanthone, tovophillin A, garcinone E, garcinone B, alpha-mangostin, gartinin, 8-deoxygartinin and gamma-mangostin. The extract and pure compounds exhibited anti-Acanthamoeba activity with MIC values in the range of 0.25-1 mg/mL. In addition, the extract and alpha-mangostin displayed significant activity against the adhesion of A. triangularis trophozoites both in polystyrene plate and in contact lenses at 0.5 x MIC (0.25 mg/mL). Furthermore, alpha-mangostin has the potential to remove A. triangularis adhesion in contact lenses similar to a commercial multipurpose solution (MPS). SEM study confirmed that crude extract and alpha-mangostin are effective as solutions for contact lenses, which removed A. triangularis trophozoites within 24 h. Alpha-mangostin was non-toxic to Vero cells at a concentration below 39 mu M in 24 h. Crude extract of G. mangostana flower and its alpha-mangostin serve as candidate compounds in the treatment of Acanthamoeba infection or as lens care solution, since they can be used as a source of natural products against Acanthamoeba and virulence factor associated with the adhesion of A. triangularis.
palavras-chave
XANTHONES; KERATITIS; ADHESION; DISEASE; AMEBAS; SPP.; L.
categoria
Parasitology; Tropical Medicine
autores
Sangkanu, S; Mitsuwan, W; Mahboob, T; Mahabusarakam, W; Chewchanwuttiwong, S; Siphakdi, P; Jimoh, TO; Wilairatana, P; Dolma, KG; Pereira, MD; Rahmatullah, M; Wiart, C; Norouzi, R; Siyadatpanah, A; Mutombo, PN; Nissapatorn, V
nossos autores
agradecimentos
We highly appreciate for the support of Thailand and the Research Institute of Health Science (RIHS) at Walailak University for the labo-ratory facilities. We would also like to acknowledge the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 and UIDP/50011/2020, national funds by FCT/MCTES.