School of Allied Health Sciences, Southeast Asia Water Team (SEA Water Team), World Union for Herbal Drug Discovery (WUHeDD), and Research Excellence Center for Innovation and Health Products (RECIHP), Walailak University, Nakhon Si Thammarat, Thailand.
Akkhraratchumari Veterinary College, Walailak University, Nakhon Si Thammarat, Thailand.
Acta Trop. 2022 Feb;226:106266. doi: 10.1016/j.actatropica.2021.106266. Epub 2021 Dec 8.
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 H 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, α-mangostin, gartinin, 8-deoxygartinin and γ-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 α-mangostin displayed significant activity against the adhesion of A. triangularis trophozoites both in polystyrene plate and in contact lenses at 0.5 × MIC (0.25 mg/mL). Furthermore, α-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 α-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 μM in 24 h. Crude extract of G. mangostana flower and its α-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.
棘阿米巴角膜炎感染的病例因隐形眼镜使用者的数量不断增加而有所增加。藤黄属植物包括山竹果，在人类健康和福祉方面发挥着至关重要的作用。该植物的许多种都被报道具有无数的有效药用特性。然而，本研究的目的是首次从山竹花中分离化合物，并测试其对棘阿米巴原虫的抗阿米巴和抗黏附活性。山竹花粉末经提取后，在硅胶柱上进行色谱分离。借助核磁共振氢谱确定了化合物的结构。此外，还在聚苯乙烯微量滴定板和软性隐形眼镜上测试了抗棘阿米巴和抗黏附特性。扫描电子显微镜（SEM）用于确定隐形眼镜上棘阿米巴原虫的特征。从山竹花中获得了 8 种纯化合物，分别为 9-羟基卡瓦酮、托维醇 A、藤黄内酯 E、藤黄内酯 B、α-倒捻子素、garcinin、8-去氧倒捻子素和γ-倒捻子素。提取物和纯化合物均表现出抗棘阿米巴活性，MIC 值在 0.25-1mg/mL 范围内。此外，提取物和α-倒捻子素在聚苯乙烯平板和隐形眼镜中均表现出对棘阿米巴原虫营养体黏附的显著活性，在 0.5×MIC（0.25mg/mL）时，均表现出对棘阿米巴原虫黏附的显著活性。此外，α-倒捻子素具有去除隐形眼镜中棘阿米巴原虫黏附物的潜力，与市售多功能溶液（MPS）相似。SEM 研究证实，山竹花的粗提取物和α-倒捻子素是有效的隐形眼镜溶液，可在 24 小时内清除棘阿米巴原虫营养体。在 24 小时内，α-倒捻子素在低于 39μM 的浓度下对 Vero 细胞无毒。山竹花的粗提取物及其α-倒捻子素可作为治疗棘阿米巴感染的候选化合物，或作为隐形眼镜护理液，因为它们可用作天然产物的来源，以对抗棘阿米巴和与棘阿米巴原虫黏附相关的毒力因子。
