Tan Sijie, Tong Wen Han, Vyas Ajai
School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore.
Brain Behav Immun Health. 2020 Aug 11;8:100128. doi: 10.1016/j.bbih.2020.100128. eCollection 2020 Oct.
Neurotoxoplasmosis, also known as cerebral toxoplasmosis, is an opportunistic chronic infection caused by the persistence of parasite cysts in the brain. In wild animals, chronic infection is associated with behavioral manipulation evident by an altered risk perception towards predators. In humans, reactivation of cysts and conversion of quiescent parasites into highly invasive tachyzoites is a significant cause of mortality in immunocompromised patients. However, the current standard therapy for toxoplasmosis is not well tolerated and is ineffective against the parasite cysts. In recent years, the concept of dietary supplementation with natural products derived from plants has gained popularity as a natural remedy for brain disorders. Notably, urolithin-A, a metabolite produced in the gut following consumption of ellagitannins-enriched food such as pomegranate, is reported to be blood-brain barrier permeable and exhibits neuroprotective effects . In this study, we investigated the potential of pomegranate extract and urolithin-A as anti-neurotoxoplasmosis agents and . Treatment with pomegranate extract and urolithin-A reduced the parasite tachyzoite load and interfered with cyst development in differentiated human neural culture. Administration of urolithin-A also resulted in the formation of smaller brain cysts in chronically infected mice. Interestingly, this phenomenon was mirrored by an enhanced risk perception of the UA-treated infected mice towards predatory cues. Together, our findings demonstrate the potential of dietary supplementation with urolithin-A-enriched food as a novel natural remedy for the treatment of acute and chronic neurotoxoplasmosis.
神经型弓形虫病,也称为脑型弓形虫病,是一种由寄生虫囊肿在大脑中持续存在引起的机会性慢性感染。在野生动物中,慢性感染与行为操控有关,表现为对捕食者的风险感知改变。在人类中,囊肿重新激活以及静止的寄生虫转化为高度侵袭性的速殖子是免疫功能低下患者死亡的重要原因。然而,目前弓形虫病的标准治疗耐受性不佳,且对寄生虫囊肿无效。近年来,用植物来源的天然产物进行膳食补充的概念作为治疗脑部疾病的天然疗法越来越受欢迎。值得注意的是,尿石素A是食用富含鞣花单宁的食物(如石榴)后在肠道中产生的一种代谢产物,据报道它可透过血脑屏障并具有神经保护作用。在本研究中,我们研究了石榴提取物和尿石素A作为抗神经型弓形虫病药物的潜力。用石榴提取物和尿石素A处理可降低寄生虫速殖子载量,并干扰分化的人类神经培养物中的囊肿发育。给慢性感染的小鼠施用尿石素A还导致形成较小的脑囊肿。有趣的是,这种现象在经尿石素A处理的感染小鼠对捕食线索的风险感知增强中得到了体现。总之,我们的研究结果表明,用富含尿石素A的食物进行膳食补充作为治疗急性和慢性神经型弓形虫病的新型天然疗法具有潜力。