Toxoplasma gondii is a protozoan parasite that can cause severe and debilitating diseases, especially in immunocompromised individuals. The available treatment is based on drugs that have low efficacy, high toxicity, several adverse effects, and need long periods of treatment. Thus, the search for therapeutic alternatives is urgently needed. Biogenic silver nanoparticles (AgNp-Bio) have been associated with several biological effects, as antiproliferative, pro-apoptotic, antioxidant, antiviral, antifungal, and antiprotozoal activity. Thus, the objective was evaluating AgNp-Bio effect on HeLa cells infected with T. gondii (RH strain). First, nontoxic AgNp-Bio concentrations for HeLa cells (1.5 – 6 µM) were determined, which were tested on cells infected with T. gondii. A significant reduction in infection, proliferation, and intracellular parasitic load was observed, also an increase in ROS and IL-6. Additionally, the evaluation of the action mechanisms of the parasite showed that AgNp-Bio acts directly on tachyzoites, inducing depolarization of the mitochondrial membrane, ROS increase, and lipid bodies accumulation, as well as triggering an autophagic process, causing damage to the parasite membrane, and phosphatidylserine exposure. Based on this, it was inferred that AgNp-Bio affects T. gondii by inducing immunomodulation and microbicidal molecules produced by infected cells, and acts on parasites, by inducing autophagy and apoptosis.

弓形虫是一种原生动物寄生虫，可引起严重和使人衰弱的疾病，尤其是在免疫功能低下的个体中。现有的治疗方法是基于疗效低、毒性大、副作用多且需要长期治疗的药物。因此，迫切需要寻找治疗替代方案。生物银纳米粒子 (AgNp-Bio) 与多种生物效应有关，如抗增殖、促凋亡、抗氧化、抗病毒、抗真菌和抗原生动物活性。因此，目标是评估 AgNp-Bio 对感染弓形虫（RH 株）的HeLa 细胞的影响。首先，确定了 HeLa 细胞 (1.5 – 6 µM) 的无毒 AgNp-Bio 浓度，并在感染了弓形虫的细胞上进行了测试. 观察到感染、增殖和细胞内寄生虫负荷显着减少，ROS 和 IL-6 也增加。此外，对寄生虫作用机制的评估表明，AgNp-Bio直接作用于速殖子，引起线粒体膜去极化、ROS增加和脂质体积累，并引发自噬过程，对寄生虫膜造成损伤。和磷脂酰丝氨酸暴露。基于此推断，AgNp-Bio通过诱导受感染细胞产生的免疫调节和杀微生物分子来影响弓形虫，并通过诱导自噬和细胞凋亡作用于寄生虫。