Rigamonti Giulia, Veronesi Fabrizia, Chiaradia Elisabetta, Gosten-Heinrich Petra, Müller Antonia, Brustenga Leonardo, de Angelis Stefano, Tognoloni Alessia, De Santo Riccardo, Klotz Christian, Lalle Marco
Department of Veterinary Medicine, University of Perugia, via San Costanzo 4, Perugia, Italy.
Department of Infectious Diseases, Unit 16 Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Seestrasse 20, Berlin, Germany.
Int J Parasitol Drugs Drug Resist. 2025 Apr;27:100583. doi: 10.1016/j.ijpddr.2025.100583. Epub 2025 Jan 22.
Giardia duodenalis is a widespread intestinal protozoan that affects mammals, including humans. Symptoms can range from being subclinical to causing severe abdominal pain and diarrhoea. Giardiasis often requires repeated treatment with synthetic drugs like metronidazole. In recent years, treatment failures in clinical cases involving nitroimidazoles have been increasingly reported. Consequently, identifying therapeutic alternatives is necessary. Medicinal plants have traditionally been used as antiparasitic compounds, but systematic evaluation under controlled experimental conditions is often lacking. Here, we evaluated the in vitro efficacy of Tabebuia avellanedae dry and hydroalcoholic extracts, as well as one of its active compounds, β-lapachone, as potential treatment against G. duodenalis infection. We observed effective antigiardial activity for all tested compounds, with β-lapachone exhibiting lower IC values than metronidazole. Cytotoxic effects often limit therapeutic concentration windows of opportunity, and choosing an informative model to assess them is not straightforward. In the present case, only T. avellanedae hydroalcoholic extract showed no cytotoxicity on tumoral human intestinal Caco-2 cell line, and only a trend of inhibition when tested on canine epithelial kidney MDCK cells. To introduce a more physiological test system, we used in vitro G. duodenalis infection experiments in a trans-well set-up using organoid derived monolayers (ODM) to assess at the same time drug efficacy against the parasite and safety on primary human intestinal epithelia, a likely surrogate for in vivo conditions. Our studies using this model point towards the potential therapeutic opportunity for non-systemic applications of T. avellanedae extracts and a relevant ingredient of these, β-lapachone. The data suggest that ODM co-cultures with G. duodenalis are suitable for testing antigiardial compounds, providing a more informative in vitro model before progressing to in vivo tests.
十二指肠贾第虫是一种广泛存在的肠道原生动物，可感染包括人类在内的哺乳动物。症状从亚临床状态到引起严重腹痛和腹泻不等。贾第虫病通常需要用甲硝唑等合成药物反复治疗。近年来，涉及硝基咪唑类药物的临床治疗失败案例报道越来越多。因此，有必要确定其他治疗方法。药用植物传统上被用作抗寄生虫化合物，但往往缺乏在可控实验条件下的系统评估。在此，我们评估了榄绿微甘菊干燥提取物和水醇提取物及其活性成分之一β-拉帕醌对十二指肠贾第虫感染的潜在治疗效果。我们观察到所有测试化合物均具有有效的抗贾第虫活性，β-拉帕醌的半数抑制浓度值低于甲硝唑。细胞毒性效应常常限制治疗浓度窗口，选择一个能提供信息的模型来评估它们并非易事。在本案例中，只有榄绿微甘菊水醇提取物对人肿瘤性肠Caco-2细胞系无细胞毒性，在犬肾上皮MDCK细胞上测试时只有抑制趋势。为了引入一个更具生理学意义的测试系统，我们在一个跨膜装置中使用体外十二指肠贾第虫感染实验，利用类器官衍生单层（ODM）同时评估药物对寄生虫的疗效以及对原代人肠上皮细胞的安全性，原代人肠上皮细胞可能是体内情况的替代物。我们使用该模型的研究表明，榄绿微甘菊提取物及其相关成分β-拉帕醌在非全身应用方面具有潜在治疗机会。数据表明，与十二指肠贾第虫共培养的ODM适合测试抗贾第虫化合物，在进行体内试验之前提供了一个更具信息性的体外模型。
