ORIGINAL ARTICLE Moringa oleifera Extracts and Praziquantel Combination: Bioavailability in Rats and Cysticidal Activity in a Murine Model Francisca Palomares-Alonso 1 & Helgi Jung 1,2 & Guadalupe Concepción Vidal-Cantú 3 & Irma Susana Rojas-Tomé 1 & Dinora F. González-Esquivel 4 & Verónica Pérez De la Cruz 4 & Iliana González Hernández 1 & Guadalupe Palencia Hernández 5 & Francisca Pérez-Severiano 6 & Nelly Castro 1,2 Received: 5 November 2019 /Accepted: 25 December 2019 # Sociedade Brasileira de Farmacognosia 2020 Abstract Praziquantel is an anthelmintic drug extensively used that shows a low oral bioavailability. Various approaches have been used in order to increase the plasma levels of praziquantel, including the co-administration with Cytochrome P450 inhibitors. Moringa oleifera Lam., Moringaceae, is an appreciated plant by its nutritional value and is widely used in traditional medicine. It contains a number of potential active compounds including flavonoids and phenolic components that can alter Cytochrome P450 activity. The aim of this work was to evaluate the effect of M. oleifera leaf and seed extracts on the praziquantel bioavailability and assess its in vivo effect on a Taenia crassiceps murine model. A validated method by high-performance liquid chromatography with diode array detection for determination of praziquantel plasma levels was used. The results showed that after the oral adminis- tration of praziquantel with M. oleifera, the maximum plasma concentration of praziquantel increased by 2.4- and 5.6-fold with leaf and seed extracts respectively. The area under the curve values from time 0 to 120-min ratios between the combinations and praziquantel alone were 1.8 and 3.6 for leaf and seed extracts, respectively. Cysticidal activity of the combination of praziquantel and seed extract was significantly greater than the administration of praziquantel alone. Keywords Pharmacokinetics . Bioavailability . Anthelmintic drug . Natural products . Interaction . Cysticidal activity Introduction Praziquantel (PZQ), known as Biltricide (brand name) among others, is one of the few available drugs for the treatment of parasitic infections by helminths in humans (Chai 2013; da Silva et al. 2017). The search for treatment alternatives is impor- tant, since parasitic diseases are a major health problem, partic- ularly in tropical and subtropical poor countries (Bustinduy et al. 2016; Senghor et al. 2016). PZQ shows poor solubility and high permeability (BCS II drug, Biopharmaceutical Classification System) as well as extensive first-pass metabolism, mainly by Cytochrome 3A4 (CYP), which may lead to drug-drug interac- tions that in some cases could be beneficial to enhance therapeu- tic efficacy and with the possibility to reduce the cost of therapy. PZQ bioavailability increases with inhibitors of CYP3A4 as ketoconazole, miconazole, cimetidine, and rifampicin (Jung et al. 1997; Ridtitid et al. 2007). Another approach that has been studied in order to raise plasma levels and clinical effect is the concomitant administration with food (Bonate et al. 2018). The use of herbal medicines has been improved, as a result of public interest, as a complementary, or as an alternative Electronic supplementary material The online version of this article (https://doi.org/10.1007/s43450-020-00058-w) contains supplementary material, which is available to authorized users. * Nelly Castro nnct@unam.mx 1 Laboratorio de Neuropsicofarmacología, Instituto Nacional de Neurología y Neurocirugía “Manuel Velasco Suárez”, Mexico City, Mexico 2 Facultad de Química, Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, Mexico City, Mexico 3 Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados, Mexico City, Mexico 4 Laboratorio de Neurobioquímica y Conducta, Instituto Nacional de Neurología y Neurocirugía “Manuel Velasco Suárez”, Mexico City, Mexico 5 Laboratorio de Neuroinmunología, Instituto Nacional de Neurología y Neurocirugía “Manuel Velasco Suárez”, Mexico City, Mexico 6 Laboratorio de Neurofarmacología Molecular y Nanotecnología, Instituto Nacional de Neurología y Neurocirugía “Manuel Velasco Suárez”, Mexico City, Mexico Revista Brasileira de Farmacognosia https://doi.org/10.1007/s43450-020-00058-w