Abstract Bacterial dysbiosis is a recognized risk of inappropriate antimicrobial treatment of infectious diarrhoea, and its link to gastrointestinal carcinogenesis is increasingly discussed. (Iso)quinolines are plant alkaloids that serve as scaffolds for several antibiotic and anticancer drugs due to their broad biological activities. Moreover, some studies suggest they may have a minimal or non-disruptive impact on the indigenous gut microbiota. Present review evaluates the previously described bioactive properties of 258 plant (iso)quinolines against intestinal diarrheagenic/probiotic bacteria and/or cancer/normal cells in vitro (e.g., minimum inhibitory concentrations, half maximal inhibitory concentrations), based on which it performs structure–activity relationship analyses for each of the involved structural type. Furthermore, it analyses how the abundance of the most active alkaloids in plants relates to their ethnopharmacological importance and traditional use. The results showed that (iso)quinolines of benzophenanthridine, indolo(iso)quinoline, and furoquinoline structures exhibit strong antibacterial and anticancer potential against multiple intestinal targets, whereas specific structural features of Amaryllidaceae isoquinolines, simple quinolines, and protoberberines appear to enhance selectivity by exerting lower effects on normal cells and/or probiotic bacteria. The chemotaxonomic assessment identified several plant genera within Rutaceae, Papaveraceae and other mainly Ranunculales families as important natural sources of these compounds, many of which are traditionally used in treating gastrointestinal disorders. Future research should include (iso)quinolines with identified structural features in broader in vitro assays, advanced microbiota models, in vivo systems, toxicological studies, and detailed phytochemical analyses of their plant sources to better clarify their safety and therapeutic relevance.

Abstract Neglected Tropical Diseases (NTDs) are a group of parasitic diseases that are a major global health issue, particularly in developing countries. Natural products continue to be an area of ac-tive research and may offer new and effective treatments for NTDs. In this sense, Amaryllidaceae species have been studied for their potential antiparasitic activity, such as trypanosomiasis, leish-maniasis and others. A review on Web of Science and Scopus database was carried out to examines those species of the family, which have hitherto been examined for antiparasitic activity at last seven years. In this study, a total of 22 experimental articles related to the theme were identified out of the 444 found in the search platform. Overall, the study listed more than 40 Amaryllidaceae alkaloids which displayed activities including antileishmanial, antiplasmodial, anti-Trichomonas, anti-Trypanosoma, and antiviral effects. A virtual screening study of the Amaryllidaceae alkaloid database was also conducted aiming to find promising molecules with active potential against NTD-causing parasites, Leishmania infantum , Leishmania amazonensis , Trypanosoma cruzi , and Schistosoma mansoni . This library of compounds was derived from a recent review that en-compassed 636 Amaryllidaceae alkaloids. After the in-silico study, it was possible to identify three alkaloids (zephycarinatine B, zephycarinatine H, and zephygrantine E) with multitarget active potential. These findings highlight the continued importance of these plant species as a source of compounds for studying NTD’s.