In African countries, cancer not only is a growing problem, but also a challenge because available funding and resources are limited. Therefore, African medicinal plants play a significant role in folk medicine and some of them are traditionally used for the treatment of cancer. The high mortality rate and adverse effects associated with cancer treatments have encouraged the search for novel plant-based drugs, thus, some African plants have been studied in recent years as a source of molecules with proven cytotoxicity. This review aims to discuss the cytotoxic activity, in vitro, of African plant crude extracts against cancer cell lines. For the period covered by this review (2017–2021) twenty-three articles were found and analyzed, which included a total of 105 plants, where the main cell lines used were those of breast cancer (MCF-7 and MDA-MBA-231) and colorectal cancer (HCT-116 and Caco-2), which are among the most prevalent cancers in Africa. In these studies, the plant crude extracts were obtained using different solvents, such as ethanol, methanol, or water, with variable results and IC₅₀ values ranging from 200 µg/mL. Water is the preferred solvent for most healers in African countries, however, in some studies, the aqueous extracts were the least potent. Apoptosis and the induction of cell cycle arrest may explain the cytotoxic activity seen in many of the plant extracts studied. Considering that the criteria of cytotoxicity activity for the crude extracts, as established by the American National Cancer Institute (NCI), is an IC₅₀ < 30 μg/mL, we conclude that many extracts from the African flora could be a promising source of cytotoxic agents.

Quinolines have been an interest of study for a few decades due to the importance of this system in natural and pharmaceutical products. Since their discovery in the nineteenth century, many medicinal properties have been found for quinoline compounds. Firstly, as an anti-parasitic agent against malaria and then against many other diseases, such as, other parasitic infections, HIV, bacterial infections and cancer. Consequently, many synthetic methods have been developed to afford the quinoline ring. In this review we look back at traditional methods and look forward to the most recent and promising "green" methods for the synthesis of quinolines. Also, we review the newest advances in therapeutic compounds based on the quinoline skeleton for the treatment of parasitic and cancer diseases and the most recent applications of quinoline derivatives in drug delivery systems.

The sea is a rich source of biological active compounds, among which terpenyl-quinones/hydroquinones constitute a family of secondary metabolites with diverse pharmacological properties. The chemical diversity and bioactivity of those isolated from marine organisms in the last 10 years are summarized in this review. Aspects related to synthetic approaches towards the preparation of improved bioactive analogues from inactive terpenoids are also outlined.