Antiplasmodial and antitumor activity of dihydroartemisinin analogs derived via the aza-Michael addition reaction

A comprehensive overview of Artemisinin and its derivatives as anticancer agents

Artemisinin is the crucial ingredient of artemisia annua, a traditional Chinese medicine used for the therapy of malaria in China for hundreds of years. In recent years, the anticancer properties of artemisinin and its derivatives have also been reported. This review has summarized the research and development of artemisinin and its derivatives as anticancer agents, which included both natural and synthetic monomers as well as their dimers. In addition, it highlights the antitumor effects of artemisinin and its derivatives after site-modification or after transformation to a nano-delivery system. Moreover, we have further explored their potential mechanisms of action and also discussed the clinical trials of ARTs used to treat cancer, which will facilitate in further development of novel anticancer drugs based on the scaffold of artemisinin.

Artesunate inhibits cell proliferation, migration, and invasion of thyroid cancer by regulating the PI3K/AKT/FKHR pathway

This study characterized the effects of artesunate on thyroid cancer and partially identified its related molecular mechanism. We determined the effect of artesunate on the proliferation of thyroid cancer cells using the MTT assay, cell colony formation experiments, and western blotting, and used flow cytometry to detect the apoptosis of cancer cells. Using a wound-healing assay, Transwell chamber experiments, and western blotting, we determined the effect of artesunate on cancer cell migration. By co-cultivating artesunate with the PI3K agonist, 740Y-P, we also partially identified the molecular mechanism. Artesunate significantly inhibited the growth, proliferation, migration, and invasion of thyroid cancer cells, and promoted the apoptosis of cancer cells. Using co-cultivation with a PI3K agonist, we found that the inhibitory effect of artesunate on cancer cells was mainly due to suppressing the PI3K/AKT/FKHR signaling pathway. By inhibiting the PI3K/AKT/FKHR signaling pathway, artesunate induced apoptosis of thyroid cancer cells and inhibited their proliferation and migration.

Structural and biological survey of 7-chloro-4-(piperazin-1-yl)quinoline and its derivatives

The 7-chloro-4-(piperazin-1-yl)quinoline structure is an important scaffold in medicinal chemistry. It exhibited either alone or as hybrid with other active pharmacophores diverse pharmacological profiles such as: antimalarial, antiparasitic, anti-HIV, antidiabetic, anticancer, sirtuin Inhibitors, dopamine-3 ligands, acetylcholinesterase inhibitors, and serotonin antagonists. In the presented review, a comprehensive discussion of compounds having this structural core is surveyed and illustrated.

Hybrid molecules with potential in vitro antiplasmodial and in vivo antimalarial activity against drug-resistant Plasmodium falciparum

Malaria is a tropical disease, leading to around half a million deaths annually. Antimalarials such as quinolines are crucial to fight against malaria, but malaria control is extremely challenged by the limited pipeline of effective pharmaceuticals against drug-resistant strains of Plasmodium falciparum which are resistant toward almost all currently accessible antimalarials. To tackle the growing resistance, new antimalarial drugs are needed urgently. Hybrid molecules which contain two or more pharmacophores have the potential to overcome the drug resistance, and hybridization of quinoline privileged antimalarial building block with other antimalarial pharmacophores may provide novel molecules with enhanced in vitro and in vivo activity against drug-resistant (including multidrug-resistant) P falciparum. In recent years, numerous of quinoline hybrids were developed, and their activities against a panel of drug-resistant P falciparum strains were screened. Some of quinoline hybrids were found to possess promising in vitro and in vivo potency. This review emphasized quinoline hybrid molecules with potential in vitro antiplasmodial and in vivo antimalarial activity against drug-resistant P falciparum, covering articles published between 2010 and 2019.

Novel dihydroartemisinin derivative DHA-37 induces autophagic cell death through upregulation of HMGB1 in A549 cells

Dihydroartemisinin (DHA) and its analogs are reported to possess selective anticancer activity. Here, we reported a novel DHA derivative DHA-37 that exhibited more potent anticancer activity on the cells tested. Distinct from DHA-induced apoptosis, DHA-37 triggered excessive autophagic cell death, and became the main contributor to DHA-37-induced A549 cell death. Incubation of the cells with DHA-37 but not DHA produced increased dots distribution of GFP-LC3 and expression ratio of LC3-II/LC3-I, and enhanced the formation of autophagic vacuoles as revealed by TEM. Treatment with the autophagy inhibitor 3-MA, LY294002, or chloroquine could reverse DHA-37-induced cell death. In addition, DHA-37-induced cell death was associated significantly with the increased expression of HMGB1, and knockdown of HMGB1 could reverse DHA-37-induced cell death. More importantly, the elevated HMGB1 expression induced autophagy through the activation of the MAPK signal but not PI3K-AKT–mTOR pathway. In addition, DHA-37 also showed a wonderful performance in A549 xenograft mice model. These findings suggest that HMGB1 as a target candidate for apoptosis-resistant cancer treatment and artemisinin-based drugs could be used in inducing autophagic cell death.

Application of the Triazolization Reaction to Afford Dihydroartemisinin Derivatives with Anti-HIV Activity

Artemisinin and synthetic derivatives of dihydroartemisinin are known to possess various biological activities. Post-functionalization of dihydroartemisinin with triazole heterocycles has been proven to lead to enhanced therapeutic potential. By using our newly developed triazolization strategy, a library of unexplored fused and 1,5-disubstituted 1,2,3-triazole derivatives of dihydroartemisinin were synthesized in a single step. All these newly synthesized compounds were characterized and evaluated for their anti-HIV (Human Immunodeficiency Virus) potential in MT-4 cells. Interestingly; three of the synthesized triazole derivatives of dihydroartemisinin showed activities with half maximal inhibitory concentration (IC₅₀) values ranging from 1.34 to 2.65 µM.

4-Aminoquinoline-hybridization en route towards the development of rationally designed antimalarial agents

Recent developments in 4-aminoquinoline-hybridization, as an attractive strategy for averting and delaying the drug resistance along with improvement in efficacy of new antimalarials, are described.

Antitumor activity of artemisinin and its derivatives: from a well-known antimalarial agent to a potential anticancer drug

Improvement of quality of life and survival of cancer patients will be greatly enhanced by the development of highly effective drugs to selectively kill malignant cells. Artemisinin and its analogs are naturally occurring antimalarials which have shown potent anticancer activity. In primary cancer cultures and cell lines, their antitumor actions were by inhibiting cancer proliferation, metastasis, and angiogenesis. In xenograft models, exposure to artemisinins substantially reduces tumor volume and progression. However, the rationale for the use of artemisinins in anticancer therapy must be addressed by a greater understanding of the underlying mechanisms involved in their cytotoxic effects. The primary targets for artemisinin and the chemical base for its preferential effects on heterologous tumor cells need yet to be elucidated. The aim of this paper is to provide an overview of the recent advances and new development of this class of drugs as potential anticancer agents.