Artesunate reduces proliferation, interferes DNA replication and cell cycle and enhances apoptosis in vascular smooth muscle cells

In Vitro Assessment of Cytoprotective Effects of CANOVA against Cell Death Induced by the Anti-malarial Artesunate - A Preliminary Experiment

BACKGROUND

 Artesunate (ATS) is a semi-synthetic compound derived from artemisinin, which is widely accepted in the treatment of malaria. However, there is evidence that ATS, under certain in vitro conditions, induces several impairments to normal cell functions. Canova (CA) is a Brazilian homeopathic formulation indicated for patients with depressed immune system. CA shows both in vitro and in vivo protective effects against mutagenic/carcinogenic compounds. Therefore, we aimed to assess in vitro the cytoprotective effects of CA against the cytotoxicity of ATS in Vero cells.

METHODS

 Viability of Vero cells exposed to ATS was assessed by MTT assay, whereas the anti-cytotoxic effect of CA was evaluated by apoptosis and necrosis quantification with fluorescent dyes.

RESULTS

 After 24 hours of ATS treatment, a reduction in cell viability was observed at 32 and 64 µg/mL, the latter being statistically significant (p < 0.05) in relation to the negative control. The concentration of 64 µg/mL was chosen for the subsequent experiments. ATS significantly induced both apoptosis and necrosis in Vero cells in relation to controls (p < 0.01). We also observed a statistically significant decrease in the number of apoptotic cells observed in the CA 16% + ATS co-treatment compared with ATS treatment (p < 0.01). Treatment with CA alone also had no influence on either type of cell death.

CONCLUSION

 Our results demonstrated that ATS is cytotoxic in the assessed conditions. However, such cytotoxicity was attenuated when the cells were treated simultaneously with ATS and CA.

The Potential Therapeutic Effects of Artesunate on Stroke and Other Central Nervous System Diseases

Artesunate is an important agent for cerebral malaria and all kinds of other severe malaria because it is highly efficient, lowly toxic, and well-tolerated. Loads of research pointed out that it had widespread pharmacological activities such as antiparasites, antitumor, anti-inflammation, antimicrobes activities. As we know, the occurrence and development of neurological disorders usually refer to intricate pathophysiologic mechanisms and multiple etiopathogenesis. Recent progress has also demonstrated that drugs with single mechanism and serious side-effects are not likely the candidates for treatment of the neurological disorders. Therefore, the pluripotent action of artesunate may result in it playing an important role in the prevention and treatment of these neurological disorders. This review provides an overview of primary pharmacological mechanism of artesunate and its potential therapeutic effects on neurological disorders. Meanwhile, we also briefly summarize the primary mechanisms of artemisinin and its derivatives. We hope that, with the evidence presented in this review, the effect of artesunate in prevention and curing for neurological disorders can be further explored and studied in the foreseeable future.

In vitro evaluation of the genotoxic and cytotoxic effects of artesunate, an antimalarial drug, in human lymphocytes

Artesunate is one of the main antimalarial drugs used in several countries. It is a semisynthetic compound derived from artemisinin, a substance extracted from the Chinese plant, Artemisia annua L. Despite the widespread use of artesunate as an antimalarial drug, there is a lack of data regarding its genotoxic effects in human lymphocytes. Therefore, in this study, we used the comet assay and micronucleus test to evaluate the possible genotoxic effects of artesunate in cultured human lymphocytes. In addition, cell death by necrosis and apoptosis was also assessed. Cells exposed to different concentrations of artesunate showed a significant concentration-dependent increase (P < 0.05) in DNA damage index and micronuclei frequency. A significant increase in the frequency of apoptotic and necrotic cells was also observed. Our results showed that artesunate is a genotoxic and cytotoxic compound in cultured human lymphocytes.

Pro-apoptotic effects of antimalarial drugs do not affect mature human erythrocytes

Malaria is an important public health problem worldwide, representing also an obstacle for the development of the countries, mainly in the African continent. Since no effective vaccine has been developed yet, early diagnosis and prompt treatment are the main strategy to control malaria transmission. Many of the drugs used for malaria treatment have the ability to induce apoptosis in different cell types. In addition, apoptosis has also been identified in enucleated cells. The present work is aimed, therefore, to evaluate the pro-apoptotic aptness of chloroquine, quinine, artemisinin and mefloquine on mature erythrocytes by flow cytometry through the detection of cell shrinkage and phosphatidylserine exposure at the cell surface-hallmarks of apoptosis. Although we observed that known apoptosis inducer, such as ionomycin, had led to erythrocyte apoptosis, we were not able to detect any pro-apoptotic effect of the studied antimalarial drugs on these cells. We conclude that chloroquine, quinine, artemisinin and mefloquine may not be able to induce apoptosis in erythrocytes and, therefore, do not seem to contribute to malaria associated erythrocyte destruction and anemia.