In silico and In vivo Toxicological Evaluation of Cissampelos Sympodialis Secondary Metabolites in Rattus Norvegicus.

Cissampelos sympodialis is a plant in northeastern Brazil used by the populace for treating respiratory diseases. Several studies have shown that ethanol leaf extracts have immunomodulatory and anti-inflammatory activities. Infusions are widely used, popular, and an ancient technique in traditional medicine, using hot water alone as the means of extraction. This study aimed to investigate acute toxicological potential of leaf infusions of Cissampelos sympodialis, when applied orally at a dose of 2000mg/kg to Rattus norvegicus, combined with an in silico study of 117 alkaloids present in the Cissampelos genus; five (5) of which were determined to have high toxicity (21, 8, 93, 32 and 88), and five (5) having both low toxicity (57, 77, 28, 25 and 67) and low liver metabolism. The in vivo toxicological evaluation showed that male water consumption decreased, and the feed intake decreased in both sexes. Yet, the figures as to change in weight gain of the animals were not statistically sufficient. As for the biochemical parameters, there was an increase in urea, and decreases in uric acid and AST in males. In females, there was a decrease in albumin and globulin which consequently leads to a total protein decrease. Despite biochemical changes suggestive of kidney damage, the histological sections revealed no kidney or liver changes. The results therefore indicate that despite presenting alkaloids which may be toxic, the genus Cissampelos, or leaf infusions of Cissampelos sympodialis, when applied orally at a dose of 2000mg/kg present low toxicity.

Enzymatic Targets in Trypanosoma brucei.

One of the most neglected disease is the Sleeping sickness or Human African Trypanosomiasis (HAT), which is mostly restricted to poor regions of Africa. The disease is caused by parasitic infection with Trypanosoma brucei (T. brucei), and is acquired through the bite of the tsetse fly. In the first stage of the disease, the parasite is in the blood, but in stage 2, the infective form reaches the brain, causing great weakness and death. The few existing drugs against this infection, are highly toxic, and can cause the emergence of resistant forms of the parasite. Also, these drugs are not readily available. New drugs are needed. Many researchers are investigating new enzyme targets for the parasite, searching for more efficient and selective inhibitors that are capable to cause the parasite death with less toxicity to the host. Trypanothione reductase, farnesyl diphosphate synthase, 6-phospho-gluconate dehydrogenase, and UDP 4'-galactose epimerase are some of the enzymes involved in the studies reported on this review. In addition, we have applied ligandbased- virtual screening, using Random Forest associated with structure-based-virtual screening (docking), to a small dataset of 225 alkaloids from the Menispermaceae family (in-house data bank). The aim of this study is to select structures with potential inhibitory activity against trypanothione reductase from Trypanosoma brucei. The computer-aided drug design study selected certain alkaloids that might be worth further investigation.