Developmental toxicity, antioxidant, and marker enzyme assessment of swertiamarin in zebrafish (Danio rerio).

A secoiridoid glycoside called swertiamarin has been widely used as a herbal medicine for many decades. In particular, swertiamarin from the Enicostema axillare herb has been used as a multipurpose drug to treat innumerable health problems. As this medicine is consumed orally, its toxicity level should be determined. To examine the safety of this compound, toxicology work was done in zebrafish, and this is the first report to describe swertiamarin toxicity in zebrafish. Zebrafish embryos were used in this swertiamarin toxicity study, and morphological changes were observed. Further, the compound was also studied in adult zebrafish to determine the impact of the compound on the fish liver. Enzyme profiling with superoxide dismutase, glutathione peroxidase, catalase, reduced glutathione levels, glutathione S-transferase, lactate dehydrogenase, glutamic oxaloacetic transaminases, lipid peroxidation, Na+ /K+ -ATPase, and glutamic pyruvic transaminases) was evaluated (p ≤ 0.05). Results suggest that swertiamarin is a safe drug only at a low concentration (40 µM). This study also shows that even herbal medicinal compounds may be toxic to humans at higher dosages. Hence, irrespective of whether a drug is synthetic or natural, it needs to be tested for its toxicity before use in humans.

Hepatoprotective activity assessment of amino acids derivatives of picroside I and II.

Picrorhiza kurroa has a long medicinal history as a traditional medicinal plant in China and India that is widely used in clinical treatments. It is a common treatment for liver diseases, fever, diarrhoea, indigestion, and some other diseases. Modern pharmacological studies proved that P. kurroa rhizomes have high levels of picroside I and II, which were identified as main constituents with anti-inflammatory and hepatoprotective activities. In our study, we used picroside I and II as the lead compounds to generate derivatives by reactions with Boc-valine or Boc-proline, which underwent dehydration and condensation with the hydroxyl groups in the lead compounds in the presence of coupling reagent N,N'-dicyclohexylcarbodiimide. We synthesized 11 derivatives and examined their hepatoprotective effects in vitro by assessing the proliferation rates of H2 O2 -exposed HepG2 cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. We found that some derivatives promoted higher proliferation rates in HepG2 cells than the natural compounds before derivatization, suggesting that those derivatives possessed an improved hepatoprotective capacity. The novel derivatization strategy for picrosides had the additional benefit that the esterification of their hydroxyl groups created derivatives not only with increased stability but also with improved pharmacokinetic properties and potentially prolonged half-life.