Saponins as cytotoxic agents: a review

Saponins are natural glycosides which possess a wide range of pharmacological properties including cytotoxic activity. In this review, the recent studies (2005–2009) concerning the cytotoxic activity of saponins have been summarized. The correlations between the structure and the cytotoxicity of both steroid and triterpenoid saponins have been described as well as the most common mechanisms of action

A triterpene saponin from "Lysimachia thyrsiflora L."

A triterpene saponoside (LTS-4) isolated from the underground parts of Lysimachia thyrsiflora L. was defined as 3-O-{β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α- L-arabinopyranosyl}-cyclamiretin A. Structure assignment was performed on the basis of spectroscopic data including homo- and heteronuclear 1D and 2D NMR (COSY, TOCSY, NOESY, HETCOR, HMBC and DEPT) and FAB-MS studies. The compound was tested in vitro for antimicrobial and cytotoxic activity

Incomplete degradation of lichen usnic acid and atranorin in Svalbard reindeer (Rangifer tarandus platyrhynchus)

Previous studies of Eurasian tundra reindeer (Rangifer tarandus tarandus) in Norway indicate that their rumen microbiota play a key role in degrading lichen secondary metabolites. We investigated the presence of usnic acid and atranorin in faecal samples from Svalbard reindeer (R. tarandus platyrhynchus). Samples were collected in Bolterdalen valley together with vegetation samples from the study site. The mesic tundra in this area was dominated by vascular plants (59% of vegetation cover). Bryophytes (16%) and lichens (25%) were also present. Qualitative and quantitative analyses of usnic acid and atranorin in lichen and faeces samples were performed using high-performance liquid chromatography. Contents of atranorin averaged 12.49 ± 0.41 mg g–1 in the thalli of Stereocaulon alpinum, while the average level of usnic acid was lowest in Cladonia mitis (12.75 ± 2.86 mg g–1) and highest in Flavocetraria cucullata (34.87 ± 0.47 mg g–1). Atranorin and usnic acid were detected in the faecal samples, averaging 0.41 ± 0.53 and 0.74 ± 1.11 (mean ± SD) mg g–1 dry matter, respectively. The presence of lichen secondary compounds in faeces from Svalbard reindeer shows that lichens are indeed included in their diet, although probably in small amounts because of depleted pastures. Contrary to previous findings in reindeer on mainland Norway, atranorin and usnic acid are not completely degraded or absorbed in Svalbard reindeer. To elucidate the mechanisms behind detoxification of lichen secondary compounds in reindeer, more research is needed on their respective rumen microbiomes and digestive enzymes

Saponins as cytotoxic agents : an update (2010-2018) : part I-steroidal saponins

Steroidal saponins are a group of glycosides widely distributed among monocotyledonous families. They exert a wide spectrum of biological effects including cytotoxic and antitumor properties which are the most studied. This review is an update of our previous paper-Saponins as cytotoxic agents (Podolak et al. in Phytochem Rev 9:425-474, 2010) and covers studies that were since published (2010-2018). In this paper we refer to steroidal saponins presenting results of cytotoxicity studies, mechanisms of action and structure-activity relationships