Pharmacokinetics and cytotoxic study of euphol from Euphorbia umbellata (Bruyns) Pax latex.

BACKGROUND: Medicinal plants are an important source to identify new active pharmaceutical compounds. Traditionally, the sap of Euphorbia umbellata is widely used to treat cancer and inflammatory conditions. These effects have been attributed to the presence of terpenes and phenolic compounds in the extracts of this plant. Euphol, a tetracyclic triterpene alcohol, is one of the major compounds present in Euphorbia species, and some biological activities have been attributed to this compound. PURPOSE: This study aimed to evaluate the in vitro cytotoxicity of euphol against Jurkat, HL-60, K-562, B16F10, and HRT-18 cells lines, as well as the biological stability, distribution, metabolism properties in vitro, and the determination of the concentration of euphol in the plasma and liver of rats. METHODS: The MTT reduction assay was used to evaluate the cytotoxicity of euphol against cancer cell lines, and the selectivity index, the morphology and cell cycle assays to evaluate the death mechanisms in K-562 and B16F10 lineages. UHPLC-MS was applied for the in vivo evaluation of the concentration of euphol in plasma and liver, and in vitro metabolic stability in human liver microsomes and S9 fraction, plasma protein binding, and stability in simulated gastric and intestinal fluids assays. CONCLUSIONS: This study demonstrated that euphol exhibited cytotoxic effects against a variety of cancer cells lines, selectivity against leukemia and possibly, the mechanism involved is apoptosis. The evaluation of stability, distribution, and metabolism properties showed that euphol was unstable in gastric and intestinal fluids, presenting moderate plasma protein binding with two hours elimination half-life and possible phase II liver metabolism. All the results suggested that further studies could be developed to prove the viability of euphol as an anticancer agent.

Euphorbia umbellata bark extracts – an in vitro cytotoxic study

ABSTRACT Euphorbia umbellata (Pax) Bruyns, Euphorbiaceae, is commonly used in folk medicine of southern Brazil to treat several kinds of cancer. The latex (part of the plant used for this purpose) is mixed with water and taken as treatment; but this matrix contains toxic potential related to the presence of some phorbol type diterpenes. So the aim of this study was to evaluate the cytotoxicity of the crude extract of the bark of E. umbellata and its fractions (Hex, CHCl3, EtOAc and MeOH) using in vitro assay (applying Jurkat cells line). A preliminary cytotoxic study (MTT reduction, trypan blue exclusion and DNA quantification assays) was executed to identify the most active material. The CHCl3 fraction displayed the highest activity and was selected for further investigation of any cytotoxic mechanism and evaluation of chemical composition; flow cytometry, Acridine orange and Hoechst 33342 staining experiments and Gas chromatography–mass spectrometry analysis were applied to achieve these results. This fraction demonstrated the best cytotoxic results against Jurkat cells line with IC50 of 29.00 ± 1.49, 10.06 ± 1.48 and 4.83 ± 2.25 µg/ml for 24, 48 and 72 h of experiment, respectively (trypan blue exclusion). The mechanism responsible for this action can be associated with the promotion of cell cycle arrest and apoptosis. The two main classes of compounds present in the CHCl3 fraction are steroids and triterpenes. Further, phytochemical studies with this fraction need to be evaluated, to try isolating these substances and establishing a more detailed cytotoxic study against Jurkat cells.

Effect of fish oil supplementation for two generations on changes of lymphocyte function induced by Walker 256 cancer cachexia in rats.

Fish oil supplementation has been shown to improve the cachectic state of tumor-bearing animals and humans. Our previous study showed that fish oil supplementation (1 g per kg body weight per day) for 2 generations had anticancer and anticachetic effects in Walker 256 tumor-bearing rats as demonstrated by reduced tumor growth and body weight loss and increased food intake and survival. In this study, the effect of fish oil supplementation for 2 generations on membrane integrity, proliferation capacity, and CD4/CD8 ratio of lymphocytes isolated from mesenteric lymph nodes, spleen, and thymus of Walker 256 tumor-bearing animals was investigated. We also determined fish oil effect on plasma concentration and ex vivo production of cytokines [tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-4 (IL-4), IL-6, and IL-10]. Lymphocytes from thymus of tumor-bearing rats presented lower viability, but this change was abolished by fish oil supplementation. Tumor growth increased proliferation of lymphocytes from all lymphoid organs, and fish oil supplementation abolished this effect. Ex vivo production of TNF-alpha and IL-6 was reduced in supplemented animals, but IL-4 and IL-10 secretion was stimulated in both nontumor and tumor-bearing rats. IL-10 and IFN-gamma plasma levels was also decreased in supplemented animals. These results suggest that the anticachetic effects of fish oil supplementation for a long period of time (2 generations) in Walker 256 tumor-bearing rats may be associated to a decrease in lymphocyte function as demonstrated by reduced viability, proliferation capacity, and cytokine production.