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Effects of Zuccagnia punctata extracts and their flavonoids on the function and expression of ABCB1/P-glycoprotein multidrug transporter.

J Ethnopharmacol. 2012 Oct 18;

Authors: Chieli E, Romiti N, Catiana Zampini I, Garrido G, Inés Isla M


ETHNOPHARMACOLOGICAL RELEVANCE: Zuccagnia punctata extracts (ZpE) are used in ethnomedicine as antimicrobial and anti-inflammatory drugs. The pharmacological properties of ZpE and their polyphenolic components suggest that they may be used as potential modulators on the P-glycoprotein (P-gp) multidrug transporter. P-gp is well known for its role in the acquired drug resistance by tumors following chemotherapy, causing a low drug bioavailability by extruding them out of the cells. AIM OF STUDY: To evaluate the effects of ZpE and three of their phenolic components: 7-hydroxyflavanone (HF), 3,7-dihydroxyflavone (DHF) and 2',4'-dihydroxychalcone (DHC) on P-gp activity and expression. MATERIAL AND METHODS: The effects of natural products on ABCB1/P-gp function and expression were evaluated by R-123 accumulation assay and western blot analysis using HK-2 cells as experimental model. The ABCB1 mRNA content was determined by SQRT-PCR. RESULTS: The accumulation of R-123 in HK-2 cells was significantly increased by ZpE and DHF, and to a lesser extent by DHC, indicating their roles on the efflux transporter activity. However, HF did not show any effect. HK-2 cells maintained in the presence of ZpE or DHF for 72h, showed an increase in P-gp expression whereas activity was unchanged or decreased. No changes were observed in ABCB1 mRNA content. Furthermore, in these assay conditions, more sensibility of HK-2 cells to the cytotoxic action of cyclosporine A (P-gp substrate) was observed. CONCLUSION: These results may suggest an impact of Zuccagnia punctata and some of its components on the pharmacokinetics of drugs that are P-gp substrates, as well as a potential role on multidrug resistance modulation.

PMID: 23085022 [PubMed - as supplied by publisher]