Pyrrolizidine alkaloids enhance alcohol-induced hepatocytotoxicity in vitro in normal human hepatocytes

Show simple item record Neuman, M.G. Cohen, L.B. Steenkamp, Vanessa 2017-08-30T12:11:24Z 2017-08-30T12:11:24Z 2017-03
dc.description.abstract OBJECTIVE : Herbal remedies containing pyrrilidozine alkaloids (PA)s can induce liver damage, including hepato-sinusoidal obstruction syndrome (HSOS) or veno-occlusive liver disease (VOD). Some individuals misusing alcohol consume also teas and/or herbal remedies containing PA. The interaction or additive toxicity of alcohol to PA toxicity needs to be addressed. The objectives of this study are 1) to review the scientific literature on the PA-induced liver toxicity; 2) identify possible mechanism(s) involved in PA-induced hepatocytotoxicity in the presence or absence of ethanol (EtOH) in vitro in normal human hepatocytes (NHH) in primary culture. To respond to the first objective, we systematically search all the literature engines (PubMed, Google Scholar) for liver induced damage due to PAs and summarize the results in an introductory systematic review. ORIGINAL ARTICLE EXPERIMENTAL DESIGN AND METHODS : Cells were exposed to one dose of 100 mmol/L EtOH for 24 hrs and to 2 doses of 100 mmol/L EtOH for consecutive 24 hrs periods, in the presence or absence of PAs (10 mg/mL), or the caspase-3 inhibitor IDN-1965 (50 μmol/L). Cells were analyzed for apoptosis by light microscopy, immuno-histochemistry, measuring cytokeratin-18 fragmentation, and transmission electron microscopy (TEM) (6000 cells/ treatment). Cytotoxicity was determined using succinate dehydrogenase (SDH) activity, an enzyme specific to the mitochondria. RESULTS : In NHH cells, a 100 mmol/L dose of Et-OH resulted in 22±2.5 apoptosis (p<0.001 vs. control). Two consecutive doses of 100 mmol/L Et-OH for 24 hrs each caused 36±3.0% apoptosis (p<0.001 vs. control and p<0.05 vs. one dose Et- OH). Pre-treatment with 50 μmol/L caspase inhibitor significantly reduced Et-OH-induced apoptosis [12±1.5% in 100 mmol/L (p<0.05) and 20±4.0% in 2×100 mmol/L (p<0.001)]. In addition, pre-treatment with 50 μmol caspase inhibitor in cells treated with PA + EtOH reduced apoptosis significantly (vs. non-exposed to caspase-inhibitor): Δ -22±3.0 % (p<0.05). HPC significantly decreased apoptosis compared to conditions lacking this supplementation in cells treated with EtOH-exposed cells present ballooning, Mallory bodies, changes in mitochondrial cristae and apoptosis by TEM. Pre-treatment with 50 μmol caspase inhibitor significantly reduced 100 mmol/L EtOH-induced (one dose) in NHH by 14±0.5% (p<0.05) compared to cells not exposed to the caspase-inhibitor. In cells treated concomitantly with PA and EtOH 100 mM Mallory-bodies and apo-necrotic cells have been observed. Pre-treatment with 50 μmol caspase inhibitor reduced the mitochondrial damage. A significant depletion in glutathione (GSH) was observed in Et-OH treated cells after 1 and 2 treatments (p<0.001 vs. control). Treatment with E t-OH enhanced PA-induced GSH-depletion and resulted in a significant increase in PA-induced cytotoxicity (p<0.001 vs. Et-untreated cells). Exposure to EtOH increased the cell culture media levels of the pro-inflammatory cytokine TNF. PA + EtOH-treated cells increased TNF-α levels in media compared to EtOH alone [86±8 vs. 53±5 pg/mL in cells exposed to 100 mmol/L EtOH (p<0.05) and 218±14 vs. 179±8 pg/mL in cells exposed to 2×100 mmol/L EtOH (p<0.05)]. CONCLUSIONS : PA up-regulates EtOH-induced hepatocytotoxicity by inducing the inflammatory cytokines and enhancing the apoptotic effects of ethanol. There is a need for monitoring herbal medicine in order to optimize traditional medicine use and maximize the clinical benefits. Additionally, there is necessary to communicate to physicians the possible negative results of herbal remedies use. Also, the interactions between herbal remedies and drugs of misuse should be communicated to consumers. en_ZA
dc.description.department Pharmacology en_ZA
dc.description.librarian am2017 en_ZA
dc.description.sponsorship The work was funded by In Vitro Drug Safety and Biotechnology. We are thankful for the financial contribution to Mahaffy -Gastroenterology Fund, Sunnybrook HSC, Toronto, ON, Canada. en_ZA
dc.description.uri en_ZA
dc.identifier.citation Neuman, M.G., Cohen, L.B. & Steenkamp, V. 2017, 'Pyrrolizidine alkaloids enhance alcohol-induced hepatocytotoxicity in vitro in normal human hepatocytes', European Review for Medical and Pharmacological Sciences, vol. 21, suppl. 1, pp. 53-68. en_ZA
dc.identifier.issn 1128-3602 (print)
dc.identifier.issn 2284-0729 (online)
dc.language.iso en en_ZA
dc.publisher Verduci Publishers en_ZA
dc.rights © 2017 European Review for Medical and Pharmacological Sciences en_ZA
dc.subject Alcohol-induced liver damage en_ZA
dc.subject Apoptosis en_ZA
dc.subject Caspase en_ZA
dc.subject CYP 2E1 en_ZA
dc.subject Glutathione en_ZA
dc.subject Herbal-induced hepatotoxicity en_ZA
dc.subject Normal human hepatocytes en_ZA
dc.subject Mitochondria en_ZA
dc.subject Pyrrilidozine alkaloids en_ZA
dc.subject Reactive oxygen species en_ZA
dc.subject Transmission electron microscopy en_ZA
dc.subject Veno-occlusive disease of the liver en_ZA
dc.title Pyrrolizidine alkaloids enhance alcohol-induced hepatocytotoxicity in vitro in normal human hepatocytes en_ZA
dc.type Article en_ZA

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