Abstract B73: The association of caffeine, trigonelline, and chlorogenic acid, active components from coffee, enhances caffeine-induced cytotoxicity in hepatocellular carcinoma cells
Authors: Romualdo Guilherme Ribeiro , Silva Tereza Cristina Da , Cogliati Bruno , Barbisan Luis Fernando 
Published: May 2019

Background: A cup of traditional coffee is a complex mixture of biologically active components, including caffeine (CAF), trigonelline (TRI), chlorogenic acid (CGA), and many others (1). Daily coffee consumption reduces by ~40% the risk of fibrosis/cirrhosis and hepatocellular carcinoma (HCC) in humans while, in general, decaffeinated coffee consumption does not (2-4). However, it is not clear whether this beneficial effect is attributed to the CAF alone or its association with other coffee constituents.

Aim: This work evaluated the modifying effects of CAF alone or associated to CGA and/or TRI in human HCC and hepatic stellate cells (HSC).

Experimental Procedures: Human C3A (clonal derivative of HepG2 cells) and LX2 (HSC) cells were grown in Eagle's Minimum Essential Medium supplemented with 10% fetal bovine serum (FBS), 100 U/ml penicillin, and 100 μg/ml streptomycin in a humidified atmosphere of 5% CO2 at 37oC. C3A and LX2 cells were seeded in 96-well plates at a density of 7 x 104 and 1 x 105 cells/mL, respectively, and treated with CAF alone (20, 40, 80, or 160 μM) or combined to TRI (10, 20, 40, or 80 μM) and/or CGA (10, 20, 40, or 80 μM) for 24 and 48 h. To select the CAF concentration, we considered the human serum peak (~35 µM) after the ingestion of ~450 mg of CAF, corresponding to 2-3 cups of coffee, and the toxic limit established for plasma concentration in humans (~400 μM) (5,6). For CGA and TRI, abundant in coffee beverages, we considered the 1:2 proportion (CGA or TRI:CAF) found in traditional coffee (1). We evaluated the cell viability (MTT assay) of LX2 and the cytotoxicity (lactate dehydrogenase [LDH] assay) of C3A cells.

Results: All tested CAF concentrations significantly increased cytotoxicity in C3A cells at 48 h compared to untreated cells (p&lt;0.001). The CAF+TRI+CGA combinations (20, 10, and 10 µM and 40, 20, and 20 µM, respectively) enhanced cytotoxicity at 24 and 48 h when compared to the control, CAF alone, and other associations (p&lt;0.001). Notably, these combinations enhanced caffeine-induced cytotoxicity at 48 h (p&lt;0.001). All treatments did not alter the viability of LX2 cells at both 24 and 48 h.

Conclusion: In general, the combination of CAF with other common compounds found in filtered and espresso coffee, TRI and CGA, enhanced CAF-mediated cytotoxicity on HCC cells at physiologically applicable concentrations. These findings suggest a synergistic effect of coffee compounds in exerting a chemopreventive effect and reducing the risk for HCC. The potential mechanisms related to these modifying effects will be further evaluated.

Financial support: CNPq (140251/2016-2) and FAPESP (16/14420-0).

References

1. Furtado KS, Polletini J, Dias MC, Rodrigues M a. M, Barbisan LF. Prevention of rat liver fibrosis and carcinogenesis by coffee and caffeine. Food Chem Toxicol 2014;64:20–6.

2. Bamia C, Lagiou P, Jenab M, et al. Coffee, tea and decaffeinated coffee in relation to hepatocellular carcinoma in a European population: Multicentre, prospective cohort study. Int J Cancer 2015;136(8):1899–908.

3. Liu F, Wang X, Wu G, et al. Coffee consumption decreases risks for hepatic fibrosis and cirrhosis: A meta-analysis. PLoS One 2015;10(11):e0142457.

4. Modi A, Feld J, Park Y, et al. Increased caffeine consumption is associated with reduced hepatic fibrosis. Hepatology 2010;51(1):201–9.

5. Skinner TL, Jenkins DG, Leveritt MD, et al. Factors influencing serum caffeine concentrations following caffeine ingestion. J Sci Med Sport 2014;17:516–20.

6. Nomura M, Ichimatsu D, Moritani S, et al. Inhibition of epidermal growth factor-induced cell transformation and Akt activation by caffeine. Mol Carcinogenesis 2005;44:67–76.

Citation Format: Guilherme Ribeiro Romualdo, Tereza Cristina Da Silva, Bruno Cogliati, Luis Fernando Barbisan. The association of caffeine, trigonelline, and chlorogenic acid, active components from coffee, enhances caffeine-induced cytotoxicity in hepatocellular carcinoma cells [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr B73.