Chlorogenic acid prevents acetaminophen-induced liver injury: the involvement of CYP450 metabolic enzymes and some antioxidant signals

Abstract

Chlorogenic acid (CGA), a polyphenolic compound, is abundant in fruits, dietary vegetables, and some medicinal herbs. This study investigated the prevention of CGA against acetaminophen (AP)-induced hepatotoxicity and its engaged mechanisms. CGA reversed the decreased cell viability induced by AP in L-02 cells in vitro. In addition, CGA reduced the AP-induced increased serum levels of alanine/aspartate aminotransferase (ALT/AST) in vivo. The effect of CGA on cytochrome P450 (CYP) enzymatic (CYP2E1, CYP1A2, and CYP3A4) activities showed that CGA caused very little inhibition on CYP2E1 and CYP1A2 enzymatic activities, but not CYP3A4. The measurement of liver malondialdehyde (MDA), reactive oxygen species (ROS), and glutathione (GSH) levels showed that CGA prevented AP-induced liver oxidative stress injury. Further, CGA increased the AP-induced decreased mRNA expression of peroxiredoxin (Prx) 1, 2, 3, 5, 6, epoxide hydrolase (Ephx) 2, and polymerase (RNA) II (DNA directed) polypeptide K (Polr2k), and nuclear factor erythroid-2-related factor 2 (Nrf2). In summary, CGA ameliorates the AP-induced liver injury probably by slightly inhibiting CYP2E1 and CYP1A2 enzymatic properties. In addition, cellular important antioxidant signals such as Prx1, 2, 3, 5, 6, Ephx2, Polr2k, and Nrf2 also contributed to the protection of CGA against AP-induced oxidative stress injury.

Keywords: Acetaminophen; CYP450; Chlorogenic acid; Oxidative stress injury.

Fig. 1

Effect of CGA on AP-induced hepatotoxicity in vitro and in vivo (a) Chemical structure of CGA. (b) L-02 cells were pre-incubated with CGA for 15 min, and followed by incubation with AP (10 mmol/L) for 48 h. Cell viability was determined by the MTT method. Data are expressed as mean±SEM (n=5). (c) Mice were pre-administrated with CGA (10 and 40 mg/kg) for 7 consecutive days, and a single dose of AP (300 mg/kg, i.g.) was given on the final day. Mice were sacrificed 4 h after AP treatment. Data are expressed as mean±SEM (n=6–8). The results show that CGA ameliorates AP-induced hepatotoxicity in vitro and in vivo. ^* P<0.05, ^*** P<0.001 compared with control; ^# P<0.05, ^## P<0.01, ^### P<0.001 compared with only AP treatment

Fig. 2

Effects of CGA on liver mRNA expression and enzymatic activities of CYP2E1, CYP1A2, and CYP3A4 (a) CGA (40 mg/kg) performed no inhibition on liver mRNA expression of CYP2E1, CYP1A2, or CYP3A11. Data are expressed as mean±SEM (n=6). (b–d) Inhibition of CGA on the enzymatic activities of CYP2E1 (b), CYP1A2 (c), and CYP3A4 (d). Data are expressed as mean±SEM (n=6). ^* P<0.05, ^** P<0.01, ^*** P<0.001 compared with solvent control

Fig. 3

Effect of CGA on AP-induced liver oxidative injury (a) Liver MDA amount; (b) Liver ROS level; (c) Liver GSH amount. Data are expressed as mean±SEM (n=7–8). The results show that CGA ameliorates AP-induced liver oxidative injury. ^** P<0.05, ^*** P<0.001 compared with control; ^# P<0.05, ^## P<0.01,^### P<0.001 compared with only AP treatment

Fig. 4

Effect of CGA on liver Prx1–6 mRNA expression Liver mRNA expressions of Prx1–3 (a) and Prx4–6 (b) were detected by real-time PCR. Data are expressed as mean±SEM (n=8). ^* P<0.05, ^** P<0.01 compared with control; ^# P<0.05, ^## P<0.01 compared with only AP treatment

Fig. 5

Effect of CGA on liver mRNA expression of some other oxidative stress genes Liver mRNA expressions of Ephx2, Polr2k, and Fmo5 (a), MT1 and MT2 (b), SOD1 and SOD2 (c) were detected by real-time PCR. Data are expressed as mean±SEM (n=6–8).^* P<0.05, ^** P<0.01 compared with control; ^# P<0.05 compared with only AP treatment

Fig. 6

Effect of CGA on liver Nrf2 mRNA expression Liver mRNA expression of Nrf2 was detected by real-time PCR. Data are expressed as mean±SEM (n=8). ^* P<0.05 compared with control; ^# P<0.05 compared with only AP treatment