Pyrroloquinoline quinone attenuates isoproterenol hydrochloride-induced cardiac hypertrophy in AC16 cells by inhibiting the NF-κB signaling pathway

Pyrroloquinoline quinone (PQQ) is a naturally occurring redox co-factor that functions as an essential nutrient and antioxidant, and has been reported to exert potent anti-inflammatory effects. However, the therapeutic potential of PQQ for isoproterenol hydrochloride (Iso)-induced cardiac hypertrophy has not yet been explored, at least to the best of our knowledge. In the present study, the anti-inflammatory effects of PQQ were investigated in Iso-treated AC16 cells, a myocardial injury cellular model characterized by an increase in the apparent surface area of the cells and the activation of intracellular cardiac hypertrophy-associated proteins. The results revealed that pre-treatment with PQQ significantly inhibited the expression of cardiac hypertrophy marker proteins, such as atrial natriuretic peptide, brain natriuretic peptide and β-myosin heavy chain. PQQ also inhibited the activation of the nuclear factor (NF)-κB signaling pathway in Iso-treated AC16 cells, thus inhibiting the nuclear translocation of NF-κB and reducing the phosphorylation levels of p65. On the whole, the findings of this study suggest that PQQ may be a promising therapeutic agent for effectively reversing the progression of cardiac hypertrophy.