The Main Protease (Mpro) plays a pivotal role in the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is considered a highly conserved viral target. Disruption of the catalytic activity of Mpro produces a detrimental effect on the course of the infection, making this target one of the most attractive for the treatment of COVID-19. The current success of the SARS-CoV-2 Mpro inhibitor Nirmatrelvir, the first oral drug for the treatment of severe forms of COVID-19, has further focused the attention of researchers on this important viral target, making the search for new Mpro inhibitors a thriving and exciting field for the development of antiviral drugs active against SARS-CoV-2 and related coronaviruses.

Oxidative stress plays an essential role in the pathological processes that trigger various chronic liver diseases and contributes to the development of hepatocarcinogenesis. Antioxidants from natural sources trap free radicals by converting them into non-harmful products and minimize oxidative stress, playing a crucial function in the treatment of free radical-induced diseases. However, the activity of these antioxidants is limited due their poor bioavailability, which is why various nano-drug delivery systems have been developed to improve their stability, promote smooth release, and targeted delivery for liver cancer treatment. Specifically, this review aims to report recent scientific findings of novel nano-formulations containing natural antioxidant molecules targeted for the treatment of liver cancer.