Hepato- and reno-protective effects of thymoquinone, crocin, and carvacrol: A comprehensive review

Medicinal plants are rich in nutrients and phytochemicals which prevent and treat a wide range of ailments. Accumulating experimental studies exhibit that some bioactive ingredients extracted from medicinal plants have suitable therapeutic effects on hepatic and renal injuries. This review focuses on the hepato- and reno-protective effects of thymoquinone, crocin, and carvacrol. The relevant literature was retrieved from PubMed, Scopus, Web of Science, and Google Scholar databases from the beginning of 2015 until the end of November 2021. According to the scientific evidence, the considered phytochemicals in this review have been applied with useful therapeutic effects on hepatic and renal damage. These therapeutic effects were mainly mediated through the amelioration of oxidative stress, suppression of inflammatory responses, and inhibition of apoptosis. Intracellular signaling pathways linked to nuclear factor kappa B (NF-κB), adenosine monophosphate-activated protein kinase, c-jun N-terminal kinase, and extracellular signal-regulated kinase 1/2 and Toll-like receptors are the most important pathways targeted by these phytochemicals. Up-regulation of transcription factor Nrf2 and down-regulation of transforming growth factor-beta 1 by these natural compounds also contribute to the alleviation of hepatic and renal injuries.