Ramazani_2022_Life.Sci__120728

Alpha-bisabolol (alpha-bisabolol), an unsaturated monocyclic sesquiterpene alcohol, is known as one of the "most-used herbal constituents" in the world. Various therapeutic and biological properties of alpha-bisabolol in preventing oxidative stress, inflammatory disorders, infections, neurodegenerative diseases, cancers, and metabolic disorders have been reported. In this review, we evaluated new findings regarding the molecular mechanisms of alpha-bisabolol published from 2010 until 2021 in PubMed, Science Direct, and Scopus. The antioxidant mechanism of alpha-bisabolol is mainly associated with the reduction of ROS/RNS, MDA, and GSH depletion, MPO activity, and augmentation of SOD and CAT. Additionally, upregulating the expression of bcl-2 and suppression of bax, P53, APAF-1, caspase-3, and caspase-9 activity indicates the anti-apoptotic effects of alpha- bisabolol. It possesses anti-inflammatory effects via reduction of TNF-alpha, IL-1beta, IL-6, iNOS, and COX-2 and suppresses the activation of ERK1/2, JNK, NF-kappaB, and p38. The antimicrobial effect is mediated by inhibiting the viability of infected cells and improves cognitive function via downregulation of bax, cleaved caspases-3 and 9 levels, beta-secretase, cholinesterase activities, and upregulation of bcl-2 levels. Finally, due to multiple biological activities, alpha-bisabolol is worthy to be subjected to clinical trials to achieve new insights into its beneficial effects on human health.