The Targeting of Autophagy and Endoplasmic Reticulum Stress Mechanisms by Honokiol Therapy

In recent decades, special attention has been paid to cell death mechanisms, with the exception of apoptosis. This could be due to the resistance of cells, particularly cancer cells, to apoptosis. Among novel pathways, autophagy and endoplasmic reticulum (ER) stress have attracted the attention of researchers. A large number of antitumor drugs have been developed based on their modulatory effects on autophagy and ER stress. On the other hand, ER stress could stimulate autophagy and apoptosis, which is indicative of the dual role of this pathway. Therefore, the monitoring of these pathways could contribute to the treatment of pathological conditions. Among the multiple synthetic and natural modulators of autophagy and ER stress, natural agents are used more extensively owing to their few side-effects, valuable biological activities, and cost-efficiency. Honokiol as a lignin extracted from the bark of magnolia tree. This compound has been reported to have antioxidant, anti-inflammatory, anti-diabetic, and antitumor effects. The present study aimed to first introduce honokiol, autophagy, and ER stress and assess the modulatory effects of honokiol on the autophagy and ER stress mechanisms so as to demonstrate the therapeutic efficacy of this natural compound.