Effectiveness of Magnolol, a Lignan from Magnolia Bark, in Diabetes, Its Complications and Comorbidities—A Review

Diabetes mellitus is a chronic metabolic disease characterized by disturbances in carbohydrate, protein, and lipid metabolism, often accompanied by oxidative stress. Diabetes treatment is a complicated process in which, in addition to the standard pharmacological action, it is necessary to append a comprehensive approach. Introducing the aspect of non-pharmacological treatment of diabetes allows one to alleviate its many adverse complications. Therefore, it seems important to look for substances that, when included in the daily diet, can improve diabetic parameters. Magnolol, a polyphenolic compound found in magnolia bark, is known for its health-promoting activities and multidirectional beneficial effects on the body. Accordingly, the goal of this review is to systematize the available scientific literature on its beneficial effects on type 2 diabetes and its complications. Taking the above into consideration, the article collects data on the favorable effects of magnolol on parameters related to glycemia, lipid metabolism, or oxidative stress in the course of diabetes. After careful analysis of many scientific articles, it can be concluded that this lignan is a promising agent supporting the conventional therapies with antidiabetic drugs in order to manage diabetes and diabetes-related diseases.

Bioinspired Honokiol Analogs and Their Evaluation for Activity on the Norepinephrine Transporter

In traditional Asian medicinal systems, preparations of the root and stem bark of Magnolia species are widely used to treat anxiety and other nervous disturbances. The biphenyl-type neolignans honokiol and magnolol are the main constituents of Magnolia bark extracts. In the central nervous system, Magnolia bark preparations that contain honokiol are thought to primarily interact with γ-aminobutyric acid A (GABAA) receptors. However, stress responses inherently involve the noradrenergic system, which has not been investigated in the pharmacological mechanism of honokiol. We present here interactions of honokiol and other synthesized biphenyl-type neolignans and diphenylmethane analogs with the norepinephrine transporter (NET), which is responsible for the synaptic clearance of norepinephrine and the target of many anxiolytics. Of the synthesized compounds, 16 are new chemical entities, which are fully characterized. The 52 compounds tested show mild, non-potent interactions with NET (IC50 > 100 µM). It is thus likely that the observed anxiolytic effects of, e.g., Magnolia preparations, are not due to direct interaction with the noradrenergic system.