Safety and Toxicology of Magnolol and Honokiol

Abstract

and bark extracts have been used for thousands of years in Chinese and Japanese traditional medicines and are still widely employed as herbal preparations for their sedative, antioxidant, anti-inflammatory, antibiotic, and antispastic effects. Neolignans, particularly magnolol and honokiol, are the main substances responsible for the beneficial properties of the magnolia bark extract (MBE). The content of magnolol and honokiol in MBE depends on different factors, including the plant species, the area of origin, the part of the plant employed, and the method used to prepare the extract. The biological and pharmacological activities of magnolol and honokiol have been extensively investigated. Here we review the safety and toxicological properties of magnolol and honokiol as pure substances or as components of concentrated MBE, including the potential side-effects in humans after oral intake. and genotoxicity studies indicated that concentrated MBE has no mutagenic and genotoxic potential, while a subchronic study performed according to OECD (Organisation for Economic Co-operation and Development) guidelines established a no adverse effect level for concentrated MBE > 240 mg/kg b.w/d. Similar to other dietary polyphenols, magnolol and honokiol are subject to glucuronidation, and despite a relatively quick clearance, an interaction with pharmaceutical active principles or other herbal constituents cannot be excluded. However, intervention trials employing concentrated MBE for up to 1 y did not report adverse effects. In conclusion, over the recent years different food safety authorities evaluated magnolol and honokiol and considered them safe.

Transcriptomic Insights into the Antifungal Effects of Magnolol on the Growth and Mycotoxin Production of Alternaria alternata

“…The potential mechanisms were to be investigated by comparative transcriptomic profiling between the control and magnolol-stressed A. alternata . Given that magnolol was considered safe by various food safety authorities over the past years [ 11 ], it would be a promising alternative for preservatives for the control of Alternaria pathogens and their mycotoxins.…”

Preparation of honokiol nanoparticles by liquid antisolvent precipitation technique, characterization, pharmacokinetics, and evaluation of inhibitory effect on HepG2 cells

“…It had been reported that the no-observed-adverse-effect-level for concentrated MBE (containing about 7.5% of honokiol) was 240 mg/kg body weight per day as an oral dose. 26 Considering the content of honokiol in concentrated MBE, the oral dose of honokiol was about 18 mg/kg. However, the dosage of honokiol nanoparticles (100 mg/kg) in the present study was far higher than 18 mg/kg.…”

Magnolol Ameliorates Behavioral Impairments and Neuropathology in a Transgenic Mouse Model of Alzheimer’s Disease

“…Therefore, therapeutic strategies for thwarting AD progression clearly remain an unmet medical need. Magnolol (MN) (the chemical structure is shown in Figure 1) is the essential natural neolignan and the main active ingredient responsible for the therapeutic properties of the bark of Magnolia officinalis, a herb widely used in Chinese medicine to treat inflammatory diseases with low toxicity [13]. The content of MN in the bark of M. officinalis is about 1.0-1.25% [13].…”