Application of the elevated plus-maze test in mice for evaluation of the content of Honokiol in water extracts of magnolia

Abstract

In our previous study using an improved elevated plus‐maze in mice, the oriental herbal medicine Saiboku‐to prolonged the time spent in open arms, showing an anxiolytic effect, and the effect was mainly caused by honokiol derived from magnolia. This study was carried out to compare the anxiolytic potentials of honokiol and water extracts of three magnolia samples; two being Kara‐koboku (Magnolia officinalis) (KA: from Zhejiang‐sheng, China; honokiol 0.25% and magnolol 1.16%, and KB: from Sichuan‐sheng, China; honokiol 1.72% and magnolol 1.71%), and one being Wa‐koboku (Magnolia obovata) (WA: from Iwate‐ken, Japan; honokiol 0.32% and magnolol 0.81%). Seven daily treatments with 0.1–1 mg/kg honokiol, but not 0.2 and 1 mg/kg magnolol, revealed an anxiolytic effect with the peak potential at 0.2 mg/kg. The anxiolytic potentials of 40 and 80 mg/kg KA, which contained the highest amount of magnolol, were almost equivalent to those of 0.1 and 0.2 mg/kg honokiol, respectively. KB, at 11.6 mg/kg, and 62.5 mg/kg WA resulted in almost the same anxiolytic potential as that of 0.2 mg/kg honokiol. No significant change in the ambulatory activity was produced by any drug treatment. These results suggest that honokiol is the chemical responsible for the anxiolytic effect of the water extract of magnolia and that the other chemicals including magnolol in magnolia scarcely influence the effect of honokiol. It is also considered that the elevated plus‐maze test is applicable for evaluation of the content of honokiol in magnolia. Copyright © 1999 John Wiley & Sons, Ltd.

The Anxiolytic Effect of Two Oriental Herbal Drugs in Japan Attributed to Honokiol from Magnolia Bark

“…Seven daily treatments with honokiol prolonged the time spent by mice in the open arms in the plusmaze test without signi®cantly changing the ambulatory activity, thus showing an anxiolytic effect. These ®ndings support the previous studies Kuribara et al 1998Kuribara et al , 1999. In this study, we evaluated the anxiolytic potential of 10 samples of Hange-koboku-to and Saiboku-to, Kampo medicines prepared with various Japanese magnolia barks (Wa-koboku) or Chinese magnolia barks (Kara-koboku) from which honokiol was derived.…”

“…Since Kampo medicines are composed of speci®ed mixtures of extracts of dried plant materials, there is a possibility that the chemicals interact to modify the individual pharmacological effects. However, as previously reported in Saiboku-to and magnolia bark (Kuribara et al 1999), if honokiol is the chemical selectively responsible for the anxiolytic effect of Kampo medicines prescribed with magnolia bark, they show almost the equivalent anxiolytic potential when the doses are adjusted for honokiol content.…”

“…A behavioural study using an elevated plus-maze test in mice also revealed the anxiolytic effect of Hange-koboku-to and Saiboku-to (Kuribara & Maruyama 1996), and determined that honokiol derived from magnolia (Fujita et al 1973;Itokawa 1986) was responsible for the anxiolytic effect of Saiboku-to Maruyama & Kuribara 2000). Furthermore, our pilot study demonstrated that water extracts of three magnolia samples, two being Kara-koboku (Magnoliae of®-cinalis, KA) and the other being Wa-koboku (Magnoliae obovata, WA), showed almost the same anxiolytic potential when the doses were adjusted for honokiol content (Kuribara et al 1999).…”

“…Further studies are required to estimate the modi®cation by undetermined chemicals of the anxiolytic effect of honokiol. However, taken together, the results obtained from this and previous (Kuribara et al 1999) studies, it is expected that our improved procedure for elevated plus-maze test in mice (Kuribara & Maruyama 1996;Kuribara et al 1996) may be applicable for estimation of content of honokiol in magnolia bark as well as in magnolia-containing Kampo medicines, in addition to the assessment of their anxiolytic potential.…”

A Randomized Controlled Trial of Chinese Patent Medicine Xiao’er Biantong Granules in the Treatment of Functional Constipation in Children

“…In recent years, an increasing number of studies have shown that FC is related to brain function abnormality and mental disorders. Houpo, which contains magnolol, is also used to treat clinical depression and anxiety-related disorders for its anxiolytic effect [ 16 , 17 ] and thus may possibly treat FC. JueMingZi, which contains anthraquinones [ 18 ], could improve motor function in mice colon, reduce expression of AQP3 in colon mucosa, and have significant effects on the treatment of slow-transit constipation [ 19 ].…”