Anti-diarrhea and anti-oxidant properties of Magnolol

YL Pang^1,2†, XF Han^3†, MA Bamikole⁴, ZH Gong¹, SX Tang³, ZL Tan^3*, WJ Xiao¹, CS Zhou³, M Wang³ and YL Deng¹

¹National Research Center of Engineering & Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha 410128, Hunan, , ²Guilin Tea Science Research Institute of Guangxi, Guilin 541004,Guangxi, ³Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha 410125, Hunan ⁴Department of Animal Science, Faculty of Agriculture, University of Benin, PMB 1154, Benin City, Nigeria.

*For correspondence: Email: zltan@isa.ac.cn or xiaowenjungong@163.com  Tel: 86-731-84619702; Fax: 86-731-84612685

Received: 20 April 2012                                                                         Revised accepted: 25 November 2012

Tropical Journal of Pharmaceutical Research, February 2013; 12(1): 85-91

Purpose: To provide an experimental basis for the anti-diarrheal and anti-oxidant properties of the bark extract of Magnolia officinalis Rehd. et Wils., a Chinese traditional herb called magnolol.

Methods: The effects of magnolol on castor oil-induced diarrhea, small intestinal transit (SIT) in mice were investigated. Additionally, the antioxidant activity of magnolol was assessed in mice by the following parameters: glutathione (GSH), total antioxidant capacity (T-AOC), antioxidant enzyme activities and their gene expression level.

Results: Compared with diarrhea model control group, magnolol (25, 50, or 100 mg/kg body weight) showed significant (p < 0.05) inhibitory activity against castor oil-induced diarrhea in mice. Administration of magnolol (25, 50, and 100 mg/kg) also lowered neostigmine-induced SIT acceleration to 60.34 ± 5.17, 59.61 ± 7.66, and 54.12 ± 7.27 %, respectively, as against 70.1 ± 6.89 % for neostigmine control group. In vivo antioxidant assay results showed that mice treated with magnolol exhibited significantly (p < 0.001) higher activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities in blood, compared to control. Similarly, magnolol proups showed significantly higher CAT and SOD and T-AOC activities (p < 0.01) than control in liver tissues. The 100 mg/kg magnolol group had significantly higher liver GSH content than normal control group (1.01 vs. 0.79 mg/mg protein). At 25 and 50 mg/kg doses, magnolol significantly enhanced gene expression levels of CAT (p < 0.01) in liver.

Conclusion: Findings from this study indicate that magnolol possesses anti-diarrheal activity and is probably one of the main anti-diarrhea ingredients of Cortex Magnoliae Officinalis. Magnolol modulation of the activity and gene expression of antioxidant enzymes may therefore exert beneficial effects in anti-oxidant defense.

Keywords: Magnolol, Diarrhea, Small intestinal transit, Antioxidant enzyme, Gene expression.