Inhibitory effects of Tiger Milk mushroom (Lignosus rhinocerus) extract on ovalbumin-induced airway inflammation in a rodent model of asthma
Johnathan Malagobadan1, Siti Aminah Muhammad2, Siew Hua Gan3, Johnson Stanslas4, Wan Ezumi Mohd-Fuad2, Faezahtul Arbaeyah Hussain5 and Asma-Abdullah Nurul*2
1Asia Metropolitan University, 81750 Johor Bahru,
2School of Health Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
3School of Pharmacy, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia.
4Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
5Department of Pathology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
Abstract
Lignosus rhinocerotis Cooke. (L. rhinocerotis) is a mushroom traditionally used in the treatment of asthma and several other diseases by the indigenous communities in Malaysia. To date, there is limited scientific data on its anti-asthmatic effects. Aim of the study: To evaluate the effects of L. rhinocerotis on airway hyperresponsiveness, inflammation and asthma genes expression in an asthma murine model. Materials and methods: L. rhinocerotis extract (LRE) was prepared by a hot water extraction using a soxhlet. Animal studies were performed using two in vivo models; 1) house dust mite (HDM)-induced mice for evaluationof airway hyperresponsiveness (AHR) and 2) ovalbumin-induced rat for evaluation of airway inflammation. AHR was performed using a whole-body plethysmograph while airway resistance (RI) was measured in response to increasing concentrations of methacholine. Airway inflammation in rats was evaluated by assessing 1) eosinophils, neutrophils and lymphocytes numbers in the bronchoalveolar lavage fluid (BALF) by a flow cytometry, 2) mucus producing goblet cell in the lungs tissue by Periodic acid-Schiff (PAS) staining and 3) asthma pathway related genes expression in the lungs by a quantitative polymerase chain array. Results: Treatment with LRE significantly inhibited AHR in HDM-induced mice. Histological findings revealed that LRE can ameliorate OVA-induced histological changes in rats by attenuating mucus hypersecretion and goblet cell hyperplasia in the lungs. Flow cytometric analysis of BALF indicated that LRE reduced the number of eosinophils and helper T lymphocytes while elevating the number of regulatory T lymphocytes in the BALF. Subsequent analyses on gene expression revealed regulation of several important genes involved in allergy asthma pathway following treatment with LRE. Conclusion: In this study, LRE alleviates airway hyperresponsiveness, airway inflammation and regulates asthma genes expression, thus suggesting its therapeutic potential as a new armamentarium against allergic asthma.
Keywords: Airway hyperresponsiveness, allergic asthma, inflammation, gene expression, Lignosus rhinocerotis
Topic: Drug Discoveries and Development