Synthetic therapeutic drugs for asthma, a chronic airway inflammation characterised by strong eosinophil, mast cell, and lymphocyte infiltration, mucus hyper-production, and airway hyper-responsiveness, exhibit numerous side effects. Alternatively, the high antioxidant potential of palm oil phytonutrients, including vitamin E (tocotrienol-rich fractions; TRF) and carotene, may be beneficial for alleviating asthma. Here, we determined the therapeutic efficacy of TRF, carotene, and dexamethasone in ovalbumin-challenged allergic asthma in Brown Norway rats. Asthmatic symptoms fully developed within 8 days after the second sensitization, and were preserved throughout the time course via intranasal ovalbumin re-challenge. Asthmatic rats were then orally administered 30 mg/kg body weight TRF or carotene. TRF-treated animals exhibited reduced inflammatory cells in bronchial alveolar lavage fluid. TRF- and carotene-treated rats exhibited notable white blood cell reduction comparable to that from dexamethasone. TRF- and carotene-treatment also downregulated pro-inflammatory markers (IL-β, IL-6, TNF-α), coincident with anti-inflammatory marker IL-4 and IL-13 upregulation. Treatment significantly reduced asthmatic rat plasma CRP and IgE, signifying improved systemic inflammation. Asthmatic lung histology displayed severe edema and inflammatory cell infiltration in the bronchial wall, whereas treated animals retained healthy, normal-appearing lungs. The phytonutrients tocotrienol and carotene thus exhibit potential benefits for consumption as nutritional adjuncts in asthmatic disease.
Asthma has affected more than 300 million people worldwide and is considered one of the most debilitating global public health problems based on a recent statistical report from the Global Initiative for Asthma. Inflammation of the airways leads to the various interrelated mechanisms of innate and adaptive immunity acting mutually with the epithelium of the respiratory organ. Fucoxanthin is an orange or brown pigment which is naturally found in various seaweeds. To the best of our knowledge, there are no scientific claims or evidence of the curative effects of fucoxanthin against asthma. Hence, this present research was designed to investigate the curative activity of fucoxanthin against ovalbumin-induced asthma in a mouse model. Fucoxanthin (50 mg/kg) showed significant (P < 0.001) antiasthma activity. It effectively decreased intracellular secretion of reactive oxygen species and increased antioxidant enzyme activity. Fucoxanthin also decreased inflammatory cytokine markers in bronchoalveolar lavage fluid. Because fucoxanthin showed effective antiasthma activity against ovalbumin-induced asthma in experimental animals, further research on this natural antioxidant could lead to development of a novel drug for the treatment of asthma in humans.