Effects of oligo-fucoidan on the immune response, inflammatory status and pulmonary function in patients with asthma: a randomized, double-blind, placebo-controlled trial

Asthma is a common disease occurring worldwide. The clinical treatment of asthma is constantly revised and updated; however, it is associated with side effects. Our previous in vitro and ex vivo studies found that oligo-fucoidan can improve allergic immune responses and reduce airway inflammation. The purpose of this clinical trial was to investigate the effects of oligo-fucoidan on the immune status, inflammatory response, and pulmonary function of patients with asthma. Twenty asthmatic patients were randomly divided into two groups: (1) control group: receiving regular asthma treatment and supplementation with placebo; (2) fucoidan group: receiving regular asthma treatment and supplementation with oligo-fucoidan. Pulmonary function tests, the "Asthma Control Questionnaire" survey, biochemical data, inflammatory factors, and immune cell subtypes were detected. During treatment, the levels of WBC (p = 0.038) and creatinine (p = 0.012 and p = 0.008 at 12th and 24th weeks) were significantly decreased in the fucoidan group. Lung function (FEV(1)/FVC pr) significantly increased in the fucoidan group (p = 0.046). Regarding the proportion of immune cells, the level of IFN(+) and CD4(+)IFN(+)cells in the fucoidan group was significantly increased during the treatment period (P < 0.05), while the proportions of CD3(+)CD4(+) cells (p = 0.048) and CD3(+)CD8(+) cells (p = 0.009) in the fucoidan group were significantly decreased during the treatment period. Regarding cytokines, the level of interleukin-8 (IL-8) was also significantly reduced in the fucoidan group during the treatment period.