In first part of this paper an overview is given about glucomannans sources, characterisation and use for healing of human diseases. In the second part an experimental study is presented. The study is focused on assessing the contribution of the in vivo antioxidant properties of Candida utillis cell-wall glucomannan (GM) on its anti-arthritic effect. For this purpose not only biochemical methods were used but also chemiluminiscence measurements were performed in whole blood and in selected tissues, as spleen and hind paw taken from arthritic rats treated with GM in two doses (7.5 mg/kg and of 15 mg/kg body weight) daily per os during 28 experimental days. Additionally, the functionality of neutrophils was evaluated by flow cytometry. An original approach was the determination of CoQ levels in mitochondria of skeletal muscles in AA treated by GM. The anti-arthritic effect of GM in adjuvant arthritis was evidenced using evaluation with clinical parameters – hind paw volume and body weight of experimental Lewis rats. GM in vivo antioxidant activity has a large impact on this effect, both in the whole system and locally. The local effect of GM was primarily exerted in the hind paw tissue and mitochondria of skeletal muscles. As to the intensity of GM effects observed for the tested doses of 7.5 and 15 mg/kg b.w., no significant difference was manifested; however the lower dose was more effective concerning the number of parameters affected. The results suggest that Candida utilis cell-wall GM is a potential immunomodulative agent in treating exaggerated neutrophilic inflammation accompanying arthritis and thus GM seems to be beneficial for rheumatoid arthritis therapy.