## 1 Introduction  
Diabetes mellitus (DM) is a disease that causes complex metabolic disorder associated with insulin resistance, impaired insulin signaling, \(\beta\)-cell dysfunction, abnormal glucose levels and changes in lipid metabolism [1]. The condition of high blood-glucose level (hyperglycemia) is caused by impaired of insulin production or secretion, insulin resistance. Hyperglycemia causes an increase of reactive oxygen species (ROS) levels which is not counterbalanced by an adequate supply of antioxidants. This imbalance can cause oxidative stress which is the source of the development of diabetes mellitus complications because it triggers the development of insulin resistance [2]. Complication of diabetes mellitus causes chronic wound healing disorders such as inflammation, tissue formation granulation, re-epithelialization and tissue renovation [3]. All these complications often result in open wounds with long-term healing problems that frequently cause the need of amputation. Epidemiological data report that 2.8% of the world's population suffered from diabetes in 2000, and the trend is expected to increase up to 4.4% by 2030 and also the percentage of amputation in diabetic wounds is expected to increase to about 50-70% [4]. The excessive generation of ROS in diabetic conditions is caused by acute serum glucose and the accumulation of advanced glycation end-products (AGEs). Endogenous or externally supplied antioxidants (due to inadequate supply of antioxidants) can lower ROS levels through the reduction of cellular molecular oxidation. Antioxidants obtained can neutralize the oxidative stress to improve wound healing in diabetes [5]. Wound-healing processes in diabetic mice have been usually treated performed in general through the administration of topical medications, topical or systemic antibiotics and vascular reconstruction. However, open wound healing has a weakness due to the use of chemical substances that cause long-term side effects in diabetics [6; 7]. Alginate is a natural polysaccharide produced from _Sargassum_ sp. (among others) containing \(\alpha\)-L-gluturonic acid (G) and \(\beta\)-D-mannuronic acid (M) residues [8]. Alginate--in form of hydrogels, foams, films, nanofibers, topical formulations or wafers--has been widely used as bioactive dressing for wound healing [9]. As other biocompatible materials, alginate can be loaded natural compound or drugs for improved wound-healing process like simvastatin [10], honey [11], _Aloe vera_[12], curcumin [13]. Alginate can maintain a moist condition in the wound area and acts as antibacterial and antioxidant agent, absorb wound exudate as a hemostatic agent [14; 15; 16]. Moreover, alginate with composition of gluuronic acid residue (G) higher than Mannuronic acid residue (M) produce a more rigid structure, thereby increasing the availability of alginate ions to make it easier to absorb exudate and proton donor in the free radical scavenging process (antioxidant), so it is easy to wound healing. Molecular weight of polysaccharides affects the ability of radical scavenging. Reduction in molecular weight below 12 kDa can affect the conformational chain or gluuronic acid content which has an impact on the availability of alginate ions in radical scavenging [17]. _Abelmoschus esculentus_ L. is known as oka plant that contains many flavonoids that play a major role acting as antioxidant agents against ROS to inhibit free radicals [18]. Hence, the oka fruit may be used as an alternative medicine for the reduction of blood glucose and cholesterol levels as antidiabetic and antihyperlipidemic properties [19; 20]. In addition, oka fruit extract can accelerate wound healing through the induction of the production of cytokine and growth factor productions [21]. In this study, we report the characterization of alginate from _Sargassum duplicatum_ ([PERSON]) to evaluate its characteristic on the wound-healing process. The novelty of this study lies in investigating antioxidant effect of alginate from _S.