Oligochitosan Synthesized by Cunninghamella elegans, a Fungus from Caatinga (The Brazilian Savanna) Is a Better Antioxidant than Animal Chitosan

Abstract

Animal chitosan (Chit-A) is gaining more acceptance in daily activities. It is used in a range of products from food supplements for weight loss to even raw materials for producing nanoparticles and hydrogel drug carriers; however, it has low antioxidant activity. Fungal oligochitosan (OChit-F) was identified as a potential substitute for Chit-A. Cunninghamella elegans is a fungus found in the Brazilian savanna (Caatinga) that produces OligoChit-F, which is a relatively poorly studied compound. In this study, 4 kDa OChit-F with a 76% deacetylation degree was extracted from C. elegans. OChit-F showed antioxidant activity similar to that of Chit-A in only one in vitro test (copper chelation) but exhibited higher activity than that of Chit-A in three other tests (reducing power, hydroxyl radical scavenging, and iron chelation). These results indicate that OChit-F is a better antioxidant than Chit-A. In addition, Chit-A significantly increased the formation of calcium oxalate crystals in vitro, particularly those of the monohydrate (COM) type; however, OChit-F had no effect on this process in vitro. In summary, OChit-F had higher antioxidant activity than Chit-A and did not induce the formation of CaOx crystals. Thus, OChit-F can be used as a Chit-A substitute in applications affected by oxidative stress.

Antioxidant Baccharis trimera Leaf Extract Suppresses Lipid Accumulation in C. elegans Dependent on Transcription Factor NHR-49

“…The assays were performed as previously described [ 53 ] to analyze the in vitro antioxidant activity of BT, as well as the total antioxidant capacity (TAC), reducing power, iron chelation, copper chelation, superoxide radical scavenging and hydroxyl radical scavenging. The absorbance of the solution was measured using an Agilent Bio Teck Epoch microplate spectrophotometer (Agilent Technologies, Santa Clara, CA, USA).…”

“…In the case of BT, from 1.0 mg/mL, no further alterations in the absorbance values were identified. Therefore, this was the concentration chosen to calculate the total antioxidant capacity (TAC), as described earlier [ 53 ]. Ascorbic acid was used as standard.…”

“…The iron chelating ability of BT was evaluated as described earlier [ 53 ]. Briefly, BT (0.1, 0.5, 1.0 and 2.0 mg/mL) was added to the reaction mixture containing FeCl 2 (0.05 mL, 2 mM) and ferrozine (0.2 mL, 5 mM).…”