Safety evaluation of short-term exposure to chitooligomers from enzymic preparation

Qin, Caiqin; Gao, Junan; Wang, Liansheng; Zeng, Lintao; Liu, Yi

doi:10.1016/j.fct.2005.11.009

Cited by 60 publications

(40 citation statements)

References 29 publications

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“…The beneficial properties of COS have recently been recognized and exploited in the development of nutritional food (Qin et al 2006). The beneficial health effects of COS can be largely attributed to its antioxidant activity (Xu et al (GlcN) 3 ].…”

Section: Antioxidant Activitymentioning

confidence: 99%

Chitooligosaccharides antagonize the cytotoxic effect of glucosamine

Assis

Costa

Melo-Silveira

et al. 2011

World J Microbiol Biotechnol

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Chitooligosaccharides (COS) are partially hydrolyzed compounds derived from chitosan that exhibit a number of biological activities, including antitumor, antibacterial and antifungal properties. In this work, we examined the cytotoxicity of pure COS and oligomers A, B and C (solutions composed of different amounts of COS) produced by enzymatic hydrolysis using a crude enzyme extract produced by the fungus Metarhrizium anisopliae. The antiproliferative effect of these molecules was analyzed using tumor cell lines (HepG2 and HeLa cells) and in a normal cell line (3T3). The antioxidant activity was analyzed in several in vitro experiments. Glucosamine showed higher toxicity (approximately 92%) to all cell lines studied. However, the oligomers obtained after hydrolysis demonstrated no toxic effects on the normal cells (3T3). Furthermore, we showed that a small amount of other COS can decrease the cytotoxic effect of glucosamine against 3T3 cells, indicating that glucosamine could be used as an antitumor drug in the presence of other COS. In addition, different effects were found in antiproliferative assays, which depended on the COS composition in the oligomers (A, B and C), showing that a combination of them may be essential for developing antineoplastic drugs. Superoxide anion scavenging was the main antioxidant activity demonstrated by the COS and oligomers. This activity was also dependent on the oligomer composition of the chitosan hydrolysates. Further work will identify the ideal proportions of COS and glucosamine for maximizing the effects of these biological activities.

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Section: Antioxidant Activitymentioning

confidence: 99%

Chitooligosaccharides antagonize the cytotoxic effect of glucosamine

Assis

Costa

Melo-Silveira

et al. 2011

World J Microbiol Biotechnol

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“…Low molecular weight chitosans/chito-oligomers are of particular interest due to their biological activities such as anti-cancer 3 and in preventing progression of diabetes mellitus. 4 Low molecular weight chitosans were prepared using various chemical/enzymatic modifications in the recent past 5 .…”

Section: Introductionmentioning

confidence: 99%

Effect of Physicochemical Modifications on Antioxidant Activity of Water-soluble Chitosan

Weerakkody¹,

Labbett²,

Cheng³

et al. 2010

Food Biophysics

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Water-soluble chitosan was processed using ultrasonication, microfluidisation and homogenisation to modify its physicochemical properties. The effect of using sonicated chitosan on formation of chitosan-glucose conjugates was investigated. Untreated and sonicated chitosan conjugates were prepared under varying reaction conditions (such as ratios of reactants, pH and temperature). The conjugates formed were evaluated for colour development and antioxidant activity. For both untreated and sonicated chitosans, the reactivity was found to be higher at pH 6.0/121°C than at pH 4.9/121°C. The reactivity was found to be lower at 105°C at both pH conditions than at 121°C. This clearly demonstrated the greater reactivity at higher temperature irrespective of the reaction pH. Antioxidant activity studies indicated that the conjugates formed at 121°C had higher activity. Although sonication of water-soluble chitosan led to slightly enhanced viscosity indicating higher reactivity, it did not improve the antioxidant activity.

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“…No significant differences are reported in body weight, food consumption, food availability, hematology values, clinical chemistry values, or organ/body weight ratios. No abnormality of any organ was found during histopathological examination (Qin et al 2006).…”

Section: Regulations and Commercial Applicationsmentioning

confidence: 99%