Investigation of photoprotective effects of polysaccharide-rich extracts of Cordyceps (Cs-HK1) against UVA radiation-induced DNA damage in human skin cells

Pao Yue-kong Library Electronic Theses Database

Investigation of photoprotective effects of polysaccharide-rich extracts of Cordyceps (Cs-HK1) against UVA radiation-induced DNA damage in human skin cells

 

Author: Poon, Pik-chi
Title: Investigation of photoprotective effects of polysaccharide-rich extracts of Cordyceps (Cs-HK1) against UVA radiation-induced DNA damage in human skin cells
Degree: M.Sc.
Year: 2009
Subject: Hong Kong Polytechnic University -- Dissertations.
Cordyceps.
Skin.
DNA -- Analysis.
Department: Dept. of Health Technology and Informatics
Pages: viii, 73 leaves : col. ill. ; 30 cm.
Language: English
InnoPac Record: http://library.polyu.edu.hk/record=b2322858
URI: http://theses.lib.polyu.edu.hk/handle/200/4908
Abstract: UVA radiation in sunlight is a significant photodamaging agent. The long wavelength of UVA (315-400nm) can penetrate skin deeply and generate free radicals, causing photoaging and DNA damage which may lead to skin cancers. Antioxidants in the skin may help prevent or lower UV-induced DNA damage. Polysaccharides in Cordyceps sinensis, a natural traditional Chinese medicine, were found to show free radical scavenging activities and trigger apoptosis in tumour cells. Cs-HKl is Cordyceps mycelial cultivate successfully fermented by researchers at The Hong Kong Polytechnic University. Cs-HKl is rich in polysaccharides. In this study, the effectiveness of photoprotective effect of Cs-HKl against UVA-induced DNA damage in human BJ fibroblasts was investigated using the comet assay. BJ cells were pre-incubated in four dosages (0, 50, 100 and 200 mg/L) of hot water extracts (HWE) or exopolysaccharide extracts (EPS) of Cs-HKl for 30 min and 24 hr before UVA irradiation. UVA-induced DNA lesions were revealed by T4EV treatment. Comet tail DNA % was scored as a measure of DNA damage and compared with control cells. Neither extracts showed direct UVA absorption effect. No significant (p > 0.05) improvement in UVA-induced T4EV specific DNA damage was recorded in cells pre-incubated in either extract. The photoprotective effect of Cs-HKl against UVA-induced DNA damage recognized by T4EV was not able to be demonstrated in the study.

Files in this item

Files Size Format
b23228581.pdf 5.512Mb PDF
Copyright Undertaking
As a bona fide Library user, I declare that:
  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

     

Quick Search

Browse

More Information