During www.selleckchem.com/products/Vandetanib.html oxidative stress the human body is not able to maintain a homeostasis between endogenous antioxidants and ROS, with subsequent oxidation induced damage to biomolecules. Damage incurred may present itself as apoptosis, lipid peroxidation, DNA deg radation, protein modification, inflammation and ultim ately cellular death, which may aggravate oxidative stress related disorders. Antioxidants are molecules that decrease the propaga tion and activity of free radicals through neutralization and quenching reactions. Endogenous antioxidants, in cluding enzymes and mol ecules, aim to maintain homeostasis and reduce the deleterious effects of oxidative stress. GSH is a non protein thiol present at high levels in healthy cells, while the oxidized form appears at Inhibitors,Modulators,Libraries insignificant concentrations.

High concentrations of ROS can result in the depletion of GSH. During such periods the need for exogenous antioxidants becomes apparent. Due to controversies surrounding the potential cytotoxicity and carcinogenicity of synthetic Inhibitors,Modulators,Libraries an tioxidants, novel antioxidant sources such as herbal rem edies are therefore actively being investigated. Plants are known to be rich Inhibitors,Modulators,Libraries antioxidant sources. Burkea africana Hook. F and Syzygium cordatum Hochst. Ex C. Krauss are two African plants that have been described in literature to contain high levels of polyphenols and antioxidants in their bark extracts. The former, otherwise commonly known as the wild seringa, is used to treat heavy menstruation, abdominal pain, inflam mation and pneumonia, while the latter, otherwise known as the waterberry, is used ethnomedicinally as an emetic, treatment of diarrhea, stomach aches and chest complaints.

The aim of the present study was therefore to inves tigate the polyphenolic content of the bark extracts of B. africana and S. cordatum, assess their antioxidant activity and or cytotoxicity, as well as their efficacy to protect against Inhibitors,Modulators,Libraries oxidative stress in an in vitro cellular model, with the hope of determining their suitability of use as supplementary antioxidants. Methods Plant material and extract preparation Plant material Bark of B. africana and S. cordatum were collected du ring Spring by Mr Lawrence Tshikhudo in Venda and Dr N Hahn in Machado, Inhibitors,Modulators,Libraries res pectively. The identity of the plants was confirmed by Dr Hahn and voucher specimens deposited at the Depart ment of Toxicology and the Soutpansbergensis Herbarium, Makado. Bark was cleaned, air dried and ground to a fine http://www.selleckchem.com/products/Axitinib.html powder. Preparation of crude extracts Bark powder was macerated in 500 ml distilled water or methanol, sonicated for 30 min and kept at 4?C for 24 h. The supernatant was stored, and the marc extracted for a second time following the same method. The respect ive extracts were combined and vacuum filtered.