Evaluation and Characterization of Antioxidant Activity of Selected Herbs and Spices


  • Temasek Polytechnic, School of Applied Science, Singapore


This study investigated the antioxidant activity of selected herbs and spices, their effects in reducing the level of Reactive Oxygen Species (ROS) as well as their influence on the enzymatic activity of Superoxide Dismutase (SOD). Oxygen Radical Absorbance Capacity (ORAC) value was measured to determine the free radical scavenging capacity of the plant extracts, while a fluorescent probe was used to evaluate the ROS scavenging ability. An SOD assay was used to find out if the plants' aqueous extracts can stimulate the production of the SOD. Plant extracts which were found to exhibit high antioxidant activity such as curry leaves, rooibos tea and fenugreek showed superior free radical scavenging ability in hyperglycaemia-induced oxidative stress cell-line model. Plant extracts which exhibit low antioxidant activity such as Indian malabar, red silk cotton, cowitch, holy fruit tree and bitter gourd showed insignificant free radical scavenging ability. In addition, increased SOD activity was found in curry leaves and rooibos tea. This implied that the plants can increase the enzymatic activity of the SOD enzyme in order to reduce free radical levels, except for fenugreek which appeared to depend solely on the extract's ROS scavenging properties. Plant extracts such as Indian malabar, cowitch, bitter gourd, red silk cotton and holy fruit tree were found to have increase SOD activity, which may be due to the cellular defence mechanism stimulating the synthesis of SOD which was destructed by the ROS present in the cells. Further evaluation and characterization of the plants' for scientific proof is required to establish these traditional medicinal plants as effective means of disease treatment.


Oxygen Radical Absorbance Capacity, Reactive Oxygen Species, Superoxide Dismutase.

Subject Discipline

Pharmacy and Pharmacology

Full Text:


  • There are currently no refbacks.