Comet assay in the determination of the genotoxoxicity and antigenotoxicity of medicinal plant compounds

The Comet assay is widely used for measuring and analysing DNA breakage in different cells, which can be applied to in vitro, ex vivo and in vivo systems. Comet assay has revealed the genotoxic and antigenotoxic effects of various compounds [1]. This technique has important advantages. The advantages are as follows; high sensitivity in detection of low levels of DNA damage; small number of cells per sample; low cost; easy application [2]. Phenolic compounds have usually been regarded as possible antioxidants, so they have been used in food industry and in the prevention of diseases resulting from oxidative stress [3, 4]. But on the other hand it is suggested that various phenolic antioxidants can display pro-oxidant properties at high doses [5]. In this study, some of the well-known phenolic and oxygen rich compounds rich in medicinal and edible plants are selected due to their antioxidant activity. The genotoxic and antigenotoxic properties of Galangin (0 – 100µM), limonene (0 – 10000µM), naringin (0 – 2000µM), puerarin (0 – 50µM), ursolic acid (0 – 100µM), sinapic acid (0 – 2000µM), thymol (0 – 2000µM), carvacrol (0 – 2000µM), tannic acid (0 – 100µM), epigallocatechin gallate (0 – 250µM) and lycopene (0 – 20µM) in human lymphocytes were investigated by using Comet assay. The technique worked very well and the results showed that the herbal compounds had no genotoxic effects in low concentrations (0 – 250µM). However, in higher doses (250 – 10000µM), they induced DNA damage in the lymphocytes. These compounds were then studied in the same concentrations as mentioned above together with the positive controls to see if they have a protective effect in genotoxicity. By using Comet Assay, these compounds showed antigenotoxic activity and inhibited the oxidative stress induced DNA damage in the studied concentrations. The results also confirmed that Comet assay is a promising tool in identifying the protective effects of the herbal extracts.

Keywords: Comet, plant phenolics, genotoxicity, antigenotoxicity.

References:

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