ANTIOXIDANT AND ANTIBACTERIAL ACTIVITIES OF VARIOUS EXTRACTS OF BORAGO OFFICINALIS FLOWERS

Antioxidant and antibacterial activities of various extract of Borage (Borago officinalis) flowers were evaluated. The antioxidant activity of the extracts was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), beta-carotene/linoleic acid and reducing power assays. In DPPH assay, the order of free radical scavenging activity of the extracts was: methanol extract (ME) > acetone extract (AE) > water extract (WE). In beta-carotene/linoleic acid assay, the inhibition capacity (%) of WE (95.62%) was in the highest level. When reducing power assay was used, a similar activity pattern was observed as given in the DPPH assay. The antibacterial activity of the extracts was tested by disk agar diffusion against four bacteria. The AE and WE of Borage flowers were effective against Bacillus subtilis and Listeria monocytogenes, respectively. In conclusion, the WE of Borage flower showed potent antioxidant activity. PRACTICAL APPLICATIONS In recent years, many researches have been carried out to find new sources of natural antioxidants. Natural antioxidants, derived from plants, can be used to preserve raw and processed foods. B. officinalis flowers are used as herbal tea and medicine in Iran. However, its antioxidant activity is still unknown. In this study, the WE of Borage exhibited potent antioxidant activity. Therefore, this extract has the potential to be used in food systems.