Free radical scavenging activity and the content of phenolic compounds in mints and balms cultivated in South-West Slovakia

Oxidative stress is an instigator of cell death and causes numerous human diseases. The effort of current medicine tries to eliminate oxidative stress by applying antioxidants in the therapy as well as in the prevention. Lamiaceae plants are important sources of natural antioxidants. The free radical scavenging activity of 50%-hydroalcoholic extracts of leaves of three Mentha L. species (M.×piperita L., M. spicata L., M. longifolia (L.) Huds. subsp. lavanduliodora) and two Melissa officinalis L. subspecies (M. officinalis L. subsp. officinalis cv. 'Citra', M. officinalis L. subsp. altissima Sibth. & Sm.), harvested in July and September, in the DPPH (2,2-diphenyl-1-picrylhydrazyl) test was determined. The content of total hydroxycinnamoic derivates [THD] [1], rosmarinic acid [RA] (by HPLC) and flavonoids [1] was determined as well. Hydroalcoholic extracts exhibited significant antioxidative activity (AA). AA was correlated with the content of the respective phenolic compounds.

	THD [%]		RA [%]		flavonoids [%]		AA SC50 [µg/ml]
	VII	IX	VII	IX	VII	IX	VII	IX
Mentha L.
M. x piperita	9.3	8.6	1.77	1.91	0.88	0.84	3.1	4.2
M. spicata	7.3	6.2	1.95	2.88	0.42	0.40	4.9	5.3
M. longifolia	4.0	1.8	1.19	0.80	0.53	0.51	5.8	9.8
Melissa officinalis L.
M. off. subsp. officinalis cv. 'Citra'	13.1	10.2	3.79	4.56	0.46	0.47	2.6	3.8
M. off. subsp. altissima	13.1	11.5	4.75	4.68	0.29	0.31	2.4	2.8

Acknowledgements: VEGA grant 1/4289/07 and VEGA grant 2/5052/25

Reference: 1. European Pharmacopoeia. 5^th edition (PhEur 5), Strasbourg: Council of Europe (2004) S1496–97, S1989–90