Low morbidity and mortality rates of coronary heart disease (CHD) have been found in Crete. 1 Lionis C Koutis A Antonakis N Isacsson A Lindholm L Fioretos M Mortality rates in a cardiovascular ‘low risk’ population in rural Crete. Fam Pract. 1993; 10: 300-304 Crossref PubMed Scopus (5) Google Scholar Some of the reasons proposed are low serum cholesterol, high physical activity, and a diet low in saturated fat and high in monosaturated fat. Herbs may also have a preventive effect. We studied the antioxidant effect on extracts of ten herbs collected in Crete. Origanum dictamnus (wild and cultivated dittany), Matricaria recutita (chamomile), Satureja thymbra (savory), Coridothymus capitatus (thyme), Mentha pulegium (penny royal), Salvia pomifera (wild sage), Salvia fruticosa (Greek sage), Origanum majorana (marjoram), Mentha spicata (spearmint) were collected between May and June, 1996, from the area of Mixorruma when then were flowering. All are native to Crete apart from Origanum majorana which was collected from a pot kept by a villager. The plants were air dried. About 1 g of each herb was extracted in 100 mL of water at 100°C by shaking for 5 min. Extracts were filtered and freeze dried. The ability of extracts to inhibit lipid peroxidation was assayed in human bronchiole cells (A 549 from ATCC, Rockville, MD, USA). 2 Leanderson P Olsen-Faresjö Å Tagesson C Green tea polyphenols inhibit oxidant-induced DNA strand breakage in cultured lung cells. Free Rad Biol Med. 1997; 23: 235-242 Crossref PubMed Scopus (86) Google Scholar Cells were seeded into 24-well plates, 200 000/well in 500 μL in Dulbecco's modification of Eagle's medium supplemented with 10% fetal calf serum and penicillin 50 IU/mL, streptomycin 50 IU/mL, and 2 mmol/L L-glutamine (Flow Laboratories, Irvine, UK) and allowed to attach overnight in 5% CO2 at 37°C. Cells were pretreated for 2 h with herb extract (50 μL of a 10 mg/mL stock solution in 1 mL culture medium, made fresh daily), or 10 μmol/L alpha-ditocopherol at 37°C. After treatment the cells were washed with PBS and exposed to 10 μmol/L iron (III) chloride for 30 min at 37°C, or a low-dose of ozone for 1 min in a plastic container exposed to ozone from an ozoniser (Coralife model 100). Lipid peroxidation was determined by analysis of thiobarbituric-acid reactive substances. 200 μL 20% (w/v) trichloroacetic acid and 400 μL thiobarbituric acid (Merck, Darmstadt, Germany) was added to each well, the plate was covered and incubated at 95°C for 40 min and then chilled before determination of the absorbance at 543 nm. A standard curve of malondialdehyde was made from 1,1,3,3-tetraethoxypropane (Sigma Chemical Co, St Louis, MO, USA).