Determination of Α- and Β-Thujone in Wormwood and Sage Infusions of Greek Flora and Estimation of their Average Toxicity

Introduction

Artemisia absinthium L., commonly known as wormwood, is a yellow-flowering perennial plant that growing in various parts of Europe and Siberia, and it is used for its antiparasitic and digestive properties for the treatments of anorexia and indigestion. The aerial parts of the plant are used in many herbal preparations, dietary supplements, and alcoholic beverages (e.g. absinthe)¹. Wormwood infusions are being used as a medicinal remedy, due to the wide range of its therapeutic activities².

Salvia sp. (sage) is an aromatic small perennial shrub native to the Mediterranean region. Sage is cultivated for culinary and medicinal purposes and it is mainly used as infusion. Also, it has been used as a preservative or flavoring agent in food products and as an aromatic agent in perfumes and cosmetics³. The significant amount of terpenoids contained in sage teas, are contributing to their antioxidant, hepatotoxic, antimutagenic and antidiabetic effects⁴.

Thujone is a natural monoterpene ketone present in variable amounts in a large number of plants⁵, such as sage (Salvia officinalis), clary (Salvia sclarea), tansy (Tanacetum vulgare), wormwood (Artemisia artemisia) and white cedar (Thuja occidentalis L.). As so, it is included as a significant component in many dietary botanical supplements and herbal medicinal products⁶. Thujone occurs naturally in two diastereomeric forms: (-)-α-thujone and (+)-β-thujone (Figure 1). Concerning health effects parent compound is potentially toxic therefore, the presence of α- or β-thujone in food and beverages has been regulated by law in several countries⁷. Additionally, clinical tests to experimental animals has proved that α-thujone was more toxic than β-thujone or a mixture of isomers⁸.

The compound thujone is the psychotropic component of absinthe, wormwood oil and some other herbal medicines⁹, as sage⁴. α-Thujone reduces activity of 5-ΗΤ3 receptor which explains the psychotropic action⁹. Thujone (α- and β-) has neurotoxic action⁵, causing tonic-clonic convulsions due to inhibitory action on the GABAA receptor¹⁰. Finally, both isomers have shown hepatotoxicity¹¹ and porphyrogenic activity¹² .

The restrictions applied to thujone levels in food products...