Seasonal variation of flavonoids in Teucrium polium L. (Lamiaceae)

Тhe aim of the present study was identification of flavone aglycones and determination of the content of each and the content of total flavonoids as well as investigation of the eventual seasonal variations of flavonoids in Teucrium polium L. (Lamiaceae). The plant samples were collected at six different locations in Republic of Macedonia, during summer in 1999, 2000 and 2003. For determination of seasonal variations, the samples were collected in v. Koleshino, in 2004, each month during the whole season. Six flavone aglycones (luteolin, apigenin, diosmetin, cirsiliol, cirsimaritin and cirsilineol) were identified in the hydrolyzed extracts of the over ground part of Teucrium polium by HPLC method. The most abundant flavone was luteolin, followed by apigenin and cirsimaritin. Great seasonal variations were found in the content of each and in the content of total amount of flavonoids. The most abundant flavone during the whole season was luteolin with the highest content in May. The content of total flavonids was the highest in the period from May to July, which could be recommended as the most convenience period in the season for collecting of the plant material from Teucrium polium. Key wоrds: Teucrium polium, flavonoids, HPLC analysis, seasonal variation * [email protected] Introduction Teucrium polium L. (Lamiaceae) is a sub-shrub plant native to the Mediterranean region and the Middle East. In Republic of Macedonia it is widely distributed and traditionally used by native inhabitants, as herbal hypoglycemic tea. The decoctum of T. polium is used as an appetizer especially in children and also as a spice. Some biological and therapeutic effects have been reported for the plant such as antioxidant (Esmaeili et al., 2009; Ardestani et al., 2008), antiinflammatory (Tariq et al., 1989; Capasso et al., 1983), antinociceptive (Baluchnejadmojarad et al., 2005; Abdollahi et al., 2003), antipyretic (Aggelis et al., 1998; Autore et al., 1984), anti-microbial (Autore et al., 1984), hypolipidemic (Rasekh et al., 2001), hepatoprotective (Panovska et al., 2007), cytotoxic and apoptotic effects (Rajabalian et al., 2008). The plant poses complex chemical composition with presence of new clerodane type diterpenes (Malakov and Papanov, 1983; Marquez and Valverde, 1979), essential oil with dominating sesquiterpene alcohols and pinenes (Cozzani et al., 2005; Moghtader, 2009; Kabouche et al., 2007), phenylethanoid glycosides such as verbascoside and poliumoside (Oganesyan et al.,1991), flavone glycosides with highly methylated aglycons (Verykokidou-Vitsaropoulou and Vajias, 1986; Rizk et al., 1986; Kawashty et al., 1999; Harborne et al., 1986; Sharififar et al., 2009), etc. Flavonoids are representing the most important group of active components of Teucrium species, and many of the activities of these plants are attributed to the flavonoid