Chemical And Bioactive Studies On Dracocephalum Heterophyllum Of The Genus Dracocephalum

Systematical study on the chemical constituents of traditional Chinese herbs is one of important routes to discover bioactive compounds. There are about 60 species belong to the genus Dracocephalum, family Labiatae. These plants distribute in alpine and semidry regions mainly in temperate Asia, with a few in Europe, one in North America. There are about 32 species,7 variations in China. Several species belong to the genus Dracocephalum are used as folk medicine for the treatment of tracheitis and cardiovascular disease in Xinjiang antonomous region. In our research, chemical constituents of Dracocephalum heterophyllum Benth were studied systematically. Thirteen compounds from the genus Dracocephalum, family Labiatae were selected in our research to test their antioxidant effect by DPPH and ABTS scavenging test. Among these compounds, eriodictyol-7-O-glucoside and Luteolin were screened the Nrf2 inducing activity using a stable cell line which could express luciferase. Futhermore, effects of luteolin on cisplatin-induced cytotoxicity in A549 cells were tested.Dracocephalum heterophyllum B., is one species of genus Dracocephalum, family Labiatae. It is traditionally used herb by Xinjiang and Tibet in China. It is a kind of perennial herb and distribute widely in Shanxi, Neimeng, Ningxia, Gansu, northwest of Sichuan, Xinjiang and Tibet in China. It mainly grows in the mountainous steppe and stony semi-desert dry regions, such as in the east elevation of 1100-2800 of Qinghai and Gansu, up to 5000 meters altitude from western part and 2200-3100 meters in Xinjiang.The aerial parts of this herb were systematically studied in our research, and nineteen compounds were obtained from the ethanol extract of this plant. Based on spectroscopy methods, all the compounds were elucidated as:ursolic acid (1), oleanolic acid (2), betulinic acid (3), betulin (4),2a-dihydroxy ursolic acid (5), diosmetin (6), luteolin (7), luteolin-5-O-β-D-glucoside (8), luteolin-7-O-rutinoside (9), apigenin-7-O-rutinoside (10), rosmarinic acid (11), methylrosmarinate (12), ethylrosmarinate (13),β-sitosterol (14), daucosterol (15), cholesterol glucoside (16), 3-methoxy-4-hydroxy-benzoic acid (17), o-hydroxybenzoic acid (18), Drahebenine (19), Drahebephin A (20), Drahebephin B (21). Among these compounds, Drahebenine, Drahebephin A and Drahebephin B were novel alkaloids. Compounds 10,16,19,20 and 21 were isolated from the genus of Dracocepahlum for the first time; 5,6,9,13,17 and 18 were isolated from this species for the first time.Thirteen compounds from four species of genus Dracocephalum, including Dracocephalum moldavica L., Dracocephalum rupestre H., Dracocephalum tanguticum M. and Dracocephalum heterophyllum B, were selected in our research to test their antioxidant effects. These compounds were screened for free radical scavenging activity by using DPPH and ABTS radical colorimetric assay. Results indicated that flavonoids and phenylpropanoids showed strong antioxidant activity. As a transcription factor, Nrf2 regulated the expression of phaseⅡand cellular detoxification enzymes, which could protect cells from radical and external toxic. Studies had indicated that induction of Nrf2 expression was helpful for the treatment of a lot of chronic diseases such as cardiovascular disease and diabetes. Eriodictyol-7-O-glucoside and luteolin from genus Dracocephalum were screened for the Nrf2 inducing activity using a stable cell line which could express luciferase. Results indicated that both eriodictyol-7-O-glucoside and luteolin could induce the expression of luciferase and might be potential Nrf2 activitors. Furthermore, luteolin could enhance the chemosensitivity of cisplatin.