Investigation of chemical composition and bioactivity potential of total extract of endemic marrubium rotundifolium boiss.

Marrubium L. (Lamiaceae) has 40 taxons in the world. It is represented by 21 taxons in Turkey, the better part of which are endemic. Different Marrubium species, known as "bozotu, bozkaşık, karaderma", are used traditionally as diuretic, carminative, expectorant in Anatolia. Antioxidant, cyctotoxic, analgesic and anti-inflammatory effects of various Marrubium sp. were reported previously. As a result of phytochemical studies on Marrubium species, diterpenes, flavonoids, volatile oils, phenylpropanoid esters and phenylethanoid glycosides were isolated as main phytochemical groups. Marrubium rotundifolium Boiss. is an endemic species and distributed in Aegea. In this study, in order to determine the chemical components of methanol, ethylacetate and hexane extracts obtained from the air part of the plant, chromatographic methodes such as TLC (thin layer chromatography), HPLC (high pressure liquid chromatography) and GC-MS (gas chromatography- mass spectrometry) were used and bioactivity of extracts were investigated. The tested substances could not be detected with the TLC and HPLC. Germacrene-D (24.80 %), β-caryophyllene (23.39 %) and caryophyllene oxide (16.69 %) were identified as major compounds in the analysis of volatile oil. Phenolic content was not observed in the n-hexane and ethylacetate extracts when the total phenolic content was determined by the Folin-Ciocalteu method when phenolic contents of 20,62 ± 1,6 GAE μg/mg were observed in the methanol extract. According to the results of the determination of total flavonoid content by aluminum chloride / potassium acetate method, flavonoid contents in methanol and ethylacetate extracts were 70,76 QE μg/mg and 142,58 QE μg/mg, respectively, whereas the highest flavonoid content was observed in n-hexane extract 168,63 QE μg/mg. In the OH.- , ABTS and DPPH radical scavenging activity studies, M. rotundifolium methanol extract showed higher IC50 values at lower doses (0.277 ± 0.024, 3.21 ± 0.081, 0.033 ± 0.001 mg/ml, respectively). MTT method was used to determine in vitro cytotoxicity of plant extracts and no significant results were found in extracts on 3 cancers (CaCo-2, SHSY5Y and PC-3) and 2 non-cancer cell lines (NIH-3T3, HK-2). Only ethylacetate extract (128 μg/ml) showed antimicrobial activity against Staphylococcus aureus in the study of antimicrobial activity by microdilution method. Methanol and hexane extracts (128 μg/ml each) showed antimicrobial activity against Bacillus subtilis, both ethylacetate and hexane extracts (128 μg/ml) showed the same antimicrobial activity against Enterococcus faecalis bacterial strain. M. rotundifolium extracts only showed activity against Gram (+) bacterial strains. In conclusion, this study is which examines phytochemical and bioactivity properties of M. rotundifolium plant. It has been observed that the plant has a weak antimicrobial and cytotoxic effect with potential for antioxidant effect. It has been seen that the chemical content of all extracts of the plant were very rich with the studies made by the TLC. Therefore, it is planned to carry out further fractionation and purification studies in order to identify the compounds in the plant.