Anti-inflammatory phenolic glycosides from endemic Marrubium rotundifolium Boiss.

Marrubium rotundifolium Boiss. is an endemic plant distributed in Aegean Region of Türkiye. It's traditionally used in Anatolian medicine for treatment of cold and flu, dyspepsia, costiveness and intestinal spasms. However, phytochemical studies on the plant are limited. In the present study, five phenolic glycosides 4',5,6,7-tetramethoxy scutellarein (1), apigenin-7-O-(3"-O-E-p-coumaroyl)-ß-d-glucopyranoside (2), tiliroside (3), 4-(ß-d-glucopyranosyloxy) benzoic acid (4), and astragalin (5) were isolated from the aerial parts of M. rotundifolium and their structures were elucidated on the basis of spectroscopic methods (1D and 2D NMR, and MALDI-TOF/MS). Moreover, anti--inflammatory activities of the isolated compounds were evaluated by measurements of interleukins (IL-1ß, IL-6) and tumour necrosis factor-alpha (TNF-α) levels. Tiliroside exhibited the highest potency in all pathways. At concentrations of 3 and 6 µg/mL, it significantly decreased the levels of pro-inflammatory cytokines IL-1ß (192.53 and 175.54 pg/mL), IL-6 (925.52 and 946.81 pg/mL), and TNF- α (6465.86 and 6267.67 pg/mL). This is the first report on phenolic profile of endemic M. rotundifolium. The anti-inflammatory and antidiabetic activity potential of the plant should be investigated in further studies.

Chemical Profile and Cytotoxicity Evaluation of Aerial Parts of Marrubium vulgare L. From Different Locations in Turkey.

Marrubium vulgare L. (Lamiaceae) is used for respiratory and gastrointestinal system disorders in folk medicine. According to European Pharmacopoeia criteria, standardization of the plant is defined by its marrubiin content. In present study, phenolics, marrubiin and essential oil compositions of M. vulgare from different locations in Turkey were analyzed quantitatively by UPLC, GC and GC/MS. Besides, their cytotoxic potentials were evaluated. In the samples, forsythoside B (77-400 mg/100 g dw), arenarioside (forsythoside F) (0-241 mg/100 g dw), verbascoside (acteoside) (171-416 mg/100 g dw) and apigenin-7-O-glucoside (0-17 mg/100 g dw) were determined in different ranges. Marrubiin contents (0.58-1.46 %) of some samples were two times higher than European Pharmacopoeia standards (0.7 %). ß-Caryophyllene (7.24-20.34 %), (Z)-ß-farnesene (1.58-34.85 %), germacrene D (9.8-13.37 %), bicyclogermacrene (1.71-8.63 %) and ß-bisabolene (0-16.68 %) were detected as major compounds in essential oils. The sample from the west of Aegean Region showed cytotoxicity against human neuroblastoma (SH-SY5Y) cell lines (IC50 : 59.80 µg/mL) although it has no effect on non-cancerous NIH-3T3cell lines. This is the first report on phenolic profiles of M. vulgare populations from Turkey. Their potential as marrubiin source for pharmaceutical industry should be considered.