The use of a microwave-assisted solvent extraction coupled with HPLC-UV/PAD to assess the quality of Marrubium vulgare L. (white horehound) herbal raw material.

INTRODUCTION: Marrubium vulgare is a herbal remedy presents in several European Pharmacopoeias and commonly marketed as white horehound. The chemotaxonomic marker of Marrubium genus is marrubiin and its content may change in response to biotic and abiotic stress. OBJECTIVE: Development of a microwave-assisted solvent extraction (MASE) methodology suitable for exhaustively extracting marrubiin from M. vulgare leaves, easily applicable to large sets of samples. Evaluation of the influence of copper(II) on marrubiin production. MATERIAL AND METHODS: M. vulgare leaves were dried, extracted exploiting MASE and analysed via high-performance liquid chromatography ultraviolet photodiode array detection (HPLC-UV/PAD) system. A design of experiments approach was adopted to select the best extraction conditions. Extraction parameters (solvent composition, extraction time and temperature), were studied applying two full factorial experimental designs in a sequential approach. To analyse samples, a rapid HPLC-UV/PAD method was set up. RESULTS: The best results in terms of marrubiin extraction yield were obtained extracting samples at 120°C with 100% ethanol, for 15 min (3 × 5 min microwave cycles). The developed methodology was successfully applied to matrices grown in Greenhouse conditions and under stress induced by copper(II), selected as model agent for abiotic stress. Progressively decreasing production of marrubiin was evidenced in connection with treatment with 80, 200 and 300 mg/L copper sulphate. CONCLUSION: An efficient methodology for the extraction and determination of the amount of marrubiin in large sets of samples of M. vulgare plants was developed. Results demonstrated that marrubiin is an easily detectable marker useful for evaluating M. vulgare reaction to stress.

Marrubium vulgare L. Leave Extract: Phytochemical Composition, Antioxidant and Wound Healing Properties.

Several factors contribute in wound generation, e.g., accidental traumas or surgery, and in certain cases, this dermal injury may have a devastating outcome. When skin damage occurs, the human body puts in place a sophisticated choreography, which involves numerous repairing processes to restore physiological conditions. Nevertheless, natural healing mechanisms are ineffective towards chronic or non-healing wounds and thus, therapeutic strategies may represent the only beneficial alternative to counteract these tissue insults. Over the years, numerous studies showed the great potential of plants in promoting wound healing, by virtue of their high contents in antioxidant species. These compounds trigger a molecular cascade that collimate into the promotion of reparative processes. In this article, we report on the potential effect on wound healing of Marrubium vulgare L., a medicinal plant well known for several pharmaceutical activities. To this aim, the methanolic extract was prepared and subjected to a phytochemical investigation, quantifying the amount of marrubiin via NMR and drawing the phytochemical fingerprint via high performance liquid chromatography-ultra violet/photodiode-array detection-electrospray/mass (HPLC-UV/PAD-ESI/MS) analysis. Lastly, the antioxidant properties and wound healing potential have been evaluated.