Abstract:The present study aimed to evaluate acetylcholinesterase (AChE) inhibitory and antioxidant activities of Lamiaceae medicinal plants growing wild in Croatia. Using Ellman's colorimetric assay all tested ethanolic extracts and their hydroxycinnamic acid constituents demonstrated in vitro AChE inhibitory properties in a dose dependent manner. The extracts of Mentha x piperita, M. longifolia, Salvia officinalis, Satureja montana, Teucrium arduini, T. chamaedrys, T. montanum, T. polium and Thymus vulgaris at 1 mg/mL showed strong inhibitory activity against AChE. The antioxidant potential of the investigated Lamiaceae species was assessed by DPPH • scavenging activity and total antioxidant capacity assays, in comparison with hydroxycinnamic acids and trolox. The extracts differed greatly in their total hydroxycinnamic derivatives content, determined spectrophotometrically. Rosmarinic acid was found to be the predominant constituent in most of the investigated medicinal plants (by RP-HPLC) and had a substantial influence on their AChE inhibitory and antioxidant properties, with the exception of Teucrium species. These findings indicate that Lamiaceae species are a rich source of various natural AChE OPEN ACCESSMolecules 2014, 19 768 inhibitors and antioxidants that could be useful in the prevention and treatment of Alzheimer's and other related diseases.

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The aim of this study was the evaluation of the antioxidant capacity of Cotoneaster melanocarpus Lodd. and the identification of antioxidant active constituents of this plant. C. melanocarpus Lodd. is a shrub indigenous to Mongolia and used in Traditional Mongolian Medicine as a styptic. Before extraction, the plant material was separated into three parts: young sterile shoots, older stems and leaves. All these parts were extracted with water, methanol, ethyl acetate, dichloromethane and hexane, successively. The methanolic extract of the sterile shoots showed the highest antioxidant activity in the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay (IC50 30.91 ± 2.97 µg/mL). This active extract was further analyzed with chromatographic methods. TLC fingerprinting and HPLC indicated the presence of the flavonol glycosides quercetin-3-O-rutinoside (rutin), quercetin-3-O-galactoside (hyperoside) and quercetin-3-O-glucoside (isoquercetin), ursolic acid as well as chlorogenic acid, neochlorogenic acid and cryptochlorogenic acid. The findings were substantiated with LC-MS. All identified compounds have antioxidant properties and therefore contribute to the radical scavenging activity of the whole plant.

Curcuma wenyujin is a traditional medicinal plant in China. The non-steamed rhizomes, steamed rhizomes and steamed roots of this plant are used as herbal medicines in three clinics, namely Pian-jiang-huang (PJH), Wen-e-zhu (WEZ), and Wen-yu-jin (WYJ), and are officially listed in the Chinese Pharmacopoeia. The purpose of this study was to conduct a comparative analysis of the three essential oils extracted from the C. wenyujin rhizomes and roots using GC-MS, and in doing so thirty compounds were identified. Principal component analysis (PCA) effectively distinguished the samples taken from the three different groups. Monoterpenoids, including camphene, linalool, camphor, isoborneol, borneol and eucalyptol, were characteristic components of the PJH oil, while β-elemene, β-elemenone, γ-elemene and δ-elemene were typical components of the WEZ oil, and propanenitrile, caryophyllene oxide, (-)-caryophyllene, germacrene B, pogostol and α-humulene were representative ingredients of the WYJ oil. The ratio of sesquiterpenoids to monoterpenoids in PJH, WEZ, and WYJ were 2:1, 5:1 and 7:1, respectively. The antimicrobial activities of the three essential oils and of the six main ingredients were tested against two bacterial and one fungal strains using agar diffusion and broth dilution methods. The essential oil of PJH was shown to present a higher antimicrobial activity than that of WEZ and WYJ. Based on the Partial Least Square Model (PLS), the correlation between the antimicrobial activity of the tested oils and the identified chemical components was discussed and potential components of the antimicrobial activity were predicted according to Variable Importance in the Project (VIP) Value. The tested monoterpenes eucalyptol and isoborneol demonstrated a higher inhibitory activity than the sesquiterpenes germacrone, curdione and β-elemene. Therefore, the potent inhibitory effect of the PJH oil might be attributed to its higher content of monoterpenes. The MIC values for the essential oils and their ingredients ranged from 62.5 to 500 μg/mL.

Flavonoids play an important role in the treatment of various diseases, as they are able to inhibit reactive oxygen species, which cause damage to cells and tissues which may lead to increased risk of inflammatory diseases. Baicalin and baicalein, two flavonoids found in the roots ofScutellaria baicalensis, in the leaves ofThymus vulgarisandOroxylum indicum, were tested for their anti-inflammatory activity as well as for their cytotoxicity. Thereby the two compounds were investigated on Src tyrosine kinase inhibition and inhibition of production of interleukin (IL-6) in lipopolysaccharide- (LPS-) stimulated THP-1 cells. Additionally, the THP-1 cell line was used for the determination of the cytotoxicity. Both baicalin and baicalein showed some anti-inflammatory properties, while baicalein turned out to be the more active compound with higher inhibitory activities on both Src tyrosine kinase and production of cytokine IL-6. Baicalin and baicalein showed no signs of cytotoxicity in the MTS cytotoxicity assay in THP-1 cells.