Nowadays, there is an increasing interest in the use of natural botanical herbal extracts as active ingredients of functional cosmetic and pharmaceutical products. Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’ is an indigenous cultivar of lavandin and, together with the common lavender (L. angustifolia), it has been widely cultivated in Croatia. The present study was undertaken to evaluate and compare the possible inhibitory effects of Lavandula ethanolic extracts on elastase and tyrosinase which are important therapeutic targets. In terms of anti-ageing, finding inhibitors of elastase enzyme can be useful to prevent loss of skin elasticity and wrinkle formation, but also an anti-elastase agent may be useful in the treatment of inflammation. Inhibition of elastase activity by the leaf, flower and inflorescence stalk extracts of Lavandula x intermedia ‘Budrovka’ at 1mg/mL was found to be 100%, 77.7% and 18.6%, respectively, while the inhibitory percentages for L. angustifolia extracts were 100% (leaf), 65.8% (flower) and 15.1% (inflorescence stalk). Investigation of tyrosinase inhibitors may lead to development of novel agents for the treatment of hyperpigmentation as well as skin-whitening agents. In the tyrosinase inhibition assay, flower extracts (1mg/mL) of L. x intermedia ‘Budrovka’ and L. angustifolia were the most effective, exhibiting similar inhibitory effects of 70.4% and 72.9%, respectively, while the leaf and inflorescence stalk extracts exerted lower activity. According to the results of the present in vitro enzyme inhibition studies, flowers and leaves of both Lavandula taxa may be promising sources of active ingredients in dermatological preparations.

The genus Micromeria (Lamiaceae) is represented by nine species in Croatia, three of which (M. croatica (Pers.) Schott, M. dalmatica Benth. and M. pseudocroatica Silic) are endemic [1]. Micromeria species are perennial herbs or dwarf shrubs growing mostly in Mediterranean region. Some of them are traditionally used against heart disorders, headache, colds, wounds and skin infections, as well as condiments [2]. In the present paper, antioxidant activities of M. croatica, M. juliana and M. thymifolia were evaluated using five in vitro antioxidant assays, in comparison with plant polyphenolic constituents and reference antioxidants. All studied plant extracts exhibited considerable activity to scavenge DPPH and hydroxyl free radicals, reducing power, iron-chelating ability and total antioxidant capacity in order: M. croatica > M. juliana > M. thymifolia. Among the tested plants, ethanolic extract of M. croatica was found to be the most effective DPPH radical scavenger (IC50 4.7 μg/ml), even stronger than BHT (IC50 6.5 μg/ml). The highest activity toward hydroxyl free radicals was recorded for the same extract (IC50 249.65 μg/ml). Additionally, it also showed the strongest reducing power (IC50 9.64 μg/ml) and iron-chelating ability (IC50 227.47 μg/ml). In phosphomolybdenum assay, M. croatica displayed twofold lower total antioxidant capacity than ascorbic acid. Total polyphenol (9.69-13.66%), phenolic acid (5.26-6.84%), flavonoid (0.01-0.09%) and tannin contents (3.07-6.48%) in dried plant samples were spectrophotometrically determined. A good correlation between antioxidant activities and contents of phenolic acids and tannins was established, indicating their responsibility for antioxidant capabilities of Micromeria species. References: 1. Lovasen-Eberhardt, Ž. (2000) Nat. Croat. 9:19-20. 2. Duru, M.E. (2004) J. Ethnopharmacol. 94:43-48.

Micromeria species are traditionally used as expectorant, antispasmodic and stimulant agents as well as condiments [1]. Our study aimed to evaluate in vitro modulation effects of three Micromeria ethanolic extracts on interleukin-6 (IL-6) production in comparison with hydroxycinnamic acids. IL-6 is a cytokine with various essential biological activities. It plays important roles in the regulation of immune response and inflammation [2]. Total contents of hydroxycinnamic acids were spectrophotometrically determined in aerial plant parts of M. croatica (6.8%), M. juliana (5.4%) and M. thymifolia (5.3%). TLC analysis showed the presence of caffeic, chlorogenic and rosmarinic acids in studied plant extracts. Modulation of IL-6 production in LPS-stimulated male Balb/C mice splenocytes by plant extracts (18.75–300µg/mL), as well as caffeic acid, chlorogenic acid and rosmarinic acid (125–2000µM) was exhibited using enzyme-linked immunosorbent assay (ELISA). None of the investigated samples showed cytotoxic effect or inhibition of cell growth of human THP-1 and HepG2 cell lines, as well as on mouse splenocytes (where we observed increased absorbance) by MTS citotoxicity test. In tested concentrations, all extracts and hydroxycinnamic acids inhibited production of IL-6 in the range of 9.5–100% and 30.6–100%, respectively. Among the extracts, the activity decreased in order M. juliana >M. croatica >M. thymifolia, percentages of inhibition were 56.6%, 54.3% and 42.1% at concentration of 75µg/mL. These findings suggest that Micromeria ethanolic extracts possess anti-inflammatory activity, which could be attributed to the presence of hidroxycinnamic acids.

Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’ is an indigenous cultivar of lavandin which has been widely cultivated in Croatia as an essential oil crop. Our previous studies revealed strong antioxidant and antibacterial activities of its various extracts [1, 2]. Continuing our evaluation of biomedical potential of lavandin ‘Budrovka’, the present work focuses on the investigation of antifungal activity. For this purpose, liquid ethanolic extracts were prepared from different plant parts: flowers, inflorescence stalks and leaves. Employing the agar-well diffusion method, the extracts were screened for antifungal activity against eight yeast strains (Candida albicans, C. glabrata, C. krusei, C. kefyr, C. tropicalis, Cryptococcus neoformans, Blastoschizomyces capitatus and Hansenula anomala) and five molds (Aspergillus fumigatus, A. niger, Fusarium oxysporum, Penicillium citrinum and Trichoderma viride). Overall, the tested extracts were more effective against yeasts than molds. The measured zones of inhibition of fungal growth strongly indicated that the antifungal constituents reside primarily in the flower (ZI: 10–21mm), whereas the inflorescence stalk and leaves extracts exhibited considerably weaker activity (ZI ≤10). Minimal inhibitory concentrations (MIC, vol%) and minimal fungicidal concentrations (MFC, vol%) for each strain were determined by the broth dilution assay. Results obtained for flower, leaf and inflorescence stalk extracts revealed that Candida krusei was the most sensitive tested strain (MIC: 0.05, 8 and 9%, respectively), while Aspergillus niger was the most resistant (MIC: 4, 30 and 35%, respectively). In conclusion, the present study highlighted the antifungal potential of Lavandula x intermedia ‘Budrovka’ flowers.