Search

The polyphenolic composition and anti-inflammatory activity of selected Thymus species (T. longicaulis C. Presl, T. praecox Opiz subsp. polytrichus (A. Kerner Ex Borbas) Jalas, T. pulegioides L., T. serpyllum L. subsp. serpyllum and T. striatus Vahl) was studied in comparison with T. vulgaris, as an officinal medicinal plant, to evaluate the biomedical potential of these Croatian wild-growing species. This paper provides a first insight into the polyphenolic profiles of T. praecox subsp. polytrichus and T. striatus. Also, some flavone and hydroxycinnamic derivatives were at first identified in the other studied species by LC-DAD-ESI–MS/MS analysis. Rosmarinic acid and glycosides of scutellarein and luteolin were found to be the most abundant polyphenolic constituents. The Thymus extracts inhibited Src tyrosine kinase activity and they reduced the production of proinflammatory cytokine interleukin-6 in Balb/C mice splenocytes. The obtained results highlighted T. longicaulis as a potential source of herbal drugs with anti-inflammatory properties and/or novel functional food rich in flavonoids and phenolic acids.

In the search for new natural resources with promising biological activity, chemical composition as well as antibacterial, antifungal and antioxidant activities of the essential oil from Croatian indigenous cultivar of lavandin (Lavandula × intermedia‘Budrovka’) were studied for the first time and compared with those of lavender (L. angustifolia) cultivated under the same pedo-climatic conditions of central Croatia. Forty compounds were identified in the studied Lavandula essential oils by GC–MS analysis. Linalool (57.1%), linalyl acetate (9.8%) and 1,8-cineole (8.4%) were the most abundant compounds of lavandin ‘Budrovka’ oil while lavender oil contained mainly linalool (54.0%), linalyl acetate (11.6%) and lavandulol (6.6%). Both essential oils were characterized by a very low amount of camphor (≤0.3%). The antimicrobial activities of two Lavandula essential oils and their dominant constituents were evaluated against 30 medically important pathogens and microbial contaminants of food, cosmetic and pharmaceutical products using agar well diffusion and broth dilution methods. L. × intermedia ‘Budrovka’ essential oil showed a broad-spectrum of antibacterial (MICs 0.25–2.5 mg/mL) and antifungal (MICs 0.1–2 mg/mL) activities, being generally more than or at least as effective as those from L. angustifolia. Among the two dominant compounds which were also tested comparatively and found to exhibit antimicrobial effect, linalool has been pointed out as much more potent agent then linalyl acetate. Antioxidant studies based on DPPH assay indicated that the lavandin ‘Budrovka’ essential oil has significantly stronger antioxidant properties than lavender essential oil (IC50 21.6 mg/mL and 27.7 mg/mL, respectively). This study highlighted Croatian indigenous cultivar lavandin ‘Budrovka’ as a rich source of essential oil with pronounced antimicrobial properties due to abundance of linalool and indicated its potential use as biopreservative in food, pharmaceutical and cosmetic products or as natural remedy with promising health benefit.

The present study aimed to evaluate antioxidant and acetylcholinesterase (AChE) inhibitory activities of the ethanolic extracts of six selectedThymusspecies growing in Croatia (T. longicaulis,T. praecoxsubsp.polytrichus,T. pulegioides,T. serpyllumsubsp.serpyllum,T. striatus, andT. vulgaris). Antioxidant effectiveness was assessed using six different assays, in comparison with rosmarinic acid, luteolin, and reference antioxidants. All testedThymusextracts possessed DPPH (IC50= 3–6 μg/mL) and nitric oxide (IC50= 70–177 μg/mL) free radical scavenging activities, strong reducing properties (IC50= 11–15 μg/mL), ferrous ion chelating activity (IC50= 126–389 μg/mL), ability to inhibit lipid peroxidation (IC50= 34–80 μg/mL), and high total antioxidant capacities (238–294 mg AAE/g). AChE inhibitory activity was examined using Ellman's colorimetric method and all tested extracts showed anti-AChE activity in a dose dependent manner. The values of 10–28%, 23–39%, and 64–86% were obtained for tested concentrations of 0.25, 0.5, and 1 mg/mL, respectively. Additionally, the contents of total hydroxycinnamic derivatives, flavonoids, and tannins in dried plant samples were determined spectrophotometrically. Our results highlightedThymusspecies as a rich source of natural antioxidants and AChE inhibitors that could be useful in preventing and treating Alzheimer’s disease and other neurodegenerative disorders.

We investigated the effect of natural sweetener Stevia rebaudiana and its constituent stevioside in cisplatin (CP)-induced kidney injury. Male BALB/cN mice were orally administered 10, 20, and 50 mg/kg body weight of Stevia rebaudiana ethanol extract (SE) or stevioside 50 mg/kg, 48 h after intraperitoneal administration of CP (13 mg/kg). Two days later, CP treatment resulted in histopathological changes showing kidney injury. Increased expression of 4-hydroxynonenal (4-HNE), 3-nitrotyrosine (3-NT), and heme oxygenase-1 (HO-1) in mice kidneys suggested oxidative stress. CP treatment also increased renal expression of nuclear factor-kappaB (NF-κB) p65 subunit and phosphorylated inhibitor of NF-κB (IκBα), as well as expression of pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α). Induction of apoptosis and inhibition of the cell cycle in kidneys was evidenced by increased expression of p53, Bax, caspase-9, and p21, proteolytic cleavage of poly (ADP-ribose) polymerase (PARP), with concomitant suppression of Bcl-2 and cyclin D1 expression. The number of apoptotic cells in kidneys was also assessed. CP administration resulted in activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and signal transducer and activator of transcription 3 (STAT3). Both SE and stevioside attenuated CP nephrotoxicity by suppressing oxidative stress, inflammation, and apoptosis through mechanism involving ERK1/2, STAT3, and NF-κB suppression.

Migraine is one of the most common neurological disorder, which has long been related to brain serotonin (5-HT) depletion and neuro-inflammation. Despite many treatment options are available, the frequent occurrence of unacceptable adverse effects further supports the research toward nutraceuticals and herbal preparations, among which Tanacetum parthenium and Salix alba showed promising anti-inflammatory and neuro-modulatory activities. The impact of extract treatment on astrocyte viability, spontaneous migration and apoptosis was evaluated. Anti-inflammatory/anti-oxidant effects were investigated on isolated rat cortexes exposed to a neurotoxic stimulus. The lactate dehydrogenase (LDH) release, nitrite levels and 5-HT turnover were evaluated, as well. A proteomic analysis was focused on specific neuronal proteins and a fingerprint analysis was carried out on selected phenolic compounds. Both extracts appeared able to exert in vitro anti-oxidant and anti-apoptotic effects. S. alba and T. parthenium extracts reduced LDH release, nitrite levels and 5-HT turnover induced by neurotoxic stimulus. The downregulation of selected proteins suggest a neurotoxicity, which could be ascribed to an elevated content of gallic acid in both S. alba and T. parthenium extracts. Concluding, both extracts exert neuroprotective effects, although the downregulation of key proteins involved in neuron physiology suggest caution in their use as food supplements.

BACKGROUND: Micromeria croatica (Pers.) Schott is an aromatic plant from Lamiaceae family previously found to possess potent in vitro antioxidant activity which is mainly attributed to the high level of polyphenolic substances. The aim of this study was to investigate the hepatoprotective activity and possible underlying mechanisms of Micromeria croatica ethanolic extract (MC) using a model of carbon tetrachloride (CCl4)-induced liver injury in mice. METHODS: Male BALB/cN mice were randomly divided into seven groups: control group received saline, MC group received ethanolic extract of M. croatica in 5% DMSO (100 mg/kg b.w., p.o.), and CCl4 group was administered CCl4 dissolved in corn oil (2 mL/kg, 10% v/v, ip). MC50, MC200 and MC400 groups were treated with MC orally at doses of 50, 200 and 400 mg/kg once daily for 2 consecutive days, respectively, 6 h after CCl4 intoxication. The reference group received silymarin at dose of 400 mg/kg. At the end of experiment, blood and liver samples were collected for biochemical, histopathological, immunohistochemical and Western blot analyses. In addition, major phenolic compounds in MC were quantified by HPLC-DAD. RESULTS: CCl4 intoxication resulted in liver cells damage and oxidative stress and triggered inflammatory response in mice livers. MC treatment decreased ALT activity and prevented liver necrosis. Improved hepatic antioxidant status was evident by increased Cu/Zn SOD activity and decreased 4-hydroxynonenal (4-HNE) formation in the livers. Concomitantly, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were overexpressed. The hepatoprotective activity of MC was accompanied by the increase in nuclear factor-kappaB (NF-κB) activation and tumor necrosis factor-alpha (TNF-α) expression, indicating amelioration of hepatic inflammation. Additionally, MC prevented tumor growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) expression, suggesting the potential for suppression of hepatic fibrogenesis. CONCLUSION: These results of the present study demonstrated that MC possesses in vivo antioxidant and anti-inflammatory activity and exhibits antifibrotic potential, which are comparable to those of standard hepatoprotective compound silymarin.

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 inhibitors and antioxidants that could be useful in the prevention and treatment of Alzheimer’s and other related diseases.

In this work, qualitative and quantitative analyses of total hydroxycinnamic acid (THA) derivatives in leaves, flowers and aerial parts of 32 Lamiaceae species were carried out. HPTLC analysis of plant material indicated rosmarinic acid as the main phenolic acid in 22 Lamiaceae plant extracts, while chlorogenic acid predominated in other 10 investigated species. Determination of THA in different medicinal plants was performed by colorimetric methods using chromogenic system of HCl-NaNO2–Na2MoO4–NaOH and two standards: rosmarinic acid (R-THA procedure) and chlorogenic acid (C-THA procedure). Performance characteristics of THA assay were established, and the quality of the analytical procedures was evaluated using valuable prevalidation strategy. Good quality of the measurements at the lower analyte level, excellent resolution of blank and analyte signals, homogenous data material, ideal linear calibration and analytical evaluation functions, very low limit of detection [L D(R-THA) = 0.53 μg; L D(C-THD) = 1.75 μg] and limit of quantitation [L Q(R-THD) = 1.76 μg; L Q(C-THD) = 4.21 μg], and high precision and accuracy confirmed the high quality of investigated procedures as valuable tools in THA analysis. Application of these prevalidated, simple and rapid analytical methods revealed that the studied Lamiaceae plants differ greatly in their THA contents, ranging from 1.95 % (Acinos arvensis) to 11.03 % (Satureja subspicata). The results obtained from qualitative and quantitative analysis provided new information regarding phytochemical characterization of Lamiaceae species originating from Croatia and highlighted members of the genus Micromeria, Origanum, Melissa and Satureja as rich sources of hydroxycinnamic acids.