Comparative analysis of chemical profiles, antioxidant, antibacterial, and anticancer effects of essential oils of two Thymus species from Montenegro.

The essential oils of Thymus vulgaris (TVEO) and Thymus serpyllum (TSEO) show different biological activities. The aim of the study was to evaluate the biological activities of TVEO and TSEO from Montenegro. The main components of TVEO were p-cymene (29.52%), thymol (22.8%) and linalool (4.73%) while the main components of TSEO were p-cymene (19.04%), geraniol (11,09%), linalool (9.16%), geranyl acetate (6.49%) and borneol (5.24%). Antioxidant activity determined via DPPH for TVEO was 4.49 and FRAP 1130.27, while for TSEO it was estimated that DPPH was 4.88 µL/mL and FRAP was 701.25 µmol FRAP/L. Both essential oils were active against all tested bacteria, with the highest level of sensitivity of E. coli with MIC of 1.5625 µL/mL. Essential oils showed strong cytotoxic effects on human cancer cell lines, with IC50 values ranging from 0.20 to 0.24 µL/mL for TVEO and from 0.32 to 0.49 µL/mL for TSEO. TVEO caused apoptosis in cervical adenocarcinoma HeLa cells through activation of caspase-3 and caspase-8, while TSEO caused apoptosis through caspase-3. EOs decreased levels of oxidative stress in normal MRC-5 cells. HeLa cells treated with TVEO had reduced MMP2 expression levels, while cells treated with TSEO had lowered MMP2 and MMP9 levels. The treatment of HeLa cells with TVEO increased the levels of miR-16 and miR-34a, indicating potential tumor-suppressive properties. Our findings suggest that Thymus essential oils may be considered as good candidates for further investigation as cancer-chemopreventive and cancer-therapeutic agents.

Heavy metal assessment in agricultural soils and vegetables in the vicinity of industrial pollutants in the Pljevlja municipality (Montenegro): ecological and health risk approach.

This paper aims to assess ecological and health risks associated with heavy metal (As, Hg, Cd, Pb, Cu, Zn, Cr) content in agricultural soils and vegetables (potato tuber, beetroot, onion bulb, carrot root) collected near the lead and zinc mine (MLZ), coal-fired power station (CFPS) and coal mine (CM) located in Pljevlja municipality (Montenegro). The ecological risk of soil was estimated using the ecological risk index (RI) and pollution load index (PLI). The health risk was evaluated through different soil exposure pathways (ingestion, inhalation, dermal contact) and vegetable consumption. The pollution indices RI and PLI indicated the highest contamination in MLZ study area followed by CM and CFPS areas. RI values revealed considerable contamination in MLZ and CM study areas, while CFPS area is moderately contaminated by heavy metals. According to PLI, soil in MLZ and CM areas is classified as polluted, while the soil in the vicinity of CFPS is classified as unpolluted. Non-carcinogenic and carcinogenic health risks through soil exposure were identified for both children and adults, in all investigated areas. Dermal contact was identified as the main contributor to carcinogenic risk. Dermal contact was also identified as the main exposure pathway for non-carcinogenic risk in MLZ area, while for CFPS and CM areas, ingestion was the main exposure route. As for vegetables, only Cu and Zn were detected in all examined vegetables. Non-cancerogenic health risk of edible vegetable consumption was found for children in all study areas, while there was no health risk for adults.

Biowaste as a Potential Source of Bioactive Compounds-A Case Study of Raspberry Fruit Pomace.

Raspberry fruit pomace, a byproduct of juice production, was studied as a potential source of antioxidant compounds. Target high-performance liquid chromatography analysis of important polyphenolic compounds (gallic, p-coumaric, caffeic, quercitrin, chlorogenic, and ellagic acid) was performed together with analysis of total phenolic content (TPC), total flavonoid content (TFC), total anthocyanins content (TAC), and antioxidant capacity (via ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays). The differences in polyphenolic content of Rubus idaeus L. pomace were evaluated following ultrasound-assisted extraction and conventional maceration with different organic solvents. Additionally, the yield of free phenolics was measured in hydrolyzed pomace extracts. The results obtained show that the ultrasound method maximizes the quantity of antioxidant compounds in terms of TPC (27.79 mg/L gallic acid equivalent (GAE)), TFC (8.02 mg/g quercetin equivalent (QE)), TAC (7.13 mg/L cyanidine-3-glucoside equivalent (C3G Eq)), caffeic (19.17 µg/g), chlorogenic (3.56 µg/g), ellagic (105.52 µg/g), and gallic acids (8.75 µg/g), as well as FRAP (1002.72 µmol/L) and DPPH assays (969.71 µmol/mL vitamin C equivalent (vit C Eq); 567.00 µmol/100 g Trolox equivalent (TE)). On the other hand, conventional maceration maximizes the yield of quercetin and p-coumaric acid. In terms of biowaste valorization, raspberry fruit pomace has a promising industrial potential and may prove to be useful in the development of antioxidant dietary supplements.

Effect of heavy metals on stem anatomical characteristics of Trapa natans L from Skadar Lake (Montenegro)

This study aimed to analyze stem anatomical characteristics of Trapa natans from five Skadar Lake locations (L1 - Milovica bay, L2 ­ inflow of the Moraca river, L3 - Kamenik, L4 - Grmozur, L5 - Lipovik) with different concentrations of Cu, Mn, Zn, Co and Pb, during the summer period of the year 2012. Cross sections of stem were made using cryotechnic procedure. For all analyzed quantitative anatomical parameters, the minimum values at the location L2 were recorded, with the presence of maximum content for all investigated metals in stem of Trapa natans. On the other hand, except for cobalt, at the location L4 the minimum concentration for all investigated metals were recorded. Plants collected from this location have the largest average values of the most measured anatomical parameters. The results of Discriminant Analysis showed that plants from different location could be clearly classified into three groups according to their stem quantitative anatomical characteristics which corresponds with heavy metals content. Our research also showed that there is no statistically significant correlation between the content of most investigated metals (Co, Cu, Pb and Zn) and the values of anatomical parameters. Statistically significant negative correlation was found between Mn content in stem and values of two anatomical characters (stem cross-sectional area and Mn content, r = - 0.88; p < 0.05; number of hypodermal cell layers and Mn content, r = - 0.90; p < 0.05).

Levels and distribution of cobalt and nickel in the aquatic macrophytes found in Skadar Lake, Montenegro.

Macrophytes react to changes in the quality of the environment in which they live (water/sediment), and they are good bioindicators of surface water conditions. In the present study, the content of the metals cobalt (Co) and nickel (Ni) was determined in the sediment, the water, and different organs of macrophytes from six localities around Lake Skadar, across four different seasons of year. The aquatic macrophytes that have been used as bioindicator species in this study are Phragmites australis (an emerged species), Ceratophyllum demersum (a submerged species), and Lemna minor (a floating species). The aim of this study was to determine the distribution of metals in macrophyte tissues and also to discover the degree of bioaccumulation of the investigated metals, depending both on the location and on the season. The content of Co and Ni in the examined parts of the macrophytes was in the range of 0.04-8.78 and 0.30-28.5 ppm, respectively. The greatest content of the investigated metal in the organs of P. australis and C. demersum was recorded at the beginning of and during the growing season. Greater concentrations of metals in the tissue of L. minor were observed at the end of the growing season.