MERCURY IN BIOINDICATORS OF THE COASTAL WATERS OF VLADIVOSTOK IN SUMMER 2020

Определены концентрации ртути в талломах массовых видов водорослей-биоиндикаторов родов Ulva lactuca, Ulvaria splendens, Sargassum miyabei, Sargassum pallidum, из прибрежных вод вокруг г. Владивостока Японского моря за летний период 2020 г. Содержание Hg варьируется от 5,8 до 41,4 нг/г сухой массы. Наибольшая концентрация наблюдается в ульве, отобранной из района бывшего полигона ТБО «Горностай», где ранее отмечались повышенные концентрации Cu, Pb, Fe, Zn. Отмечена тенденция уменьшения концентраций ртути в водорослях с июня по июль, как для ульвы, так и для саргассума. Водоросли вокруг Владивостока содержат очень низкие концентрации ртути и не превышают ПДК промысловых водорослей – 500 нг/г сухой массы. Полученные концентрации соответствуют величине Q1 – 25 процентилю общемировой выборки для зеленых и в основном Q1 для бурых, что говорит об отсутствии загрязнения ртутью литоральной зоны вокруг г. Владивосток в исследуемый период. The concentrations of mercury in mass species of algae - bioindicators of the genera Ulva lactuca, Ulvaria splendens, Sargassum miyabei, Sargassum pallidum, from coastal waters around Vladivostok, the Sea of Japan in summer of 2020 were determined. The Hg concentrations varies from 5.8 to 41.4 ng / g dry weight. The highest concentration is observed in the Ulva, taken from the area of the former landfill "Gornostay", where previously there were increased concentrations of Cu, Pb, Fe, Zn in algae. A tendency of a decrease in mercury concentrations in algae from June to July was noted for both Ulva and Sargassum in connection of atmosphera precipitations decreasing. Algae around Vladivostok contained very low concentrations of mercury and did not exceed the MPC for commercial algae - 500 ng / g dry weight. The obtained concentrations correspond to the value of Q1 - the 25th percentile of the global sample for green algae and mainly Q1 for brown ones, which indicates the absence of mercury contamination of the littoral zone around Vladivostok during the study period.

Sargassum miyabei Yendo Brown Algae Exert Anti-Oxidative and Anti-AdipogenicEffects on 3T3-L1 Adipocytes by Downregulating PPARγ

Background and objectives: Sargassum miyabei Yendo, belonging to the family Sargassaceae, has been reported to have various biological effects such as anti-tyrosinase activity and anti-inflammation. However, the anti-obesity effect of Sargassum miyabei Yendo has not yet been reported. Materials and Methods: The effects of Sargassum miyabei Yendo extract (SME) on 3T3-L1 adipocytes were screened by3-(4,5)-dimethylthiazo-2-yl-2,5-diphenyltetrazolium bromide (MTT), Oil red O staining, western blot, and Real-time reverse transcription polymerase chain reaction analyses. Results: Here, we show that SME had potent 2,2’-azinobis-3-ehtlbezothiazoline-6-sulfonic acid radical decolorization (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity with half maximal inhibitory concentration (IC50) value of 0.2868 ± 0.011 mg/mL and 0.2941 ± 0.014 mg/mL, respectively. In addition, SME significantly suppressed lipid accumulation and differentiation of 3T3-L1 preadipocytes, as shown by Oil Red O staining results. SME attenuated the expression of adipogenic- and lipogenic-related genes such as peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT-enhancer-binding protein alpha (C/EBPα), CCAAT-enhancer-binding protein delta (C/EBPδ), adiponectin, adipose triglyceride lipase (ATGL), fatty acid synthase (FAS), hormone-sensitive lipase (HSL), and lipoprotein lipase (LPL). Conclusions: These findings suggest that SME may have therapeutic implications for developing a new anti-obesity agent.

Inhibitory Effects of a Sargassum miyabei Yendo on Cutibacterium acnes-Induced Skin Inflammation

Acne vulgaris is a chronic inflammatory condition of skin sebaceous follicles. To explore its effects on acne vulgaris, we investigated the antibacterial and anti-inflammatory activities of Sargassum miyabei Yendo (a brown alga) ethanolic extract (SMYEE) on Cutibacterium acnes (C. acnes)-stimulated inflammatory responses, both in vivo and in vitro. To induce inflammation in vivo, C. acnes was intradermally injected into the dorsal skin of mice, to which SMYEE was applied. The antimicrobial activity of SMYEE was evaluated by the determination of minimum inhibitory concentrations (MICs). To explore in vitro anti-inflammatory effects, HaCaT cells were stimulated with C. acnes after treatment with SMYEE. The levels of IL-8 and the underlying molecular effects in C. acnes-stimulated HaCaT cells were assessed by enzyme-linked immunosorbent assay, Western blotting, and an electrophoretic mobility shift assay. Mouse skin lesions improved after treatment with SMYEE (50 μg/mouse). Neutrophil infiltration was significantly reduced in SMYEE-treated compared to SMYEE-untreated skin lesions. SMYEE reversed the C. acnes-induced increase in IL-8 levels in HaCaT cells and suppressed dHL-60 cell migration. SMYEE also inhibited C. acnes-induced phosphorylation of the extracellular signal-regulated kinase and inhibited activator protein-1 signaling. SMYEE may be a useful treatment for C. acnes-induced acne vulgaris.

Assessment of ecological state of the Posyet Bay (the Sea of Japan) by heavy metals content in brown algae

The paper contains the study of heavy metals in three species - Sargassum miyabei , Sargassum pallidum , Cystoseira crassipes in the coastal waters of the Posyet Bay. The analysis of the spatial distribution of trace elements revealed the highest contents of zinc, copper and nickel in the Troitsa Bight, due to recreational pressure and a high concentration of nickel and cadmium in Sivuchya Bight that was caused by transboundary atmospheric transport. All of detected concentrations exceed natural background values for the North-Western part of the Sea of Japan. The authors show that there has been a distinct change in the environmental situation in the the Posyet Bay since 1998: the concentration of lead has sharply decreased, the content of zinc, copper and cadmium has decreased, it could be connected with influence reduction in the free economic zone, located on the Chinese side on the Tumannaya River.