Ascophyllum nodosum (Linnaeus) Le Jolis from Arctic: Its Biochemical Composition, Antiradical Potential, and Human Health Risk

Ascophyllum nodosum is a brown seaweed common in Arctic tidal waters. We have collected A. nodosum samples from the Barents Sea (BS), Irminger Sea (IS), and Norwegian Sea (NS) in different reproductive stages and have evaluated their biochemical composition, radical scavenging potential, and health risks. The total content of dominating carbohydrates (fucoidan, mannitol, alginate, and laminaran) ranged from 347 mg/g DW in NS to 528 mg/g DW in BS. The proportion of two main structural monosaccharides of fucoidan (fucose and xylose) differed significantly between the seas and reproductive phase, reaching a maximum at the fertile phase in the BS sample. Polyphenols and flavonoids totals were highest in NS A. nodosum samples and increased on average in the following order: BS < IS < NS. A positive correlation of free radical scavenging activity for seaweed extracts with polyphenols content was observed. The concentration of elements in A. nodosum from the Arctic seas region was in the following order: Ca > Mg > Sr > Fe > Al > Zn > As total > Rb > Mn > Ba > Cu > Co. Seaweeds from BS had the lowest metal pollution index (MPI) of 38.4. A. nodosum from IS had the highest MPI of 83. According to the calculated target hazard quotient (THQ) and hazard index (HI) values, Arctic A. nodosum samples pose no carcinogenic risk to adult and child health and are safe for regular consumption. Our results suggest that the Arctic A. nodosum has a remarkable potential for food and pharmaceutical industries as an underestimated source of polysaccharides, polyphenols, and flavonoids.

Arctic Edible Brown Alga Fucus distichus L.: Biochemical Composition, Antiradical Potential and Human Health Risk

Fucus distichus L. is the dominant canopy-forming macroalga in the rocky intertidal areas of the Arctic and Subarctic. In the present study, the impact of the geographic location of F. distichus collected in the Baffin Sea (BfS), Norwegian Sea (NS), White Sea (WS), and Barents Sea (BS) on the variations in biochemical composition, antiradical properties, and health risk was evaluated. The accumulation of main carbohydrates (fucoidan, mannitol, and alginic acid) varied from 335 mg/g dry weight (DW) in NS to 445 mg/g DW in BS. The highest level of the sum of polyphenols and flavonoids was found in samples of F. distichus from WS and was located in the following ranking order: BS < BfS < NS < WS. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of seaweed is correlated with its phenolic content. It is notable that in most Arctic F. distichus samples, Cd, Cr, Pb, and Ni were not detected or their concentrations were below the limit of quantification. According to calculated targeted hazard quotient and hazard index values, all studied samples of Arctic F. distichus are safe for daily consumption as they do not pose a carcinogenic risk to the health of adults or children. The results of this study support the rationale for using Arctic F. distichus as a rich source of polysaccharides, polyphenols, and flavonoids with important antiradical activity. We believe that our data will help to effectively use the potential of F. distichus and expand the use of this algae as a promising and safe raw material for the food and pharmaceutical industries.

Chemical composition and cardiotropic activity of Ziziphora clinopodioides subsp. bungeana (Juz.) Rech.f

ETHNOPHARMACOLOGICAL RELEVANCE

Ziziphora clinopodioides subsp. bungeana (Juz.) Rech.f. is a subshrub that is widely distributed in China, Kazakhstan, Kyrgyzstan, Mongolia, Russia, Tajikistan, Turkmenistan, and Uzbekistan. The species is used in traditional medicine for the relief of symptoms connected to cardiovascular diseases like coronary heart disease or hypertension.

AIM OF THE STUDY

was to validate traditional use of Z. clinopodioides subsp. bungeana for the treatment of coronary hearth diseases using in vivo models and to find active compounds responsible for the activity.

MATERIALS AND METHODS

Multiple extracts were obtained from the aerial parts of Z. clinopodioides subsp. bungeana using maceration, liquid-liquid extraction, CO2 extraction and ultrasound-assisted extraction. Preliminary screening studies for the evaluation of the efficacy of Z. clinopodioides subsp. bungeana extracts on the model of hemic hypoxia were performed. The most effective samples were selected and included in the main study. Stage 2 of the study evaluated the cardiotropic activity of the selected extracts on a model of chronic heart failure. Preparations were administered to animals intragastrically once a day for 28 days. For the isolation of individual compounds plant material was extracted with 96% ethanol. The obtained crude extract was sequentially extracted with n-hexane and dichloromethane and separated by chromatography on a Diaion HP-20 column. The obtained fractions were further subjected to Sephadex LH-20 column chromatography and eluted isocratically with 96% ethanol (EtOH) to yield subfractions, which were further separated by preparative HPLC to obtain 13 individual compounds.

RESULTS

Extracts obtained from Ziziphora clinopodioides subsp. bungeana (Juz.) Rech.f. herb were subjected to pharmacological screening for the evaluation of their efficacy on hemic hypoxia. Based on the obtained results, out of the sixteen tested extracts two (AR and US 60%) were selected for further evaluation of their cardiotropic activity. Modeling of chronic heart failure was carried out in accordance with the following stages: 1) anesthesia with chloral hydrate at a dose of 450 mg/kg, intraperitoneally, 2) artificial ventilation of the lungs, 3) thoracotomy, 4) modeling of permanent ischemic or ischemic-reperfusion damage. Both extracts effected the indicators of contraction and output, comparable to the reference drug - Monopril. Based on the extraction methods used to obtain RAF and US60 and data from the literature, it can be assumed that they contain compounds with medium polarity, including polyphenols and terpenoids. At the next stage three previously undescribed monoterpenoid derivatives - Ziziphoric acid (1), Ziziphoroside D (2) and 6'-malonylziziphoroside A (3), along with two previously described megastigmane glucosides - blumenol C glucoside (4), blumenol C 9-O-(6'-O-malonyl-beta-D-glucopyranoside (5) and two previously described monoterpenoids 7a-hydroxymintlactone (6), 7-hydroxypiperitone (7) together with six polyphenols - pinocembrine-7-O-rutinoside (8), chrysine-7-O-rutinoside (9), acacetin-7-O-rutinoside (10), luteolin-7-O-rutinoside (11), rutin (12) and rosmarinic acid (13) were isolated from Z. clinopodioides subsp. bungeana extracts.

CONCLUSION

Our results support the traditional use of Z. clinopodioides subsp. bungeana for the treatment of coronary diseases. As a result of Z. clinopodioides subsp. bungeana extracts screening in vivo, two extracts were selected as potential cardiotropic agents. Phytochemical analysis of the plant material led to the isolation of five terpenoid derivatives, two megastigmane glycosides, five flavonoids and one cinnamic acid derivative, which could be responsible for the reported biological activity. Future experiments are required to understand the mechanisms of action for the isolated compounds.

The Impact of Natural Deep Eutectic Solvents and Extraction Method on the Co-Extraction of Trace Metals from Fucus vesiculosus

In recent years, natural deep eutectic solvents (NADES) have been widely investigated for the extraction of food and medicinal plants as well as seaweeds. However, the ability of NADES for trace elements co-extraction from natural sources is not well investigated. The aim of this study was to investigate the ability of common NADES for trace elements co-extraction from Fucus vesiculosus. All of the tested NADES did not recover As and Co (concentration Collapse

Key Words

• Fucus vesiculosus
• NADES
• extraction
• hazard quotient
• health risk
• natural deep eutectic solvents
• trace elements
• trace metals

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MESH Headings

• Deep Eutectic Solvents
• Fucus
• Plant Extracts
• Solvents
• Water

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Grants

• 121091600104-7 Ministry of Science and Higher Education of the Russian Federation within the framework of the Government Assignment to the Murmansk Marine Biological Institute Russian Academy of Sciences
• 075-15-2021-685; dated 26 July 2021 on the provision of the federal budget grants Ministry of Science and Higher Education of the Russian Federation

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Affiliation(s)

Alexander N. Shikov Murmansk Marine Biological Institute of the Russian Academy of Sciences (MMBI RAS), Vladimirskaya, 17, 183010 Murmansk, Russia; (E.D.O.); (O.N.P.) Department of Pharmaceutical Formulations, St. Petersburg State Chemical Pharmaceutical University, Prof. Popov, 14, 197376 Saint-Petersburg, Russia;
Ekaterina D. Obluchinskaya Murmansk Marine Biological Institute of the Russian Academy of Sciences (MMBI RAS), Vladimirskaya, 17, 183010 Murmansk, Russia; (E.D.O.); (O.N.P.)
Elena V. Flisyuk Department of Pharmaceutical Formulations, St. Petersburg State Chemical Pharmaceutical University, Prof. Popov, 14, 197376 Saint-Petersburg, Russia;
Inna I. Terninko Core Shared Research Facilities “Analytical Center”, St. Petersburg State Chemical Pharmaceutical University, Prof. Popov, 14, 197376 Saint-Petersburg, Russia; (I.I.T.); (Y.E.G.)
Yulia E. Generalova Core Shared Research Facilities “Analytical Center”, St. Petersburg State Chemical Pharmaceutical University, Prof. Popov, 14, 197376 Saint-Petersburg, Russia; (I.I.T.); (Y.E.G.)
Olga N. Pozharitskaya Murmansk Marine Biological Institute of the Russian Academy of Sciences (MMBI RAS), Vladimirskaya, 17, 183010 Murmansk, Russia; (E.D.O.); (O.N.P.)

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The Biochemical Composition and Antioxidant Properties of Fucus vesiculosus from the Arctic Region

Fucus vesiculosus is one of the most prominent brown algae in the shallow waters of the seas of the Arctic region (Barents (BS), White (WS), Norwegian (NS), and Irminger (IS)). The aim of this study was to determine the biochemical composition of F. vesiculosus from the Arctic at different reproductive phases, and to evaluate the antioxidant properties of F. vesiculosus extracts. The amounts of monosaccharides, phlorotannins, flavonoids, and ash and the mineral composition significantly varied in the algae. A strong correlation was established between monosaccharide, phlorotannin, and flavonoid accumulation and water salinity (Pearson’s correlation coefficients r = −0.58, 0.83, and 0.44, respectively; p < 0.05). We noted a negative correlation between the antioxidant activity and the amount of the structural monosaccharides of fucoidan (r = −0.64). A positive correlation of phlorotannins and flavonoids with antioxidant power was confirmed for all samples. The ash accumulation was relatively lower in the sterile phase for the algae from the BS and WS. The correlation between the Metal Pollution Index (MPI) and the reproductive phases was medium with high fluctuation. Meanwhile, the MPI strongly correlated with the salinity and sampling site. The gradient of the MPI values across the sea was in the following ranking order: BS < WS < NS < IS. Taken together, and based on our data on the elemental contents of F. vesiculosus, we believe that this alga does not accumulate toxic doses of elements. Therefore, the Arctic F. vesiculosus could be safely used in food and drug development as a source of active biochemical compounds and as a source of dietary elements to cover the daily nutritional requirements of humans.