Spirulina platensis exposed to various selenium （Se） concentrations （0, 10, 20, 40, 80, 150, 175, 200, 250 mg/L） accumulated high amounts of Se in a dose- and time-dependent manner. Under low Se concentrations （...Spirulina platensis exposed to various selenium （Se） concentrations （0, 10, 20, 40, 80, 150, 175, 200, 250 mg/L） accumulated high amounts of Se in a dose- and time-dependent manner. Under low Se concentrations （〈150 mg/L）, Se induced increases in biomass concentration, content of photosynthetic pigments, and activities of glutathione peroxidase （GPX）, superoxide dismutase （SOD）, catalase （CAT） and Gua-dep peroxidases （POD）, which indicates that antioxidant enzymes play an important role in protecting cells from Se stress. Higher Se concentrations （≥175 mg/L） led to higher Se accumulation and increases in activities of GPX, SOD, CAT and POD, but also induced lipid peroxidation （LPO） coupled with potassium leakage and decreases in biomass concentration and contents of photosynthetic pigment. The results indicate that increases in activities of the antioxidant enzymes were not sufficient to protect cell membranes against Se stress. Time-dependent variations in the activities of antioxidant enzymes, contents of chlorophyll a and carotenoid and the LPO level were also investigated under representative Se concentrations of 40 and 200mg/L. Opposite variation trends between SOD-CAT activities, and GPX-POD-APX activities were observed during the growth cycles. The results showed that the prevention of damage to cell membranes of S. platensis cells could be achieved by cooperative effects of SOD-CAT and GPX-POD-APX enzymes. This study concludes that S. platensis possessed tolerance to Se and could protect itself from phytotoxicity induced by Se by altering various metabolic processes.展开更多
Spirulina platensis is an excellent carrier of Se,and thus widely used in medical fields and as well as in the food industry.However,there is little information about the characteristics and bioactivity of selenium-co...Spirulina platensis is an excellent carrier of Se,and thus widely used in medical fields and as well as in the food industry.However,there is little information about the characteristics and bioactivity of selenium-containing S.platensis proteins(Se-SP).In this study,Se-SP with different molecular weights were isolated from selenium-enriched S.platensis,and the bioactivities(such as antioxidant and anti-inflammatory activities)of Se-SP were investigated.Se-SP3(with a molecular weight range of 20-48 kDa)showed better free radical scavenging ability(ABTS)than the other Se-SPs.In addition,Se-SP3 suppressed inflammatory cytokines,in which decreased by 74% interleukin 6(IL-6),42.28% tumor necrosis factor-α(TNF-α),69.07% content of malondialdehyde(MDA),40.45% interleukin-1β(IL-1β)relative to the LPS group.Moreover,Se-SP3 decreased the nitric oxide(NO)production by 64.84% compared with the LPS group and increased the activities of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px),indicating that Se-SP3 has excellent antioxidant and anti-inflammatory activities,and could be used as a functional food ingredient or natural medicine.展开更多
基金Supported by the National Natural Science Foundation of China and Guang-dong Province.
文摘Spirulina platensis exposed to various selenium （Se） concentrations （0, 10, 20, 40, 80, 150, 175, 200, 250 mg/L） accumulated high amounts of Se in a dose- and time-dependent manner. Under low Se concentrations （〈150 mg/L）, Se induced increases in biomass concentration, content of photosynthetic pigments, and activities of glutathione peroxidase （GPX）, superoxide dismutase （SOD）, catalase （CAT） and Gua-dep peroxidases （POD）, which indicates that antioxidant enzymes play an important role in protecting cells from Se stress. Higher Se concentrations （≥175 mg/L） led to higher Se accumulation and increases in activities of GPX, SOD, CAT and POD, but also induced lipid peroxidation （LPO） coupled with potassium leakage and decreases in biomass concentration and contents of photosynthetic pigment. The results indicate that increases in activities of the antioxidant enzymes were not sufficient to protect cell membranes against Se stress. Time-dependent variations in the activities of antioxidant enzymes, contents of chlorophyll a and carotenoid and the LPO level were also investigated under representative Se concentrations of 40 and 200mg/L. Opposite variation trends between SOD-CAT activities, and GPX-POD-APX activities were observed during the growth cycles. The results showed that the prevention of damage to cell membranes of S. platensis cells could be achieved by cooperative effects of SOD-CAT and GPX-POD-APX enzymes. This study concludes that S. platensis possessed tolerance to Se and could protect itself from phytotoxicity induced by Se by altering various metabolic processes.
基金financially supported by the Key Projects in Guangxi(2019GXNSFDA245008)Guangxi Natural Science Foundation(2017GXNSFAA198297)+1 种基金Guangxi Science and Technology Major Special Project(AA17204075,AA17202010-3)Guangxi Natural Science Foundation(2020GXNSFAA297038).
文摘Spirulina platensis is an excellent carrier of Se,and thus widely used in medical fields and as well as in the food industry.However,there is little information about the characteristics and bioactivity of selenium-containing S.platensis proteins(Se-SP).In this study,Se-SP with different molecular weights were isolated from selenium-enriched S.platensis,and the bioactivities(such as antioxidant and anti-inflammatory activities)of Se-SP were investigated.Se-SP3(with a molecular weight range of 20-48 kDa)showed better free radical scavenging ability(ABTS)than the other Se-SPs.In addition,Se-SP3 suppressed inflammatory cytokines,in which decreased by 74% interleukin 6(IL-6),42.28% tumor necrosis factor-α(TNF-α),69.07% content of malondialdehyde(MDA),40.45% interleukin-1β(IL-1β)relative to the LPS group.Moreover,Se-SP3 decreased the nitric oxide(NO)production by 64.84% compared with the LPS group and increased the activities of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px),indicating that Se-SP3 has excellent antioxidant and anti-inflammatory activities,and could be used as a functional food ingredient or natural medicine.
