Antimicrobial, antioxidant, cytotoxic and anticholinesterase activities of water-soluble polysaccharides extracted from microalgae Isochrysis galbana and Nannochloropsis oculata

Abstract

The present work is carried out to evaluate potential applications of aqueous extracts of two microalgae Isochrysis galbana (PEA) and Nannochloropsis oculata (PEB) containing mainly polysaccharides. The monosaccharide composition of microalgal extracts was determined. GC-MS analyses after derivatization show that glucose is the major compound in both microalgae PEA (56.88 %) and PEB (68.23 %). Mannitol (38.8 %) and inositol (20.32 %) are respectively the second major compounds in PEA and PEB. Silylation of monosaccharides allows the determination of sorbitol that attained 3.38 % in PEB. The determination of antioxidant, antimicrobial and cytotoxic properties were also analyzed. Antioxidant activity was evaluated from the DPPH scavenging activity. PEA and PEB show a concentration dependent DPPH·radical scavenging activity. At concentration of 10 mg/mL, both PEA and PEB exhibit an antioxidant activity of 41.45 and 59.07 %, respectively. PEB and PEA are able to inhibit the growth of Gram-negative bacteria, Grampositive bacteria and three Candida species. Cytotoxic activity was evaluated on human HeLa cervical cancer cells. HeLa cell proliferation was totally inhibited after treatment with PEA and PEB (1 mg/mL) and the inhibition was dose dependent (from 0.031 to 1 mg/mL). Their anticholinesterase activity was also investigated against butyrylcholinesterase enzymes. These polysaccharides possess interesting antimicrobial, anticancer and anticholinesterase activities that could represent an additional value for these microalgal products.

Natural Polysaccharides as Preventive and Therapeutic Horizon for Neurodegenerative Diseases

“…In 2017, Hafsa and colleagues reported the extraction of some hydrophilic polysaccharides from microalgae such as Isochrysis galbana and Nannochloropsis oculate, which possessed antimicrobial, anticancer, and anticholinesterase properties [169]. In 2018, Mebrek and colleagues reported that barley-derived beta-glucan, a homopolysaccharide, has moderate antioxidant and enzyme inhibitory activities.…”

Medicinal Prospects of Antioxidants From Algal Sources in Cancer Therapy

“…exhibited significant antioxidant activity revealed through antioxidant assays (Tannin-Spitz et al, 2005;Sun et al, 2014;Amna Kashif et al, 2018). In addition, polysaccharide extract of I. galbana and N. oculata has the antioxidant capacity and antiproliferative activity against HeLa cells (Hafsa et al, 2017). Nostoglycan, a polysaccharide isolated from Nostoc sphaeroides has been reported to give protection from oxidative stress, and also to stop the growth of lung cancer cells as well as to promote apoptosis through activation of the caspase-3 pathway (Li et al, 2018).…”

Bioprospecting of microalgae metabolites against cytokine storm syndrome during COVID-19

“…and Scenedesmus sp . – DPPH radical and hydroxyl radicals [ 86 ], Chlamydomonas reinhardtii [ 87 ] and Rhodella reticulata – superoxide radical ion [ 88 ]; as well as polysaccharides from Isochrysis galbana – superoxide radical ion and hydroxyl radical, H 2 O 2 [ 89 ], Nannochloropsis oculata – DPPH radical [ 90 ] and sulphated polysaccharide from Navicula sp . – DPPH radical, ABTS radical [ 91 ].…”