Antioxidant Bioactivity of Extracts from Beach Cast Leaves of Posidonia oceanica (L.) Delile

Abstract

The marine environment is a generous source of biologically active compounds useful for human health. In 50 years, about 25,000 bioactive marine compounds have been identified, with an increase of 5% per year. Peculiar feature of algae and plants is the production of secondary metabolites, such as polyphenols, synthesized as a form of adaptation to environmental stress. Posidonia oceanica is a Mediterranean endemic and dominant seagrass and represents a biologically, ecologically and geologically important marine ecosystem. Within this study, methanolic and ethanolic extracts were generated from fresh and dried Posidonia oceanica leaves, with the aim to employ and valorize the beach cast leaves. The best yield and antioxidant activity (polyphenols content equal to 19.712 ± 0.496 mg GAE/g and DPPH IC50 of 0.090 µg/µL.) were recorded in 70% ethanol extracts (Gd-E4) obtained from leaves dried for two days at 60 °C and ground four times. HPLC analyses revealed the presence of polyphenols compounds (the most abundant of which was chicoric acid) with antioxidant and beneficial properties. Bioactive properties of the Gd-E4 extracts were evaluated in vitro using fibroblast cells line (HS-68), subjected to UV induced oxidative stress. Pre-treatment of cells with Gd-E4 extracts led to significant protection against oxidative stress and mortality associated with UV exposure, thus highlighting the beneficial properties of antioxidants compounds produced by these marine plants against photo damage, free radicals and associated negative cellular effects. Beach cast leaves selection, processing and extraction procedures, and the in vitro assay results suggested the potentiality of a sustainable approach for the biotechnological exploitation of this resource and could serve a model for other marine resources.

In Vitro Cytotoxic Effect of Aqueous Extracts from Leaves and Rhizomes of the Seagrass Posidonia oceanica (L.) Delile on HepG2 Liver Cancer Cells: Focus on Autophagy and Apoptosis

“…Regarding the number and nature of the polyphenolic compounds found in the two different biologically active Posidonia matrices, they were mostly in agreement with the literature data [ 8 , 12 , 67 ]. The differences could be correlated with the extraction method followed, as well as the quantities extracted by volume/weight.…”

“…Early reports identified the antimicrobial activity of rhizome and grass extracts [ 2 , 3 ] and also demonstrated the dose-dependent glucose lowering and vasoprotective effects of the preparations from P. oceanica in a diabetic rat model [ 4 ]. In addition, the antioxidant, antiaging, antiinflammatory and antiglycation activities of the leaf extracts have been recently acknowledged [ 5 , 6 , 7 , 8 ]. A limited number of papers have also examined the anticancer potential of P. oceanica extracts.…”

Antioxidant Activity, Inhibition of Intestinal Cancer Cell Growth and Polyphenolic Compounds of the Seagrass Posidonia oceanica’s Extracts from Living Plants and Beach Casts

“…However, the activities of bioactive substances derived from marine macrophytes, especially that of the seagrasses, have not been thoroughly investigated, due to their great biodiversity [ 13 ]. Recently, research interest has turned towards the characterization of the P. oceanica bioactive components [ 14 , 15 , 16 , 17 , 18 , 19 ]. Additionally, P. oceanica leaf dead mass is used for the manufacture of glassware, roof insulation, animal feed, fertilizers, energy production [ 14 , 15 , 18 ] and even the detection of new bioactive compounds after cultivation of their associated microbial community [ 19 ].…”

“…The antioxidant activity has been studied in the living leaves of different seagrass species such as Posidonia oceanica , Zostera marina , Thalassia testudinum , T. hemprichii , Thalassodendron ciliatum , Halodule pinifolia and Spyringodium filiforme [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. However, the relevant studies are too limited for the seagrass’ dead mass [ 16 , 17 , 41 ]. Extracts from seagrasses have displayed a high ability to neutralize free radicals, as they are a rich source of secondary metabolites, such as the phenolic compounds p -coumaric, caffeic, gallic, chicoric, trans -ferulic, caftaric, protocatechuic, p- hydroxybenzoic, vanillic acid, gentisic acid and quercetin [ 42 , 43 , 44 , 45 , 46 ].…”

New Bioactive Peptides from the Mediterranean Seagrass Posidonia oceanica (L.) Delile and Their Impact on Antimicrobial Activity and Apoptosis of Human Cancer Cells

“…The seagrass Posidonia oceanica (L.) Delile is an endemic plant in the Mediterranean Sea, and plays an important ecological role in marine ecosystem [ 24 , 25 ]. Few reported studies have illustrated the pharmacological properties of this seagrass, which is an important emergent depository of bioactive substances with antioxidant [ 26 , 27 , 28 ], antitumoral [ 29 , 30 , 31 ], antibacterial, and antifungal actions that are mostly related to their secondary metabolites (alkaloids, flavanoids, phenols, tannins, saponins, phlobatannins, sterols, proteins, reducing sugar polysaccharides and resins, etc.) [ 32 , 33 , 34 ].…”