Seaweeds represent one of the most important marine renewable resources and produce structurally novel secondary metabolites with antibacterial, antialgal, antifungal, antitumoral and antioxidant properties. Therefore, natural products from marine algae appear as a promising alternative valuable source of new compounds for drug development. In particular the application of seaweeds antioxidants in foods, food supplements, nutraceuticals and medicine is recently considered from the perspective of benefits to human health. Moreover seaweeds often produce salt-stable antimicrobial compounds useful in the control of fish or shellfish pathogens in aquaculture where the high-salt conditions might reduce antibiotic efficacy. In this investigation the antimicrobial and antioxidant activity of Cystoseira barbata lipidic extract was assayed The seaweed was collected in the Mar Piccolo of Taranto (Northern Ionian Sea, Italy), washed, dried and powdered. The powdered material was subjected to Soxhlet extraction using choloroform/methanol (2:1 at 55-60 °C for 24 h). Five milligrams of extract were dissolved in ethanol and assayed for antimicrobial activity using the Kirby Bauer method (1966). The antioxidant activity of the extract was measured using two in vitro assays: the TEAC (Trolox Equivalent Antioxidant Capacity) assay based on a single electron transfer (SET) reaction, using ABTS [2-2'-azino-bis (3-ethylbenz-thazoline-6-sulfonic acid)] as chromogen and the ORAC (oxygen radical absorbance capacity) based on a hydrogen transfer mechanism (HAT). The antioxidant activity of the extract measured by TEAC and ORAC assays were respectively equivalent to 225,19±10,99 and 800,67±180,24 ?mol Trolox Equivalent/g extract. These antioxidant values are comparable with those reported in the literature for various high antioxidant fruit and spice extracts. C. barbata lipidic extract showed a bacteriostatic activity against Pseudomonas aerugionsa as well as all the Vibrio species utilized (Vibrio alginolyticus, Vibrio vulnificus, Vibrio cholerae non O-1,). These results are noteworthy considering the resistance against antibiotics developed by bacteria and the need to control fish and shellfish diseases due to vibriosis. The antioxidant activity was also of interest taking into account the potential for protective effects of seaweed against lipid oxidation in food and oxidative stress in target tissue and LDL in vivo.
THE LIPIDIC EXTRACT OF THE SEAWEED CYSTOSEIRA BARBATA (STACKHOUSE) C. AGARD: A POTENTIAL SOURCE OF BIOACTIVE COMPOUNDS
L STABILI;MI ACQUAVIVA;E CECERE;C GERARDI;M NARRACCI;A PETROCELLI;RA CAVALLO
2014
Abstract
Seaweeds represent one of the most important marine renewable resources and produce structurally novel secondary metabolites with antibacterial, antialgal, antifungal, antitumoral and antioxidant properties. Therefore, natural products from marine algae appear as a promising alternative valuable source of new compounds for drug development. In particular the application of seaweeds antioxidants in foods, food supplements, nutraceuticals and medicine is recently considered from the perspective of benefits to human health. Moreover seaweeds often produce salt-stable antimicrobial compounds useful in the control of fish or shellfish pathogens in aquaculture where the high-salt conditions might reduce antibiotic efficacy. In this investigation the antimicrobial and antioxidant activity of Cystoseira barbata lipidic extract was assayed The seaweed was collected in the Mar Piccolo of Taranto (Northern Ionian Sea, Italy), washed, dried and powdered. The powdered material was subjected to Soxhlet extraction using choloroform/methanol (2:1 at 55-60 °C for 24 h). Five milligrams of extract were dissolved in ethanol and assayed for antimicrobial activity using the Kirby Bauer method (1966). The antioxidant activity of the extract was measured using two in vitro assays: the TEAC (Trolox Equivalent Antioxidant Capacity) assay based on a single electron transfer (SET) reaction, using ABTS [2-2'-azino-bis (3-ethylbenz-thazoline-6-sulfonic acid)] as chromogen and the ORAC (oxygen radical absorbance capacity) based on a hydrogen transfer mechanism (HAT). The antioxidant activity of the extract measured by TEAC and ORAC assays were respectively equivalent to 225,19±10,99 and 800,67±180,24 ?mol Trolox Equivalent/g extract. These antioxidant values are comparable with those reported in the literature for various high antioxidant fruit and spice extracts. C. barbata lipidic extract showed a bacteriostatic activity against Pseudomonas aerugionsa as well as all the Vibrio species utilized (Vibrio alginolyticus, Vibrio vulnificus, Vibrio cholerae non O-1,). These results are noteworthy considering the resistance against antibiotics developed by bacteria and the need to control fish and shellfish diseases due to vibriosis. The antioxidant activity was also of interest taking into account the potential for protective effects of seaweed against lipid oxidation in food and oxidative stress in target tissue and LDL in vivo.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
