Browsing by Author "Marques, Marta"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Evaluation of the biological potential of Himanthalia elongata (L.) S.F.Gray and Eisenia bicyclis (Kjellman) setchell subcritical water extractsPublication . Gomes, Inês; Rodrigues, Helena; Rodrigues, Carla; Marques, Marta; Paíga, Paula; Paiva, Alexandre; Simões, Pedro; Cruz Fernandes, Virgínia; Vieira, Mónica; Delerue-Matos, Cristina; Soares, Cristina; Grosso, ClaraNeuroprotection is a need that remains unmet in treating chronic neurodegenerative disorders, despite decades of extensive research. To find new neuroprotective compounds, extracts of Himanthalia elongata (L.) S.F.Gray and of Eisenia bicyclis (Kjellman) Setchell were obtained through subcritical water extraction applying a four-step temperature gradient. The fractions obtained were screened against brain enzymes involved in neurodegenerative etiology, namely in Alzheimer’s and Parkinson’s diseases, and against reactive oxygen and nitrogen species, all contributing factors to the progression of neurodegeneration. Results showed no significant enzyme inhibition but strong radical scavenging activities, particularly in the fourth fraction, extracted at the highest temperature (250 °C), highlighting their ability to retard oxidative and nitrosative stresses. At higher temperatures, fractions were composed of phenolic compounds and Maillard reaction products, a combination that contributed to their antioxidant activity and, consequently, their neuroprotective properties. All fractions were evaluated for the presence of iodine, 14 organochlorine and 7 organophosphorus pesticides, and pharmaceuticals used in Alzheimer’s and Parkinson’s diseases (14), psychiatric drugs (8), and metabolites (8). The fractions studied did not present any of the screened contaminants, and only fraction 1 of E. bicyclis should be used with caution due to iodine content.
- Multi-step subcritical water extracts of fucus vesiculosus L. and Codium tomentosum stackhouse: composition, health-benefits and safetyPublication . Soares, Cristina; Paiga, Paula; Marques, Marta; Neto, Tânia; Carvalho, Ana Paula; Paiva, Alexandre; Simões, Pedro; Costa, Leonor; Bernardo, Ana; Fernández, Naiara; Pinto, Edgar; Almeida, Agostinho; Bronze, Maria Rosário; Delerue-Matos, Cristina; Grosso, ClaraMental health and active aging are two of the main concerns in the 21st century. To search for new neuroprotective compounds, extracts of Codium tomentosum Stackhouse and Fucus vesiculosus L. were obtained through multi-step (four step) subcritical water extraction using a temperature gradient. The safety assessment of the extracts was performed by screening pharmaceutical compounds and pesticides by UHPLC-MS/MS, and iodine and arsenic levels by ICP-MS. Although the extracts were free of pharmaceutical compounds and pesticides, the presence of arsenic and high iodine contents were found in the first two extraction steps. Thus, the health-benefits were only evaluated for the fractions obtained in steps 3 and 4 from the extraction process. These fractions were tested against five brain enzymes implicated in Alzheimer’s, Parkinson’s, and major depression etiology as well as against reactive oxygen and nitrogen species, having been observed a strong enzyme inhibition and radical scavenging activities for the step 4 fractions from both seaweed species. Regarding the variation of the chemical composition during the extraction, step 1 fractions were the richest in phenolic compounds. With the increase in temperature, Maillard reaction, caramelization and thermo-oxidation occurred, and the resulting products positively affected the antioxidant capacity and the neuroprotective effects.