Evaluation of the Biological Potential of Himanthalia elongata (L.) S.F.Gray and Eisenia bicyclis (Kjellman) Setchell Subcritical Water Extracts

Abstract

Neuroprotection 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), psychatric 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.

Blueberry Pruning Wastes: From an Undervalued Agricultural Residue to a Safe and Valuable Source of Antioxidant Compounds for the Food Industry

“…For the FRAP assay, calibration was performed with AA (linearity range: 10-100 mg/L, R 2 > 0.9989), and the results were expressed in mg of AA equivalents per g of dw (mg AAE/g dw). The ABTS protocol was performed as previously described by Pinto et al [27]. The calibration curve (linearity range: 5-50 mg/L, R 2 > 0.9994) was obtained using AA, and the results were expressed as mg AAE/g dw.…”

Exploring the Antiradical Potential of Species from Lamiaceae Family: Implications for Functional Food Development in the Context of Neurodegenerative and Neuropsychiatric Diseases

“…A spectrophotometric assay based on the Folin-Ciocalteu reagent [12] was employed to determine the TPC values of each extract, and calibration curves were performed using gallic acid. The formation of the blue complex was monitored at 760 nm in a microplate reader (Synergy HT, Biotek Instruments, Winooski, VT, USA).…”

“…The antiradical capacity was assessed against two radicals, namely, DPPH • and ABTS •+ , according to well-established procedures [12]. Absorbances were monitored in a microplate reader (Synergy HT, Biotek Instruments, Winooski, VT, USA) at 517 and 734 nm, respectively.…”

A Critical Comparison of the Advanced Extraction Techniques Applied to Obtain Health-Promoting Compounds from Seaweeds

“…Concerning step 4 fraction obtained at higher temperatures (190-250 • C), Maillard reaction, caramelization and thermo-oxidation occurred, and products such as melanoidins are responsible for the antioxidant capacity and the neuroprotective effects. The same SWE conditions described previously [34] (four steps, different temperatures) were applied by Gomes et al [75] to H. elongata and E. bicyclis. These authors observed that, although no significant enzyme inhibition was detected, fractions 3 and 4 presented the highest biological activities, namely DPPH • , ABTS •+ , • NO, and O 2…”