Characterization of Codium tomentosum phytosomes and their neuroprotective potential

Due to the increase in life expectancy, promoting active aging is a crucial challenge for the XXI century. Therefore, searching for new neuroprotective drugs is urgent, and marine macroalgae are considered excellent sources of structurally diverse bioactive molecules with recognized pharmaceutical and biomedical potential. Aiming to contribute to finding new neuroprotective drugs, a multi-step subcritical water extraction (SWE) process was applied to the green macroalga Codium tomentosum using a gradient of temperatures (from room temperature to 250 ^⸰C). Four fractions were obtained and F4 (obtained in the range of 190-250 ^⸰C), rich in phenolic compounds and Maillard reaction products, was the most active against oxidative stress and enzymes linked to neurodegeneration and major depression. Phytosomes were prepared with F4 as an encapsulation strategy to entrap this bioactive fraction for future applications. A Box-behnken design with three independent variables [A – time (1- 4 h), B – temperature (25- 60 ^⸰C), and C – ratio F4:phosphatidylcholine (1:1-1:4)] was applied. The optimal condition retrieved from the model to obtain the highest % of encapsulation (61%) was: A – 1h, B – 59 ^⸰C, and C – 1:1. These phytosomes were further modified with DSPE-PEG(20000)-maleimide and ApoE and characterized by dynamic light scattering (DLS), UV spectrophotometry, octanol-water partition coefficient (Kow), differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR). Results of the FTIR and DSC studies confirmed the phyto-phospholipid complex formation, and DLS analysis revealed that phytosomes had a mean particle size of 245.76±49.00 nm and a polydispersity of 0.26±0.06. Moreover, phytosomes had a ʎmax at 280 nm and a Kow = 0.382.

Future work will include the development of a neuroprotective functional food product suitable for elderly, incorporating F4 or F4-based phytosomes.

Acknowledgements:

This work was supported by projects REQUIMTE/LAQV—UIDB/50006/2020 and UIDP/50006/2020, financed by FCT/MCTES, through national funds, and by project POCI-01-0145-FEDER-030240—PTDC/OCE-ETA/30240/2017—SilverBrain-From sea to brain: Green neuroprotective extracts for nanoencapsulation and functional food production, financed by FEDER and FCT.