Anti-Alzheimer's Activity of Polyphenolic Stilbene-Rich Acetone Fraction of the Oil-Removed Seeds of Passiflora edulis: in Vivo and in Silico Studies

The stilbene-rich acetone fraction in high yield (6.6 %, PEAS) of Passiflora edulis Sims was prepared and evaluated for neuroprotective activity in murine Alzheimer's disease model induced by aluminum chloride and D-galactose. The phytochemical and HPLC-DAD-MS analysis of the polyphenolic stilbene-rich acetone fraction showed that it contained different stilbenes including trans-piceatannol, scirpusins A-B and cassigarol E. The total phenolic content (TPC) of PEAS was 413.87±1.71 mg GAE eqv/g. The neuroprotective activity of PEAS is typically presented in the Morris water maze-reference Spatial Memory test, where the Alzheimer's mice treated at 100 mg/kg (Alz-ED1) and 200 mg/kg (Alz-ED2) spent less than 47 % and 66 % of the time, respectively, than the Alzheimer's model mice (Alz). Two simple stilbenes, trans-piceatannol and trans-resveratrol, showed selectively inhibitory activity in silico against acetylcholinesterase (AChE). Two stilbene dimers, cassigarol E and scirpusin A, exhibited low nanomolar inhibitory potential against AChE and butyrylcholinesterase (BChE), significantly lower than those of the positive control, donepezil and tacrine. These findings suggest that the stilbenes from P. edulis seeds, particularly the stilbene dimers, warrant further investigation as potential neuroprotective candidates in the prevention of cognitive deficits associated with Alzheimer's disease.

Optimization of canthaxanthin extraction from fermented biomass of Paracoccus carotinifacuens VTP20181 bacteria strain isolated in Vietnam

Introduction. The bacterium strain Paracoccus carotinifaciens VTP20181 isolated in Vietnam produces canthaxanthin, a carotenoid widely used in the food and pharmaceutical industries. The aim of this work was to determine optimal parameters for canthaxanthin extraction from fermented biomass of P. carotinifaciens VTP20181. Study objects and methods. First, a series of single factor investigations were carried out in regard to maximal carotenoid content in the biomass extract obtained by using ultrasonic waves. Four parameters of the extraction process, such as extraction temperature, solvent/material ratio, extraction time, and ultrasonic output power, were studied. The obtained results were then optimized by using Response Surface Methodology (RSM) and Box-Behnken experimental design. Results and discussion. The optimal technological parameters of the extraction process included extraction temperature of 35°C, solvent/material ratio of 9.5:1 (v/w), extraction time of 90 min, and ultrasonic output power of 145 W. Under optimal conditions, canthaxanthin and total carotenoid contents were determined as 14.95 ± 0.12 and 18.21 ± 0.11 mg/g respectively, which were compatible with theoretical calculations ‒ 15.074 and 18.263 mg/g, respectively. Conclusion. Current results confirmed that the strain of halophilic P. carotinifaciens VTP20181 is a potential source for canthaxanthin biosynthesis.