Preclinical study on camellia sinensis extract-loaded nanophytosomes for enhancement of memory-boosting activity: optimization by central composite design

The purpose of the present study was to enhance the memory-boosting activity of the standardized hydroalcoholic Camellia sinensis extract (CSE) by the formation of nanophytosomes with Leciva S70 phospholipid. The central composite design was used to optimize the solvent evaporation method for the formulation of C. sinesis phytosomes (CSP).

The optimized formulation had a mean particle size of 212.3 nm ± 0.39, PDI of 0.238 ± 0.0197, and zeta potential of −42.02 ± 0.995 mV. C. sinensis phytosome formation was confirmed by analytical techniques. The aqueous solubility of the developed CSP was 95.92 ± 0.31, which is 7.34 times greater than that of pure CSE (13.07 ± 0.19). CSP was found more effective than either pure CSE (26.42 ± 0.4654%) or the physical mixture (32.15 ± 0.4596%) in releasing the CSE from the formulation (72.16 ± 0.5248%). Acute toxicity study corroborated the safety of CSP in rats. CSP demonstrated a significant (p < 0.05) reduction in escape and transferred latency on both days (15th and 16th) as compared to CSE, indicating the improvement of the memory-boosting activity. Furthermore, CSP-treated rats significantly improved acetylcholine (Ach) levels and brain tissue concentration compared with CSE. Moreover, the phytosomal formulation of CSP exhibited its rationality with an improvement of bioavailability by 3.21 folds compared with pure CSE.

The presence of phospholipids in the CSP formulation and the formation of smaller particles may aid in crossing the blood–brain barrier, increasing brain tissue concentration and bioavailability. This, in turn, leads to an increase in memory-boosting activity.