A 5,7-Dimethoxyflavone/Hydroxypropyl-β-Cyclodextrin Inclusion Complex with Anti-Butyrylcholinesterase Activity

Abstract

This study aimed to improve the water solubility of 5,7-dimethoxyflavone (5,7-DMF) isolated from Kaempferia parviflora by complexation with 2-hydroxypropyl-β-cyclodextrin (HPβ-CD). The phase solubility profile of 5,7-DMF in the presence of HPβ-CD was classified as AL-type and indicated a 1:1 mole ratio. Differential scanning colorimetry, X-ray diffraction, NMR and SEM analyses supported the formation of a 5,7-DMF/HPβ-CD inclusion complex involving the A ring of 5,7-DMF inside the HPβ-CD cavity. This is the first example of CD inclusion with the A ring of non-hydroxyl flavones. The stability and binding constants of the complexes were determined using the phase solubility and UV-vis absorption spectroscopy, respectively. The water solubility of 5,7-DMF was increased 361.8-fold by complexation with HPβ-CD and overcame the precipitation problem observed in aqueous buffers, such as during in vitro anti-butyrylcholinesterase activity assays. The 1:1 mole ratio of the 5,7-DMF/HPβ-CD complex showed a 2.7-fold higher butyrylcholinesterase inhibitory activity (in terms of the IC50 value) compared to the non-complexed compound.

Insights into the formulation properties, biocompatibility, and permeability of poorly water-soluble methoxyflavones with PEG400 and propylene glycol

“…3a). The thermal events occurred between 145 to 155 °C and were comparable to the melting peaks of the methylated flavones (7,24). The melting temperatures of PG and PEG 400 have been reported in the literature as -60 °C and 5.8 °C, respectively (25).…”

Combinations of Piperine with Hydroxypropyl-β-Cyclodextrin as a Multifunctional System

“…An elevation in the solubility of a substance having butyrylcholinesterase inhibition activity may result in an increase in the inhibition of this enzyme, as was already noted in the literature. According to Songngam S. et al’s study, 5,7-dimethoxyflavone isolated from Kaempferia parviflora was combined with HP-β-CD by the freeze-drying method in a 1:1 molar ratio [ 25 ]. The solubility of 5,7-dimethoxyflavone after complexation was 361.8-fold enlarged, and the inhibitory activity of butyrylcholinesterase in vitro (in terms of the IC 50 value) increased 2.7 times.…”

DAF-16 and SKN-1 mediate Anti-aging and Neuroprotective efficacies of “thai ginseng” Kaempferia parviflora Rhizome extract in Caenorhabditis elegans

“…KP also mediated different neurotransmitters by increasing serotonin, norepinephrine and dopamine in the rat hippocampus [10]. DMF exhibited butyrylcholinesterase inhibitory activity [45], whereas another methoxyflavone, 3,5,7,3',4'pentamethoxyflavone exhibited acetylcholinesterase inhibitory activity [46].…”