Complexation of curcumin with 2-aminoethyl diphenyl borate and implications for spatiotemporal fluorescence monitoring.

In this study, we successfully determined spatiotemporal distribution of curcumin in mice via simple and fast fluorescence detection of native curcumin and stabilized curcumin. We used 2-aminoethyl diphenyl borate (DPBA) as a stabilizer of curcumin, which binds to curcumin and enhances its aqueous stability. After intravenous injection, curcumin and DPBA-curcumin complexes showed similar fluorescence intensities in the brain, pancreas, lungs, and kidneys at 15min. However, stabilized DPBA-curcumin complexes exhibited much stronger fluorescent signals at metabolically active sites such as liver tissues than native curcumin. After incubation for 1-3h, native curcumin showed significantly rapid reduction of fluorescent signals, compared to DPBA-curcumin complexes, probably due to degradation and reduction. In addition, complicate extraction procedures inhibited precise fluorescent monitoring of unstable curcumin, which result in different biodistribution of curcumin before and after extraction. Direct fluorescent monitoring could allow evaluation of in vivo distribution and fate of curcumin, which could be also applied to diverse natural polyphenols with fluorescent signals.
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