Untargeted metabolomics and in vitro functional analysis unravel the intraspecific bioactive potential of flowers from underexplored Camellia japonica cultivars facing their industrial application
The Camellia genus comprises a vast array of underexplored medicinal plants that merit a systematic valorization
to exploit their potential as natural sources of phytochemicals with associated health-promoting properties. In
this work, flower extracts from eight poorly characterized Camellia japonica L. cultivars were subjected to
polyphenol profiling through untargeted metabolomics combined with in vitro functional analysis. Anthocyanins,
mostly represented by cyanidin 3-O-glycosides, flavones, and flavonols, were found as the major constituents of
C. japonica flowers, together with hydroxycinnamic acids, tyrosols, alkylphenols, and stilbenes, which were
detected for the first time in this species. The application of multivariate statistics revealed a flower colordependent
fingerprint of C. japonica cultivars, featuring anthocyanins and other flavonoids as metabolite
markers associated with color-flowered cultivars with respect to white-flowered ones. The accumulation of anthocyanins,
especially reported in ‘Eugenia de Montijo’ flowers, was highly correlated with the cytotoxic and
anti-inflammatory properties of the derived extracts, including AGS, Caco-2, and MCF7 cancer cell lines.
Moreover, the flavones accumulation reported in ‘Carolyn Tuttle’ extracts was also associated with high rates of
free-radical scavenging activity, as well as a potent cytotoxicity against the Caco-2 cell line. In general,
C. japonica anthocyanin-enriched flower extracts were revealed as promising candidates for the industrial production
of polyphenols with associated biological activities of high interest for critical sectors in the food,
pharmaceutical, and cosmetic industries.
The research leading to these results was supported by MICINN
supporting the Ramón y Cajal grant for M.A.-P. (RYC-2017–22891) and
the Juan de la Cierva Formación grant for T.-O. (FJC2019–042549-I).
The authors acknowledge Xunta de Galicia for funding the post-doctoral
grant of L. C. (ED481B-2021/152) and the program EXCELENCIAED431F
2020/12, which supported the work by F.C. The authors are
also grateful to the Foundation for Science and Technology (FCT,
Portugal) for financial support through national funds FCT/MCTES
(PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and
SusTEC (LA/P/0007/2020), and national funding by FCT, P.I., through
the institutional scientific employment program contract for L.-B. and R.
C.-C. The work by P.G.-P. was financed by the Spanish Ministry of
Universities under the application 33.50.460A.752 and by the European
Union NextGenerationEU/PRTR through a Margarita Salas contract by
the Universidade de Vigo.
