Validation of a High-Performance Liquid Chromatography with Photodiode Array Detection Method for the Separation and Quantification of Antioxidant and Skin Anti-Aging Flavonoids from Nelumbo nucifera Gaertn. Stamen Extract

Abstract

Nelumbo nucifera Gaertn., or the so-called sacred lotus, is a useful aquatic plant in the Nelumbonaceae family that has long been used to prepare teas, traditional medicines as well as foods. Many studies reported on the phytochemicals and biological activities of its leaves and seeds. However, to date, only few studies were conducted on its stamen, which is the most important ingredient for herbal medicines, teas and other phytopharmaceutical products. Thus, this present study focuses on the following: (1) the application of high-performance liquid chromatography with photodiode array detection for a validated separation and quantification of flavonoids from stamen; (2) the Nelumbo nucifera stamen’s in vitro and in cellulo antioxidant activities; as well as (3) its potential regarding the inhibition of skin aging enzymes for cosmetic applications. The optimal separation of the main flavonoids from the stamen ethanolic extract was effectively achieved using a core-shell column. The results indicated that stamen ethanolic extract has higher concentration of in vitro and in cellulo antioxidant flavonoids than other floral components. Stamen ethanolic extract showed the highest protective effect against reactive oxygen/nitrogen species formation, as confirmed by cellular antioxidant assay using a yeast model. The evaluation of potential skin anti-aging action showed that the stamen extract has higher potential to inhibit tyrosinase and collagenase compared with its whole flower. These current findings are the first report to suggest the possibility to employ N. nucifera stamen ethanolic extract as a tyrosinase and collagenase inhibitor in cosmetic applications, as well as the utility of the current separation method.

Medicinal foods and plants with antiaging properties: A review of in vitro and in vivo studies

“…(Ersoy et al., 2019). Stamen extract of Nelumbo nucifera displayed better inhibition of both tyrosinase and collagenase than the whole flower, whereas the results are similar for elastase and hyaluronidase (Tungmunnithum et al., 2022). Aquilegia pubiflora leaf extracts (Jan et al., 2021) and Isodon rugosus cultures (Abbasi et al., 2019) also inhibited the enzymes at varying degrees.…”

Flavonoid Profiles and Antioxidant Potential of Monochoria angustifolia (G. X. Wang) Boonkerd & Tungmunnithum, a New Species from the Genus Monochoria C. Presl

“…Validation was performed as described previously by Tungmunnithum et al [23] and according to the Association of Analytical Communities (AOAC) standards, so as to ensure the accuracy and the reproducibility of quantification [24].…”

Flavonoid Profiles and Antioxidant Potential of Monochoria angustifolia (G. X. Wang) Boonkerd & Tungmunnithum, a New Species from the Genus Monochoria C. Presl

“…Validation was performed as described previously by Tungmunnithum et al [23] and according to the Association of Analytical Communities (AOAC) standards to assure accuracy and reproducibility in quantification [24].…”