Effects of Cultivation Month and Genetic Background on Phenolic Content of <i>Citrus tachibana</i> Peel

Abstract

Species of the Citrus genus are known as rich sources of phenolic compounds. Peels of Citrus tachibana and Citrus unshiu are used in herbal formulations, sometimes in similar ways. In this study, we examined the effects of plant maturity and genetic background on the total phenolic contents and quantities of specific flavonoids in C. tachibana peel. In addition, we compared these values in C. tachibana and C. unshiu peels. The total phenolic contents and the contents of nobiletin, tangeretin, and hesperidin were higher in the extracts of the immature peel than in those of the mature peels of C. tachibana; moreover, the quantities of these compounds were also influenced by the genetic background of C. tachibana. In the extracts of C. unshiu peel, the contents of total phenolics, nobiletin, and tangeretin were lower than those of C. tachibana peel. However, the hesperidin content was higher in extracts of C. unshiu peel than those of C. tachibana peel. This study evaluated the phenolic and flavonoid contents of C. tachibana and C. unshiu in an effort to provide new insights into herbal medicines for further study and utilization.

Evaluation of dynamic changes in the bioactive components in Citri Reticulatae Pericarpium (Citrus reticulata ‘Chachi’) under different harvesting and drying conditions

“…Some studies have reported that the content of phenolic acids, which exhibit strong antioxidant activity, decreases depending on the ripeness of fruits. 20,21 The results of this study are consistent with those of previous literature, where it is illustrated that the antioxidant capacity of CRCP might be reduced with delayed harvesting. Besides, Ledesma-Escobar et al have reported that phenolic acid and flavonoids reached maximum concentration at week 5 and 12, respectively, and then decreased significantly during growth, which might relate to the concentration change of phenylalanine, a precursor in the phenol pathway.…”

The Anti-Aging Potential of Extracts from Chaenomeles sinensis

“…It has been reported that neutrophil elastase is indirectly involved in collagen and elastin degradation through MMP-1 and MMP-2 activation as well as by direct degradation [5]. It has also been reported that exposure to UV and particulate matter 2.5 (PM 2.5) induces excessive ROS generation, leading to DNA damage in normal cells and increased MMP (collagenase) levels, which can promote skin aging [15][16][17][18]. It is considered that supplements that prevent elastase and collagenase activity, as well as superoxide generation, are useful as ingredients in cosmetics that slow down skin aging.…”

“…Assay for SOD-like activity was performed as described previously [15]. The reaction mixture contained the extracts, 0.2 M Tris-HCl buffer (pH 7.8), 0.1 mM EDTA-2Na, 0.1 mM xanthine, 0.05 mM nitro blue tetrazolium, and 0.05 U xanthine oxidase.…”

“…The collagenase inhibition assay was performed, as described previously [15]. The reaction mixture contained the extracts or Fr.1−6 samples, 0.025 M Tris-HCl buffer (pH 7.5), 0.25 mg/mL FITC-labeled collagen, and 0.05 U collagenase.…”

“…The total phenolic content was determined in accordance with our previous study [15], which uses the Folin-Ciocalteu reagent. The reaction mixture contained the Fr.1-6 samples, 0.5 N Folin-Ciocalteu reagent, and 0.29 M sodium carbonate.…”