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The aim of this review is to provide new findings on health effects of edible flowers since 2015. The antioxidant, anti-inflammatory, anti-cancer, hepatoprotective, neuroprotective, anti-diabetic, anti-osteoporosis, anti-obesity, and anti-hypertensive have been reviewed, and the effective concentrations of flower extracts have been summarized. Among all the health benefits mentioned, anti-osteoporosis, anti-obesity, and anti-hypertensive have rarely been mentioned before 2015. Some health benefits mechanisms of edible flowers were discussed frequently after 2015. Some newly found phytochemicals such as polysaccharides were shown to be beneficial to human health. Species of Rosa, Chrysanthemum, and Osmanthus have been reported to exert different health effects on human. For the toxicity studies, the safe level of flower extracts in cell and animal models were at hundreds of parts per million (ppm) level. In consideration of health promoting effects and toxicities of edible flowers, they could serve as potential natural health products for different health benefits., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Phenolic compounds could be sensitive to digestive conditions, thus a simulated in vitro digestion-dialysis process and cellular assays was used to determine phenolic compounds and antioxidant and antiproliferative potentials of 10 common edible flowers from China and their functional components., Results: Gallic acid, ferulic acid, and rutin were widely present in these flowers, which demonstrated various antioxidant capacities (DPPH, ABTS, FRAP and CAA values) and antiproliferative potentials measured by the MTT method. Rosa rugosa, Paeonia suffruticosa and Osmanthus fragrans exhibited the best antioxidant and antiproliferative potentials against HepG2, A549 and SGC-7901 cell lines, except that Osmanthus fragrans was not the best against SGC-7901 cells. The in vitro digestion-dialysis process decreased the antioxidant potential by 33.95-90.72% and the antiproliferative potential by 13.22-87.15%. Following the in vitro digestion-dialysis process, phenolics were probably responsible for antioxidant (R 2 = 0.794-0.924, P < 0.01) and antiproliferative (R 2 = 0.408-0.623, P < 0.05) potential. Moreover, gallic acid may be responsible for the antioxidant potential of seven flowers rich in edible flowers., Conclusion: The antioxidant and antiproliferative potential of 10 edible flowers revealed a clear decrease after digestion and dialysis along with the reduction of phenolics. Nevertheless, they still had considerable antioxidant and antiproliferative potential, which merited further investigation in in vivo studies. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

This study was aimed at investigating the chemical stability (the thermal, light and pH stability) of phenylethanoid glycosides (PhGs) in Osmanthus fragrans Lour. flowers, identifying the degradation products of acteoside and salidroside (major PhGs in O. fragrans flowers) by UPLC-QTOF-MS and studying the anti-hypoxia activity of PhGs after degradation. The degradation of PhGs followed first-order reaction kinetics, and the rate constant of acteoside (4.3 to 203.4 × 10 -3  day -1 ) was higher than that of salidroside (3.9 to 33.3 × 10 -3  day -1 ) in O. fragrans flowers. Salidroside was mainly hydrolyzed to tyrosol during storage, and the degradation products of acteoside were verbasoside, caffeic acid, isoacteoside, etc. In a model of cobalt chloride (CoCl 2 )-induced hypoxia in PC12 cells, the anti-hypoxia ability of PhGs decreased after degradation, which resulted from the reduction of PhGs contents. Particularly, caffeic acid exhibited stronger anti-hypoxia ability than acteoside and could slightly increase the anti-hypoxia ability of degraded acteoside. The results revealed that high temperature, high pH and light exposure caused PhGs degradation, and thus the anti-hypoxia ability of PhGs reduced.

Introduction: Osmanthus fragrans flowers are used as folk medicine and additives for teas, beverages and foods. The metabolites of O. fragrans flowers from different geographical origins were inconsistent in some extent. Chromatography and mass spectrometry combined with multivariable analysis methods provides an approach for discriminating the origin of O. fragrans flowers., Objective: To discriminate the Osmanthus fragrans var. thunbergii flowers from different origins with the identified metabolites., Methods: GC-MS and UPLC-PDA were conducted to analyse the metabolites in O. fragrans var. thunbergii flowers (in total 150 samples). Principal component analysis (PCA), soft independent modelling of class analogy analysis (SIMCA) and random forest (RF) analysis were applied to group the GC-MS and UPLC-PDA data., Results: GC-MS identified 32 compounds common to all samples while UPLC-PDA/QTOF-MS identified 16 common compounds. PCA of the UPLC-PDA data generated a better clustering than PCA of the GC-MS data. Ten metabolites (six from GC-MS and four from UPLC-PDA) were selected as effective compounds for discrimination by PCA loadings. SIMCA and RF analysis were used to build classification models, and the RF model, based on the four effective compounds (caffeic acid derivative, acteoside, ligustroside and compound 15), yielded better results with the classification rate of 100% in the calibration set and 97.8% in the prediction set., Conclusions: GC-MS and UPLC-PDA combined with multivariable analysis methods can discriminate the origin of Osmanthus fragrans var. thunbergii flowers. Copyright © 2017 John Wiley & Sons, Ltd., (Copyright © 2017 John Wiley & Sons, Ltd.)

The antioxidant synergistic effects of Osmanthus fragrans flowers with green tea were evaluated, and their major antioxidant compounds contributed to the total amount of synergy were determined. The antioxidant compounds in O. fragrans flowers with green tea were identified by LC-MS and quantified by UPLC-PDA. The synergistic antioxidant interactions between O. fragrans flowers with green tea and their antioxidant compounds were tested using the Prieto's model after the simulated digestion. The main antioxidant compounds in O. fragrans flowers were acteoside and salideroside, whereas the main antioxidant compounds in green tea were caffeine, gallic acid, and L-epicatechin. The significant synergistic effect between O. fragrans flowers and green tea was observed and among nearly all of the combinations of their antioxidant compounds. Among the combinations, acteoside and gallic acid contributed most to the antioxidant synergy between O. fragrans flowers and green tea. However, the simulated digestion decreased this antioxidant synergy because it reduced the contents and the antioxidant capacities of their compounds, as well as the antioxidant synergy among the compounds.

This study was aimed to classify the varieties and predict the antioxidant activity of Osmanthus fragrans flowers by UPLC-PDA/QTOF-MS and multivariable analysis. The PLS-DA model successfully classified the four varieties based on both the 21 identified compounds and the effective compounds. For the antioxidant activity prediction, PLS performed well to predict the antioxidant activity of O. fragrans flowers. Furthermore, acteoside, suspensaside A, ligustroside, forsythoside A, phillygenin and caffeic acid were selected as effective compounds by UVE-SPA for prediction. On the basis of effective compounds, PLS, MLR and PCR were applied to establish the calibration models. The UVE-SPA-MLR model was the optimal method to predict the antioxidant activity values with Rp of 0.9200, 0.9010 and 0.8905 for DPPH, ABTS and FRAP assays, respectively. The results revealed that the UPLC-PDA/QTOF-MS combined with chemometrics could be a new method to classify the varieties and predict the antioxidant activity of O. fragrans flowers., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Edible flowers contain numerous phytochemicals which contribute to their health benefits, and consumption of edible flowers has increased significantly in recent years. While many researchers have been conducted, no literature review of the health benefits of common edible flowers and their phytochemicals has been compiled. This review aimed to present the findings of research conducted from 2000 to 2015 on the species, traditional application, phytochemicals, health benefits, and the toxicology of common edible flowers. It was found in 15 species of common edible flowers that four flavonols, three flavones, four flavanols, three anthocyanins, three phenolic acids and their derivatives were common phytochemicals and they contributed to the health benefits such as anti-oxidant, anti-inflammatory, anti-cancer, anti-obesity, and neuroprotective effect. Toxicology studies have been conducted to evaluate the safety of common edible flowers and provide information on their dosages and usages.

Variations of phenylethanoid glycoside profiles and antioxidant activities in Osmanthus fragrans flowers through the digestive tract were evaluated by a simulated digestion model and UPLC/PDA/MS. Major phenylethanoid glycosides and phenolic acids, namely, salidroside, acteoside, isoacteoside, chlorogenic acid, and caffeic acid, were identified in four cultivars of O. fragrans flowers, and the concentration of acteoside was the highest, being up to 71.79 mg/g dry weight. After simulated digestion, total phenylethanoid glycoside contents and antioxidant activities were significantly decreased. Acteoside was identified as decomposing into caffeic acid, whereas salidroside was found to be stable during simulated digestion. According to Pearson's correlation analysis, acteoside contents showed good correlations with antioxidant activities during simulated digestion (R(2) = 0.994, P < 0.01). In conclusion, acteoside was the major contributor to the antioxidant activity of O. fragrans flowers, and salidroside was considered as the major antioxidant compound of O. fragrans flowers in vivo.

Osmanthus fragrans flower extract (OFE) is an organic extract from O. fragrans flower, which exhibits neuroprotective, free radical scavenging, and antioxidant effects. Therefore, the protective effect of OFE and acteoside against aging was studied. An aging ICR mouse model was established by chronically administering d-galactose (250 mg/kg) for 8 weeks. d-galactose induced spatial learning and memory impairments that were successfully inhibited by OFE and acteoside, which could shorten escape latency, improve platform crossing times, and increase zone time. The antioxidant potential of OFE and acteoside in vivo was evaluated by estimating the following: activities of antioxidant enzymes, such as glutathione peroxidase and aging-related enzyme, particularly monoamine oxidase; contents of lipid peroxidation methane dicarboxylic aldehyde, advanced glycation end products, and 8-hydroxy-2'-deoxyguanosine (a DNA damage product); and levels of nuclear factor-erythroid 2-related factor 2. OFE and acteoside also inhibited d-galactose-induced neurological aging by suppressing the increase in glial fibrillary acidic protein and neurotrophin-3. Considering the dose-dependent protective effects of OFE and acteoside, we concluded that OFE, rich in acteoside, was a good source of natural antiaging compounds.

The free and bound phenolic compounds in 10 common Chinese edible flowers were investigated using reversed phase high-performance liquid chromatography. Their antioxidant capacities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging activity, oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), and cellular antioxidant activity (CAA). Free factions were more prominent in phenolic content and antioxidant capacity than bound fractions. Paeonia suffruticosa and Flos lonicerae showed the highest total phenolic content (TPC) 235.5 mg chlorogenic acid equivalents/g of dry weight and total flavonoid content 89.38 mg rutin equivalents/g of dry weight. The major phenolic compounds identified were gallic acid, chlorogenic acid, and rutin. P. suffruticosa had the highest antioxidant capacity in the DPPH, ABTS, and ORAC assays, which were 1028, 2065, 990 μmol Trolox equivalents/g of dry weight, respectively, whereas Rosa chinensis had the highest FRAP value (2645 μmol Fe(2+) equivalents /g of dry weight). The P. suffruticosa soluble phenolics had the highest CAA, with the median effective dose (EC50 ) 26.7 and 153 μmol quercetin equivalents/100 g of dry weight in the phosphate buffered saline (PBS) and no PBS wash protocol, respectively. TPC was strongly correlated with antioxidant capacity (R = 0.8443 to 0.9978, P < 0.01), which indicated that phenolics were the major contributors to the antioxidant activity of the selected edible flowers., (© 2014 Institute of Food Technologists®)