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.

Phytosterols are well-known for their cholesterol-lowering effects, and the structures and forms of phytosterols affect their bioactivity. We aimed to illustrate the phytosterol profiles in common foods and estimate their natural intake in five geographical regions and among different age groups in China. In total, 12 phytosterols in free and esterified forms of 119 foods from five regions across China were examined using gas chromatography-mass spectrometry. Then, the dietary intake of phytosterols was calculated combined with the dietary foods intake data of Chinese people. The total phytosterol content was highest in vegetable oils (150.4-1230.9 mg/100 g), followed by legumes (129.6-275.6 mg/100 g), nuts (18.9-255.2 mg/100 g), and cereals (11.9-93.8 mg/100 g). Vegetables and fruits contained lower contents of total phytosterols. Phytosterols were mainly esterified in most common foods except in nuts. The predominant phytosterols were β-sitosterol, campesterol, and stigmasterol, all of which belonged to plant sterols and 4-desmethylsterols. Total phytosterol intake varied across different regions, ranging between 257.7 and 473.7 mg/standard-person (sp)/day, with the highest intake in Beijing, followed by Hangzhou, Wuhan, Chongqing, and Guangzhou. However, phytosterol proportion was similar across regions, with β-sitosterol accounting for 46.5-50.3% of the natural intake. Phytosterol intake was mainly constituted by plant sterols and 4-desmethylsterols in esterified form (61.9-74.6%). At the age of 2-70 years, phytosterol intake ranged from 154.3 mg/day to 348.0 mg/day in the national scale.

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.

An efficient GC-MS method for determination of sterol oxidation product profiles in edible oils was established by combination with optimized silylation, and validated using the standards of sitosterol oxidation products.