Human ectopic olfactory receptors and their food originated ligands: a review.

Ectopic olfactory receptors (EORs) are expressed in non-nasal tissues of human body. They belong to the G-protein coupled receptor (GPCR) superfamily. EORs may not be capable of differentiating odorants as nasal olfactory receptors (ORs), but still can be triggered by odorants and are involved in different biological processes such as anti-inflammation, energy metabolism, apoptosis etc. Consumption of strong flavored foods like celery, oranges, onions, and spices, is a good aid to attenuate inflammation and boost our immune system. During the digestion of these foods in human digestive system and the metabolization by gut microbiota, the odorants closely interacting with EORs, may play important roles in various bio-functions like serotonin release, appetite regulation etc., and ultimately impact health and diseases. Thus, EORs could be a potential target linking the ligands from food and their bioactivities. There have been related studies in different research fields of medicine and physiology, but still no systematic food oriented review. Our review portrays that EORs could be a potential target for functional food development. In this review, we summarized the EORs found in human tissues, their impacts on health and disease, ligands interacting with EORs exerting specific biological effects, and the mechanisms involved.

Inhibition of Three Diabetes-Related Enzymes by Procyanidins from Lotus (Nelumbo nucifera Gaertn.) Seedpods.

The inhibitory effects of procyanidins from lotus (Nelumbo nucifera Gaertn.) seedpods on the activities of α-amylase, α-glucosidase and protein tyrosine phosphatase 1B (PTP1B), were studied and compared with those of (+)-catechin, (-)-epicatechin, epigallocatechin gallate (EGCG), procyanidin dimer B2 and trimer C1. The results showed that Lotus procyanidin extract (LPE) significantly inhibited α-amylase, α-glucosidase and PTP1B with IC50 values of 5.5, 1.0, and 0.33 µg/mL, respectively. The inhibition increased with the degree of polymerization and the existence of galloyl or gallocatechin units. Kinetic analysis showed that LPE inhibited α-glucosidase activity in a mixed competitive and noncompetitive mode. Fluorescence quenching revealed that α-glucosidase interacted with LPE or EGCG in an apparent static mode, or the model of "sphere of action". The apparent static (K) and bimolecular (kq) constants were 4375 M-1 and 4.375 × 1011 M-1 s-1, respectively, for LPE and 1195 M-1 and 1.195 × 1011 M-1 s-1, respectively, for EGCG. Molecular docking analysis provided further information on the interactions of (+)-catechin, (-)-epicatechin, EGCG, B2 and C1 with α-glucosidase. It is hypothesized that LPE may bind to multiple sites of the enzyme through hydrogen bonding and hydrophobic interactions, leading to conformational changes in the enzyme and thus inhibiting its activity. These findings first elucidate the inhibitory effect of LPE on diabetes-related enzymes and highlight the usefulness of LPE as a dietary supplement for the prophylaxis of diabetes.

6-Shogaol from ginger shows anti-tumor effect in cervical carcinoma via PI3K/Akt/mTOR pathway.

PURPOSE: 6-Shogaol, an active phenolic compound from ginger (Zingiber officinale), can inhibit the growth of a variety of human cancer cells. Nevertheless, its underlying molecular mechanisms in cervical cancer remain unclear. In this study, we systematically examine the inhibitory effect of 6-shogaol on cervical cancer in vitro and in vivo. METHODS: Cell proliferation was assessed by CCK8 assay and colony formation assay in HeLa and SiHa cells. We analyzed cell cycle and apoptosis through flow cytometry. GFP-LC3 puncta and transmission electron microscopy were used to observe autophagic bodies. Wound-healing assay and transwell assay were used for evaluating the migration of cells. Western blot was applied to detect protein expression levels. RESULTS: 6-Shogaol could suppress cell proliferation and migration, cause cell cycle arrest in the G2/M phase in HeLa and SiHa cells. Moreover, 6-shogaol triggered the apoptosis process through the mitochondrial pathway by downregulating the expression levels of p-PI3K, p-Akt and p-mTOR. Further research indicated that the induction of apoptosis by 6-shogaol was remarkably decreased after the treatment of ROS scavenger and PI3K agonist. Additionally, 6-shogaol increased the number of LC3-positive puncta and autophagic bodies per cell in both HeLa and SiHa cells. Pretreatment of cells with Bafilomycin A1, an autophagy inhibitor, accelerated 6-shogaol mediated cell apoptosis, suggesting that induction of autophagy by 6-shogaol is suppressive to apoptosis. Furthermore, in vivo data revealed that 6-shogaol significantly inhibited tumor growth and cell proliferation in tumor tissues. CONCLUSION: These findings suggested that 6-shogaol could be developed as a functional food ingredient, which is potentially used as therapeutic agents for patients with cervical cancer.

Predicting the Pro-Inflammatory Effects of Oxidized Methyl Oleate Based on the Volatile Compounds.

The negative impact of lipid peroxidation on health is intimately tied to its oxidation products. In this study, methyl oleate was oxidized at 180℃ for 0, 2, 4, 8 and 12 h respectively. The free radicals and volatile components generated during the oxidation process were determined using electron spin resonance and headspace solid-phase microextraction (HS-SPME)-GC-MS. The pro-inflammatory effects of oxidized methyl oleate were evaluated in RAW264.7 cells. Then partial least-squares regression (PLSR) models were established for predicting the 3 pro-inflammatory genes expression based on the volatile components. The results revealed that the alkoxy radical content increased rapidly during oxidation from 4 h to 8 h, and the rate of oxidation of methyl oleate dropped after 8 h. A total of 27 volatile oxidation compounds were detected by HS-SPME-GC-MS. The content of most compounds, including aldehydes, esters, and acids, exhibited a pattern of initial increase and then decrease as the oxidation time increased. Similarly, the proinflammatory effects of oxidized methyl oleate peaked after 8 h of oxidation. The PLSR quantitative prediction models showed that the coefficient of determination (R2P) between the predicted and measured values of the 3 inflammatory gene expressions were 0.915, 0.946 and 0.951 respectively. The established PLSR model predicts the pro-inflammatory effects of oxidized methyl oleate well and provides a theoretical foundation for quick evaluation of the pro-inflammatory effects of oxidized lipids.

Quantitative Modeling of the Degradation of Pesticide Residues in Wheat Flour Supply Chain.

Pesticide residues in grain products are a major issue due to their comprehensive and long-term impact on human health, and quantitative modeling on the degradation of pesticide residues facilitate the prediction of pesticide residue level with time during storage. Herein, we tried to study the effect of temperature and relative humidity on the degradation profiles of five pesticides (carbendazim, bensulfuron methyl, triazophos, chlorpyrifos, and carbosulfan) in wheat and flour and establish quantitative models for prediction purpose. Positive samples were prepared by spraying the corresponding pesticide standards of certain concentrations. Then, these positive samples were stored at different combinations of temperatures (20 °C, 30 °C, 40 °C, 50 °C) and relative humidity (50%, 60%, 70%, 80%). Samples were collected at specific time points, ground, and the pesticide residues were extracted and purified by using QuEChERS method, and then quantified by using UPLC-MS/MS. Quantitative model of pesticide residues was constructed using Minitab 17 software. Results showed that high temperature and high relative humidity accelerate the degradation of the five pesticide residues, and their degradation profiles and half-lives over temperature and relative humidity varied among pesticides. The quantitative model for pesticide degradation in the whole process from wheat to flour was constructed, with R2 above 0.817 for wheat and 0.796 for flour, respectively. The quantitative model allows the prediction of the pesticide residual level in the process from wheat to flour.

Fabrication and characterization of natural polyphenol and ZnO nanoparticles loaded protein-based biopolymer multifunction electrospun nanofiber films, and application in fruit preservation.

To extend the shelf life of sweet cherries (Prunus avium L.) and considering the environmental problems caused by traditional packaging materials, novel Zein/Gelatin-proanthocyanidins-zinc oxide nanoparticles (ZE/GE-PC-ZnO) and Zein/Gelatin-gallic acid-zinc oxide nanoparticles (ZE/GE-GA-ZnO) protein-based composite nanofiber films were prepared by electrospinning. According to the results, ZE/GE-PC-ZnO and ZE/GE-GA-ZnO films' contact angles were higher than those of Zein/Gelatin film by 28.91% and 21.27%, and their antioxidant activities were 5 and 9 times higher, respectively. Moreover, ZE/GE-PC-ZnO film showed good inhibitory activity against B. cinerea. On the eleventh day of the cherry packaging test, compared to unwrapped cherries, the losses of weight and firmness of wrapped fruit were reduced by more than 20% and 60%, respectively. Respiration time was delayed by 5 days, and the peak of ethylene release was decreased by nearly half. In conclusion, these two nanofiber films were viable packaging materials that fulfilled global strategies for green development.

Effects of food emulsifiers on high fat-diet-induced obesity, intestinal inflammation, changes in bile acid profile, and liver dysfunction.

Obesity has become one of the most prevalent health concerns of our time. A long-term high-fat diet is closely related to obesity. Food emulsifiers are incorporated into high-fat foods to enhance the texture and stability. Whether food emulsifiers exacerbate obesity and metabolic disorders induced by a high-fat diet remains unclear. This study aimed to investigate the effects of polysorbate-80 (P80) and polyglycerol polyricinoleate (PGPR) on lipid metabolism, bile acid profile, and gut microbiota in normal and high-fat-diet-induced obesity in mice. The results of this study showed that P80 and PGPR had little effect on body weight but significantly increased epididymal-fat weight, total energy intake, and blood lipid levels. P80 and PGPR stimulated colon inflammation and improved the expression of inflammatory factors in the colon and liver significantly. P80 and PGPR changed the bile acid profile. However, P80 and PGPR did not aggravate inflammation, obesity and alter bile acid profile by altering the composition of the gut microbiota. The results of this study provide an experimental reference for the rational use of food additives and the adjustment of dietary structure, which are important and have application value.

Pingyin Rose Essential Oil Restores Intestinal Barrier Integrity in DSS-induced Mice Colitis Model.

Rosa rugosa cv. Plena is a 'drug homologous food' in China with a long history. Pingyin rose essential oil (PREO) is a mixture of compounds extracted from blooming R. rugosa cv. Plena. With its elegant smell and excellent effects on oxidative stress and inflammation alleviation, PREO is wildly used in the food industry as a popular additive. We aimed to decipher if the PREO could alleviate and restore dextran sodium sulfate (DSS)-induced barrier integrity damages. The results showed that a 7-day PREO (15 µL/kg) treatment alleviated the colitis symptoms by improving disease activity index (DAI) scores through weight loss, occult blood, and colon shortening. The expression of tight junction proteins and the enzyme activities of superoxide dismutases (SOD), and catalase (CAT) increased while nitric oxide (NO), malondialdehyde (MDA), and myeloperoxidase (MPO) production decreased in PREO-treated C57BL6 female mice. PREO treatment inhibited the expression of pro-inflammatory cytokines tumor necrosis factor (TNF-α), interleukin (IL)-1ß, and IL-6. Further, PREO modulated the composition of the gut microbiota and Spearman's correlation analysis revealed a positive effect. The transcriptome analysis and western blot results indicated that PREO might ameliorate intestinal barrier dysfunction in this study via the TLR4-NF-kB signaling pathway. We hypothesized that PREO has preventive potential against gut disorders and could serve as a functional food additive.

Antibacterial activity of oregano essential oils against Streptococcus mutans in vitro and analysis of active components.

BACKGROUND: Streptococcus mutans (S. mutans) is considered the most relevant bacteria during the transition of the non-pathogenic commensal oral microbial community to plaque biofilms that promote the development of dental caries. Oregano (Origanum vulgare L.), is a universally natural flavoring and its essential oil has been demonstrated to have good antibacterial effects. However, the specific antibacterial mechanism of oregano essential oil (OEO) against S. mutans is still not completely understood. METHODS: In this work, the composition of two different OEOs was determined by GC‒MS. Disk-diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined to assess their antimicrobial effect on S. mutans. The inhibition of acid production, hydrophobicity, biofilm formation and real-time PCR for gtfB/C/D, spaP, gbpB, vicR, relA and brpA mRNA expression by S. mutans were assessed to preliminarily investigate the mechanisms of action. Molecular docking was performed to simulate the interactions with the virulence proteins and active constituents. MTT test using immortalized human keratinocytes cells was also performed to investigate cytotoxicity. RESULTS: Compared with the positive drug Penicillin /streptomycin 100X (DIZ: 34.13 ± 0.85 mm, MIC: 0.78125 µL/mL, MBC: 6.25 µL/mL), the essential oils of Origanum vulgare L. (DIZ: 80 mm, MIC: 0.625µL/mL, MBC:2.5µL/mL) and Origanum heracleoticum L. (DIZ: 39.67 ± 0.81 mm, MIC: 0.625µL/mL, MBC: 1.25µL/mL) could also exhibit similar effects to inhibit the acid production and reduce the hydrophobicity and biofilm formation of S. mutans at 1/2-1MIC concentration. And gene expression of gtfB/C/D, spaP, gbpB, vicR and relA were found to be downregulated. Due to the composition of essential oils from different sources being highly variable, through effective network pharmacology analysis, we found that OEOs contained many effective compounds, like carvacrol and its biosynthetic precursors γ-terpinene and p-cymene, which may directly target several virulence proteins of S. mutans. Besides, no toxic effect was instigated by OEOs at 0.1 µL/mL in the immortalized human keratinocytes cells. CONCLUSION: The integrated analysis in the present study suggested that OEO might be a potential antibacterial agent for the prevention of dental caries.

Extraction, bioactive function and application of wheat germ protein/peptides: A review.

The aging population and high incidence of age-related diseases are major global societal issues. Consuming bioactive substances as part of our diet is increasingly recognized as essential for ensuring a healthy life for older adults. Wheat germ protein has a reasonable peptide structure and amino acid ratio but has not been fully utilized and exploited, resulting in wasted wheat germ resources. This review summarizes reformational extraction methods of wheat germ protein/peptides (WGPs), of which different methods can be selected to obtain various WGPs. Interestingly, except for some bioactive activities found earlier, WGPs display potential anti-aging activity, with possible mechanisms including antioxidant, immunomodulatory and intestinal flora regulation. However, there are missing in vitro and in vivo bioactivity assessments of WGPs. WGPs possess physicochemical properties of good foamability, emulsification and water retention and are used as raw materials or additives to improve food quality. Based on the above, further studies designing methods to isolate particular types of WGPs, determining their nutritional and bioactive mechanisms and verifying their activity in vivo in humans are crucial for using WGPs to improve human health.

Six Spain Thymus essential oils composition analysis and their in vitro and in silico study against Streptococcus mutans.

BACKGROUND: Streptococcus mutans is a well-known oral pathogen that plays a critical role in the development of dental caries. Many studies have been directed to discover the chemical compounds present in natural products to inhibit the growth and biofilm formation activity of S. mutans. Thymus essential oils exhibit good inhibition on the growth and pathogenesis of S. mutans. However, details about the active compounds in Thymus essential oil and the inhibition mechanism still remain unclear. The aim of this study was to investigate the antimicrobial activity of 6 Thymus species (Three samples of Thymus vulgaris, two samples of Thymus zygis, and one sample of Thymus satureioides essential oils) on S. mutans, to identify the potential active components, and to reveal the underlying mechanism. METHODS: The composition of Thymus essential oils was analyzed by gas chromatography-mass spectrometry. And its antibacterial effect was evaluated based on the bacterial growth, acid production, biofilm formation and genetic expression of virulence factors by S. mutans. Potential active components of the Thymus essential oil were identified using molecular docking and correlation analysis. RESULTS: GC-MS analysis showed that the major components in the 6 Spain Thymus essential oils were linalool, α-terpineol, p-cymene, thymol and carvacrol. MIC and MBC analysis showed that 3 Thymus essential oils showed very sensitive antimicrobial activity, and were chosen for further analysis. The 3 Thymus essential oil exhibited a significant inhibitory effect on acid production, adherence and biofilm formation of S. mutans and the expression of virulence genes, such as brpA, gbpB, gtfB, gtfC, gtfD, vicR, spaP and relA. Correlation analysis showed that phenolic components, such as carvacrol and thymol, were positively related to DIZ value, which suggests that they are the potential antimicrobial components. Molecular docking between the Thymus essential oil components and virulence proteins also found that carvacrol and thymol exhibited strong binding affinity with functional domains of virulence genes. CONCLUSIONS: Thymus essential oil showed significant inhibition against the growth and pathogenesis of S. mutans depending on their composition and concentration. And phenolic compounds, such as carvacrol and thymol, are the major active components. Thymus essential oil could be used in oral healthcare products as a potential anti-caries ingredient.

Transcriptomic and physiological analysis reveals the possible mechanism of ultrasound inhibiting strawberry (Fragaria × ananassa Duch.) postharvest softening.

Ultrasound effectively inhibited strawberry softening but the mechanism was not clear. In this study, physical data including firmness, soluble pectin (SP) contents, pectin esterase (PE), polygalacturonase (PG) activity and transcriptome sequencing data were analyzed to explore the mechanism of strawberry response to ultrasonic treatment. After 24 days storage, the firmness reduction rate and soluble contents (SP) increased rate of the strawberry treated with ultrasound (25 kHz, 0.15 W/cm2) for 3 min decreased 41.70 and 63.12% compared with the control, respectively. While the PG and PE enzyme activities of ultrasound-treated strawberries were significantly lower than control after storage for 18 days. A total of 1,905 diferentially expressed genes (DEGs) were identified between ultrasound-treated and control, with 714 genes upregulated and 1,254 genes downregulated, including 56 genes in reactive oxygen species (ROS), auxin (AUX), ethylene (ETH) and jasmonic acid (JA) signaling pathways. At 0 h, 15 genes including LOX, JMT, ARP, SKP, SAUR, IAA, ARF, and LAX were significantly upregulated compared with the control group, which means reactive oxygen specie, auxin, ethylene and jasmonic acid-mediated signaling pathway respond to ultrasound immediately. ERF109, ERF110, and ACS1_2_6 downregulated before 2 days storage indicated ethylene signaling pathway was inhibited, while after 2 days, 9 genes including ERF027, ERF109, and ERF110 were significantly upregulated indicating that the response of the ethylene signaling pathway was lagging. Therefore, in strawberry ultrasound enhanced ROS scavenging and activated JA biosynthesis, which acts as a signal for delaying the activation of ET signaling pathway, thus suppressing the activity of pectin-degrading enzymes PE and PG, and ultimately inhibiting postharvest softening.

In vitro and in silico analysis of 'Taikong blue' lavender essential oil in LPS-induced HaCaT cells and RAW264.7 murine macrophages.

BACKGROUND: 'Taikong blue' lavender, a space-bred cultivar of Lavandula angustifolia, is one of the main lavender essential oil production crops in Xinjiang Province, China. Several cases of local usage indicated that 'Taikong blue' lavender essential oil (TLEO) had excellent anti-inflammatory and antioxidant properties for skin problems. However, to date, substantial data on these functions are lacking. In this study, we aimed to investigate the composition and bioactivities of TLEO and the potential underlying mechanisms through LPS-induced inflammatory models of HaCaT and RAW264.7 cells. METHODS: The composition of TLEO was determined by GC‒MS. To study the anti-inflammatory and antioxidative properties of TLEO, we induced HaCaT and RAW264.7 cells by LPS. TLEO (0.001%-0.1%, v/v) was used to treat inflamed cells with dexamethasone (DEX, 10 µg/mL) as the standard drug. A variety of tests were carried out, including biochemical assays, ELISA, RT‒PCR, and western blotting. Docking of components was performed to predict potential ligands. RESULTS: The GC‒MS analysis revealed that 53 compounds (> 0.01%) represented 99.76% of the TLEO, and the majority of them were esters. TLEO not only reduced the levels of oxidative stress indicators (NO, ROS, MDA, and iNOS at the mRNA and protein levels) but also protected the SOD and CAT activities. According to the RT‒PCR, ELISA, and Western blot results, TLEO decreased inflammation by inhibiting the expression of TNF-α, IL-1ß, IL-6, and key proteins (IκBα, NF-кB p65, p50, JNK, and p38 MAPK) in MAPK-NF-кB signaling. Molecular docking results showed that all of the components (> 1% in TLEO) were potent candidate ligands for further research. CONCLUSION: The theoretical evidence for TLEO in this study supported its use in skin care as a functional ingredient for cosmetics and pharmaceutics.

α-Cyperone inhibits the proliferation of human cervical cancer HeLa cells via ROS-mediated PI3K/Akt/mTOR signaling pathway.

Cervical cancer is the fourth leading killer of female cancer patients worldwide. Each year more than half a million women are diagnosed with cervical cancer and the disease results in over 300, 000 deaths. α-Cyperone is known as the principal active ingredient in the Cyperus rotundus (Family: Cyperaceae). However, the effects of α-Cyperone on cancers, especially on cervical cancer, are yet to be explored. In the present study, the underlying mechanism of the anti-tumor activity of α-Cyperone against HeLa cells was investigated. The results showed that α-Cyperone inhibited proliferation and induced apoptosis in HeLa cells. Mechanistically, α-Cyperone promoted HeLa cells apoptosis via a mitochondrial apoptotic pathway, which was proved by increased level of intracellular reactive oxygen species (ROS) and upregulated expression of cytochrome c, cleaved caspase-3, PARP, and Bax. Further RNA-sequencing revealed α-Cyperone inhibited the activation of PI3K/Akt/mTOR signaling pathway in HeLa cells, which confirmed by PI3K inhibitor and agonist. The PI3K inhibitor (LY294002) synergized with α-Cyperone in arresting the growth of HeLa cells, whereas the PI3K agonist (IGF-1) abrogated such an effect. Interestingly, the expression of PD-L1 was attenuated by both α-Cyperone and LY294002, while the supplement of IGF-1 rescued the low expression of PD-L1. In conclusion, our results reveal that the inhibitory effect of α-Cyperone on HeLa cell growth is triggered via the ROS-mediated PI3K/Akt/mTOR signaling pathway and closely related to a decline in the PD-L1 expression.

Oenothein B inhibits human non-small cell lung cancer A549 cell proliferation by ROS-mediated PI3K/Akt/NF-κB signaling pathway.

Oenothein B has a wide range of biological activities. The present study probed into the underlying mechanism on how Oenothein B inhibits the proliferation of a lung cancer line A549. Our results showed that Oenothein B effectively inhibited the proliferation of A549 cells by inducing apoptosis and arresting cells at G1 stage. Furthermore, Oenothein B not only increased the level of intracellular reactive oxygen species (ROS), but also induced the upregulation of intracellular apoptotic triggers (cleavage caspase-3, PARP, cytochrome c level in the cytosol, Bax). Moreover, ROS inhibitor (N-acetyl-L-cystein, NAC) and PI3K agonist (Insulin-like growth factor 1, IGF-1) could resist cell proliferation inhibition induced by Oenothein B, respectively. ROS inhibitor significantly abrogated the activation of caspase 3/7 and 9 in the presence of Oenothein B. Additionally, suppression of p-PI3K and p-Akt, p-NF-κB by Oenothein B could be compensated by treatment with ROS inhibitor. To summarize, these results demonstrated that Oenothein B was able to prevent cell proliferation probably via ROS-mediated PI3K/Akt/NF-κB signaling pathway.

Rapid preparation of procyanidins B2 and C1 from Granny Smith apples by using low pressure column chromatography and identification of their oligomeric procyanidins.

Research in the field of procyanidins is always hindered by the lack of procyanidin standards, and the preparation of procyanidins, especially in large scale, remains difficult and time-consuming. Commercial sources of procyanidin standards are scarce. In this study, a rapid preparation method of procyanidins by using low-pressure column chromatography was developed. Procyanidins in Granny Smith apples were extracted with boiled water and purified on an ADS-17 macroporous resin column to obtain a Granny Smith apple procyanidin extract (GSE). GSE was fractionated according to its degree of polymerization on a Toyopearl TSK HW-40s column. Procyanidins B2 (epicatechin-(4beta-8)-epicatechin) and C1 (epicatechin-(4beta-8)-epicatechin-(4beta-8)-epicatechin) were prepared without HPLC separation. Oligomeric procyanidins from Granny Smith apples were also identified by liquid chromatography-electrospray ionization-mass spectrometry.

Evaluation of antioxidant activity and preventing DNA damage effect of pomegranate extracts by chemiluminescence method.

The antioxidant activities of three parts (peel, juice, and seed) and extracts of three pomegranate varieties in China were investigated by using a chemiluminescence (CL) method in vitro. The scavenging ability of pomegranate extracts (PEs) on superoxide anion, hydroxide radical, and hydrogen peroxide was determined by the pyrogallol-luminol system, the CuSO4-Phen-Vc-H2O2 system, and the luminol-H2O2 system, respectively. DNA damage preventing the effect of PE was determined by the CuSO4-Phen-Vc-H2O2-DNA CL system. The results showed that the peel extract of red pomegranate had the best effect on the scavenging ability of superoxide anion because its IC50 value (4.01 +/- 0.09 microg/mL) was the lowest in all PEs. The seed extract of white pomegranate could scavenge hydroxide radical most effectively of the nine extracts (the IC50 value was 1.69 +/- 0.03 microg/mL). The peel extract of white pomegranate had the best scavenging ability on hydrogen peroxide, which had the lowest IC50 value (0.032 +/- 0.003 microg/mL) in the nine extracts. The seed extract of white pomegranate (the IC50 value was 3.67 +/- 0.03 microg/mL) was the most powerful on the DNA damage-preventing effect in all of the PEs. Also, the statistical analysis indicated that there were significant differences (at P < 0.05) among the extracts of the different varieties and parts in each system.

Characterization of oligomeric procyanidins and identification of quercetin glucuronide from lotus ( Nelumbo nucifera Gaertn.) seedpod.

Procyanidins are a class of polyphenols in the plant kingdom. Lotus ( Nelumbo nucifera Gaertn.) seedpods, the inedible part of lotus and a byproduct during the production of lotus seeds, were found to be a new source rich in procyanidins. Detailed information about oligomeric procyanidins in lotus seedpods remains unknown. In this study, lotus seedpods were extracted using 60% aqueous methanol and characterized with phloroglucinolysis and liquid chromatography (mass spectrometry with an electrospray ionization source). The results indicate that the oligomeric and polymeric fraction had a mean degree of polymerization of 3.2 and 15.4, respectively, and consisted of (+)-catechin (m/z 289), gallocatechin or epigallocatechin (m/z 305), quercetin glycoside (m/z 463), quercetin glucuronide (m/z 477), procyanidin dimers (m/z 577.1), proanthocyanidin dimer gallate (m/z 593.3), prodelphinidin dimers (m/z 609.1), procyanidin trimers (m/z 865.1), etc. Quercetin glucuronide was further purified using flash chromatography and identified as quercetin-3-O-ß-glucuronide by determining its exact mass using ion-trap time-of-flight mass spectrometry and ¹H and ¹³C nuclear magnetic resonance, ¹H-detected heteronuclear single-quantum coherence, and ¹H-detected heteronuclear multiple-bond correlation analyses.