Effects of omega-3, omega-6, and total dietary polyunsaturated fatty acid supplementation in patients with atherosclerotic cardiovascular disease: a systematic review and meta-analysis.

Background: Uncertainty exists about the link between omega-3 fatty acid, omega-6 fatty acid, and total polyunsaturated fatty acid (PUFA) intake and mortality in atherosclerotic cardiovascular disease (ASCVD) patients, and no meta-analyses summarize the relationship between these various types of PUFAs and ASCVD. Methods: Web of Science, PubMed, EBSCO and Cochrane Library up to November 30, 2022 were searched for prospective randomized controlled studies investigating the relationships among omega-3, omega-6, and PUFA intake and mortality and cardiovascular events in ASCVD patients. This study has been registered at PROSPERO (No. CRD42023407566). Results: This meta-analysis included 21 publications from 17 studies involving 40 861 participants published between 1965 and 2022. In ASCVD patients, omega-3 may lower all-cause mortality (RR: 0.90, 95% CI [0.83, 0.98], I2 = 8%), CVD mortality (RR: 0.82, 95% CI [0.73, 0.91], I2 = 34%) and CVD events (RR: 0.90, 95% CI [0.86, 0.93], I2 = 79%). Subgroup analyses showed that EPA or EPA ethyl ester supplementation reduced CVD events, while the mixture of EPA and DHA had no significant impact. Long-chain omega-3 consumption of 1.0-4.0 g per d reduced death risk by 3.5% for each 1 g per d increase. Omega-6 and PUFA had no significant effect on mortality or CVD events, with low-quality evidence and significant heterogeneity. Conclusions: omega-3 intake is associated with a reduced risk of all-cause mortality, CVD mortality, and CVD events in ASCVD patients, while omega-6 or total PUFA intake showed no significant association. Increasing the omega-3 intake by 1 g per d resulted in a 3.5% decrease in the risk of death. These findings support the recommendation of supplements with omega-3 fatty acids for the secondary prevention of ASCVD.

Effect of olive polyphenols on lipid oxidation of high-fat beef during digestion.

Olive oil is one of the most important ingredients in the Mediterranean diet, in which its polyphenols adversely affect dietary lipid oxidation. In this study, the effect of olive oil polyphenols on lipid oxidation of high-fat beef during digestion was determined. Thirty-three phenolic compounds were tentatively identified, and the contents of 3,4-dihydroxyphenylethanol-elenolic acid dialdehyde (3,4-DHPEA-EDA), 3,4-dihydroxyphenylethanol-elenolic acid (3,4-DHPEA-EA), p-hydroxyphenylethanol elenolic acid (p-HPEA-EA) and hydroxytyrosol were higher than those of other compounds. In an in vitro model, the production of lipid oxidation products, including hydroperoxides, malondialdehyde, 4-hydroxy-2-hexenal and 4-hydroxy-2-nominal, were significantly inhibited by olive polyphenol in the gastrointestinal digests. Compared with the other four groups, the inhibition was better when the polyphenol content reached 600 mg GAE/kg. The 3,4-DHPEA-EDA and 3,4-DHPEA-EA played a better antioxidant role in the stomach stage, while hydroxytyrosol showed the more potent antioxidant activity in the intestinal phase. Electron spin resonance technology showed that two main free radicals, including alkyl radical and alkoxy radical, were detected during the high-fat beef digestion, and olive polyphenols could significantly reduce their formation. All these results showed that the lipid oxidation could be significantly inhibited by olive oil with higher polyphenol content, indicating that the consumption of olive oil with abundant levels of polyphenols could reduce lipid oxidation of high-fat meat during digestion.

Effect of Different Solvents on the Extraction of Oil from Peony Seeds (Paeonia suffruticosa Andr.): Oil Yield, Fatty Acids Composition, Minor Components, and Antioxidant Capacity.

Peony seed oil is full of nutrition and exert positive effects on human's health. The influences of seven solvents (isopropanol, acetone, Hx:Iso (n-hexane/isopropanol, 3:2 v/v), Chf:Me (chloroform/methanol, 1:1 v/v), ethyl acetate, n-hexane, and petroleum ether) on the oil yields, lipid composition, minor components and antioxidant capacity of peony seed oil were compared in this study. Results indicated that the highest oil yield (35.63%) was obtained using Hx:Iso, while Chf:Me showed the best extraction efficiency for linolenic acid (43.68%), trilinolenoyl-glycerol (15.00%), and dilinolenoyl-linoleoyl-glycerol (18.01%). For minor components, Chf:Me presented a significant advantage in the extraction of tocopherol (601.49 mg/kg), and the peony seed oil extracted with petroleum ether had the highest sterols (4089.82 mg/kg) and squalene contents (66.26 mg/kg). Although the use of isopropanol led to a lower sterol content, its extracts showed a significant higher polyphenol content (68.88 mg GAE/kg) than other solvents and exhibited the strongest antioxidant capacity. Additionally, correlation analysis revealed that polyphenols were the most important minor component for predicting the antioxidant capacity of peony seed oil. The above information is valuable for manufacturers to select suitable solvents to produce peony seed oil with the required levels of fatty acids and minor components for targeted end-use.

Chemical and volatile characteristics of olive oils extracted from four varieties grown in southwest of China.

The present study was conducted to determine the quality parameters, fatty acid profile, minor compounds (pigments, tocopherols, phenolic compounds, squalene and total sterols) and volatile compounds of olive oils from four common olive cultivars (cv. 'Koroneiki', 'Coratina', 'Frantoio' and 'Arbequina') planted in China. The effect of maturation stage on the characteristics of the oils was also evaluated. All samples were classified as extra virgin according to the standards established by IOC. Statistically significant differences (p < 0.05) were observed in the most analytical indicators of the oils among the cultivar and ripening. Coratina oils contained the highest contents of carotenoids, chlorophylls, tocopherols, phenolic compounds and high level of volatiles, demonstrating their excellent nutritional qualities and pleasant flavors. Whereas, Koroneiki oils contained the highest contents of oleic acid and squalene. Further, high levels of total sterols were found in Frantoio and Arbequina oils. Phenolic compounds and volatiles decreased with increase of ripe degree, which indicated the oils from green olive fruits possess better quality and flavor.

Identification and characterization of N9-methyltransferase involved in converting caffeine into non-stimulatory theacrine in tea.

Caffeine is a major component of xanthine alkaloids and commonly consumed in many popular beverages. Due to its occasional side effects, reduction of caffeine in a natural way is of great importance and economic significance. Recent studies reveal that caffeine can be converted into non-stimulatory theacrine in the rare tea plant Camellia assamica var. kucha (Kucha), which involves oxidation at the C8 and methylation at the N9 positions of caffeine. However, the underlying molecular mechanism remains unclear. Here, we identify the theacrine synthase CkTcS from Kucha, which possesses novel N9-methyltransferase activity using 1,3,7-trimethyluric acid but not caffeine as a substrate, confirming that C8 oxidation takes place prior to N9-methylation. The crystal structure of the CkTcS complex reveals the key residues that are required for the N9-methylation, providing insights into how caffeine N-methyltransferases in tea plants have evolved to catalyze regioselective N-methylation through fine tuning of their active sites. These results may guide the future development of decaffeinated drinks.

Lipiodol deposition in portal vein tumour thrombus predicts treatment outcome in HCC patients after transarterial chemoembolisation.

OBJECTIVE: To study lipiodol deposition in portal vein tumour thrombus (PVTT) in predicting the treatment outcome of hepatocellular carcinoma (HCC) patients after transarterial chemoembolisation (TACE). METHODS: We retrospectively reviewed data from 379 HCC patients with PVTT who underwent TACE as the initial treatment at Sun Yat-Sen University Cancer Center from January 2008 to December 2015. Patients were grouped by positive and negative lipiodol deposition based on the extent of lipiodol deposition in PVTT. The overall survival (OS) and progression-free survival (PFS) were compared between negative and positive lipiodol deposition groups; furthermore, the value of the combinatorial evaluation of tumour responses and lipiodol deposition in PVTT in predicting prognosis was analysed in subgroup patients with stable disease (SD) after TACE. RESULTS: Of the 379 patients, 264 (69.7%) had negative and 115 (30.3%) had positive lipiodol deposition in PVTT after TACE. Multivariate analysis identified positive lipiodol deposition in PVTT as an independent prognostic factor for favourable OS (p = 0.001). The median OS and PFS of negative and positive lipiodol deposition groups were 4.70 vs. 8.97 months (p = 0.001) and 3.1 months vs. 5.8 months (p < 0.001). In subgroup patients, the median OS and PFS of negative and positive lipiodol deposition groups were 4.7 months vs. 10.5 months (p < 0.001) and 3.5 months vs. 7.0 months (p < 0.001), respectively. CONCLUSIONS: The patients with positive lipiodol deposition in PVTT had a longer OS than those with negative lipiodol deposition. Furthermore, the positive lipiodol deposition in PVTT can further differentiate HCC patients with favourable prognosis from SD patients. KEY POINTS: • Lipiodol deposition in PVTT is a prognostic indicator for HCC patients after TACE treatment. • Positive lipiodol deposition in PVTT is associated with a better prognosis.

Hydroclimate changes across the Amazon lowlands over the past 45,000 years.

Reconstructing the history of tropical hydroclimates has been difficult, particularly for the Amazon basin-one of Earth's major centres of deep atmospheric convection. For example, whether the Amazon basin was substantially drier or remained wet during glacial times has been controversial, largely because most study sites have been located on the periphery of the basin, and because interpretations can be complicated by sediment preservation, uncertainties in chronology, and topographical setting. Here we show that rainfall in the basin responds closely to changes in glacial boundary conditions in terms of temperature and atmospheric concentrations of carbon dioxide. Our results are based on a decadally resolved, uranium/thorium-dated, oxygen isotopic record for much of the past 45,000 years, obtained using speleothems from Paraíso Cave in eastern Amazonia; we interpret the record as being broadly related to precipitation. Relative to modern levels, precipitation in the region was about 58% during the Last Glacial Maximum (around 21,000 years ago) and 142% during the mid-Holocene epoch (about 6,000 years ago). We find that, as compared with cave records from the western edge of the lowlands, the Amazon was widely drier during the last glacial period, with much less recycling of water and probably reduced plant transpiration, although the rainforest persisted throughout this time.

The Asian monsoon over the past 640,000 years and ice age terminations.

Oxygen isotope records from Chinese caves characterize changes in both the Asian monsoon and global climate. Here, using our new speleothem data, we extend the Chinese record to cover the full uranium/thorium dating range, that is, the past 640,000 years. The record's length and temporal precision allow us to test the idea that insolation changes caused by the Earth's precession drove the terminations of each of the last seven ice ages as well as the millennia-long intervals of reduced monsoon rainfall associated with each of the terminations. On the basis of our record's timing, the terminations are separated by four or five precession cycles, supporting the idea that the '100,000-year' ice age cycle is an average of discrete numbers of precession cycles. Furthermore, the suborbital component of monsoon rainfall variability exhibits power in both the precession and obliquity bands, and is nearly in anti-phase with summer boreal insolation. These observations indicate that insolation, in part, sets the pace of the occurrence of millennial-scale events, including those associated with terminations and 'unfinished terminations'.

Comparative study of dosimetry between high-dose-rate and permanent prostate implant brachytherapies in patients with prostate adenocarcinoma.

PURPOSE: To compare the dose coverage, conformity, and homogeneity between high-dose-rate (HDR) brachytherapy and permanent prostate implant (PPI) in the treatment of prostate adenocarcinoma. METHODS AND MATERIALS: From January 2003 to August 2004, 54 patients (108 implants) underwent HDR brachytherapy of prostate cancer with iridium-192 stepping source. Of patients who underwent PPI brachytherapy with iodine-125, 72 patients were randomly selected for the purpose of dosimetric comparison. PPI preplan was done based on transrectal ultrasound study, and postplan was done using CT 1 month after implant. Dosimetric parameters of HDR were compared to that of PPI preplan and postplan. RESULTS: HDR brachytherapy had lower D90 (111.5% vs. 120.2%), lower V100 (97.2% vs. 99.6%), lower natural dose ratio (1.03 vs. 1.13), higher conformal index (0.69 vs. 0.62), and higher homogeneity index (0.63 vs. 0.52) than PPI preplan (all p < 0.0001). All the dosimetric parameters of PPI postplan including D90 (86.7%), V100 (82.0%), natural dose ratio (0.92), conformal index (0.53), and homogeneity index (0.42) were inferior to HDR brachytherapy (all p < 0.0001). CONCLUSIONS: HDR brachytherapy of the prostate can provide better dose coverage, conformity, and homogeneity compared to PPI.

Change of vanilloid receptor 1 following neuromodulation in rats with spinal cord injury.

BACKGROUND: Neuromodulation has been used to treat voiding dysfunction caused by spinal cord injury (SCI). However, the underlying mechanism of this technique is not well understood. Recently, vanilloid receptor 1 (VR1) has been recognized as a capsaicin receptor and an agent for noxious stimuli. The purposes of this study were to evaluate whether development of bladder hyperreflexia after SCI involves VR1 upregulation and whether VR1 is involved in the process of neuromodulation. MATERIALS AND METHODS: Sprague-Dawley rats (n = 20) were divided into five groups: sham control (n = 4); 3 days after SCI (n = 4); 7 days after SCI (n = 4); 14 days after SCI (n = 4), and 14 days after SCI with neurostimulation (n = 4). Bilateral electrode wires were implanted into S1 dorsal foramina and electrical stimulation was performed 8 h/day for 2 weeks. Spinal segments of L6, S1, and dorsal root ganglia were removed and cut into sections. The intensity of VR1 staining was evaluated by image analysis. RESULTS: VR1-positive staining was confined to the superficial dorsal horn of the spinal cord. The staining was weak in the sham group (1/luminosity: 0.0050 +/- 0.0006), but the staining intensity was significantly increased in three SCI groups (3 days, 7 days, and 14 days) when compared with that in the sham group (P < 0.05). After neuromodulation, the staining intensity was reduced. CONCLUSIONS: VR1 expression in the spinal cord is up-regulated after SCI. Sacral nerve root stimulation can down-regulate the VR1 expression.