Composition and Bioactivity of Essential Oil from Citrus grandis (L.) Osbeck 'Mato Peiyu' Leaf.

'Mato Peiyu' pomelo (Citrus grandis (L.) Osbeck 'Mato Peiyu') leaves from pruning are currently an agricultural waste. The aim of this study was to isolate essential oils from these leaves through steam distillation (SD) and solvent-free microwave extraction (SFME) and to evaluate their applicability to skin care by analyzing their antimicrobial, antioxidant (diphenyl-1-picrylhydrazyl scavenging assay, ß-carotene/linoleic acid assay, and nitric oxide scavenging assay), anti-inflammatory (5-lipoxygenase inhibition assay), and antityrosinase activities. The gas chromatography-mass spectrometry results indicated that the main components of 'Mato Peiyu' leaf essential oils were citronellal and citronellol, with a total percentage of 50.71% and 59.82% for SD and SFME, respectively. The highest bioactivity among all assays was obtained for 5-lipoxygenase inhibition, with an IC50 value of 0.034% (v/v). The MIC90 of the antimicrobial activity of essential oils against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans ranged from 0.086% to 0.121% (v/v). Citronellal and citronellol were the main contributors, accounting for at least 54.58% of the essential oil's bioactivity. This paper is the first to report the compositions and bioactivities of 'Mato Peiyu' leaf essential oil, and the results imply that the pomelo leaf essential oil may be applied in skin care.

Hydroxycinnamic acid bound arabinoxylans from millet brans-structural features and antioxidant activity.

Hydroxycinnamic acid bound arabinoxylans (HCA-AXs) were extracted from brans of five Indian millet varieties and response surface methodology was used to optimize the extraction conditions. The optimal condition to obtain highest yield of millet HCA-AXs was determined as follows: time 61min, temperature 66°C, ratio of solvent to sample 12ml/g. Linkage analysis indicated that hydroxycinnamic acid bound arabinoxylan from kodo millet (KM-HCA-AX) contained comparatively low branched arabinoxylan consisting of 14.6% mono-substituted, 1.2% di-substituted and 41.2% un-substituted Xylp residues. The HPLC analysis of millet HCA-AXs showed significant variation in the content of three major bound hydroxycinnamic acids (caffeic, p-coumaric and ferulic acid). The antioxidant activity of millet HCA-AXs were evaluated using three in vitro assay methods (DPPH, FRAP and ß-carotene linoleate emulsion assays) which suggested both phenolic acid composition and structural characteristics of arabinoxylans could be correlated to their antioxidant potential, the detailed structural analysis revealed that low substituted KM-HCA-AX exhibited relatively higher antioxidant activity compared to other medium and highly substituted HCA-AXs from finger (FM), proso (PM), barnyard (BM) and foxtail (FOXM) millet.

Systematic comparison of nutraceuticals and antioxidant potential of cultivated, in vitro cultured and commercial Melissa officinalis samples.

Melissa officinalis (lemon balm) infusions are used worldwide for digestive, analgesic and other pharmaceutical applications. Herein, the nutraceuticals production and antioxidant potential in garden cultivated, in vitro cultured and two commercial samples (bags and granulated) of lemon balm was compared. The profile of in vitro cultured lemon balm is closer of garden cultivated sample than of both commercial samples (bag or granulate). It presented the highest levels of proteins and ash, and the lowest energetic value. The most favorable n6/n3 ration, as also the highest PUFA (mostly α-linolenic acid), tocopherols (including α-, γ- and δ-isoforms) and ascorbic acid contents were also observed in this sample. Nevertheless, it was the commercial bag lemon balm that gave the highest antioxidant activity and the highest levels of phenolics and flavonoids. As far as we kwon, this is the first comparison of nutraceuticals and antioxidant potential of cultivated, in vitro cultured and commercial lemon balm samples. Moreover, it proved that in vitro culture might be used to stimulate vitamins production.

Interactions of beta-carotene and flavonoids on the secretion of pro-inflammatory mediators in an in vitro system.

Chronic inflammation, a process linked to increased oxidative stress, may induce many diseases. Whether beta-carotene prevents inflammation is unclear. Using phorbol-12-myristate-13-acetate (PMA)-stimulated HL-60 cells, we investigated the effects of 2 or 20 microM beta-carotene on the inflammatory reaction of monocyte/macrophage-like cells and the modulation of 20 microM quercetin or naringenin, two flavonoids, of the effects of beta-carotene. The effects of quercetin and naringenin were compared with that of alpha-tocopherol, a well-known antioxidant. The stimulated HL-60 cells were also co-incubated with A549 cells to investigate the DNA-damaging ability of the stimulated monocyte/macrophage-like cells on target cells. Our results showed that preincubation with 20 microM beta-carotene significantly enhanced the release of two pro-inflammatory mediators, interleukin-8 and tumor necrosis factor-alpha, in PMA-stimulated HL-60 cells and slightly increased the DNA-damaging ability of these cells. By contrast, 2 microM beta-carotene had an inhibitory effect on the inflammatory reaction in PMA-stimulated cells. The higher dose of beta-carotene also exerted pro-inflammatory effects in lipopolysaccharide-stimulated RAW264.7 cells. Furthermore, quercetin, naringenin, and alpha-tocopherol partly suppressed the pro-inflammatory effects of 20 microM beta-carotene on PMA-stimulated HL-60 cells, and the suppressing effects of quercetin and naringenin were better than or similar to those of alpha-tocopherol. Quercetin also additively or synergistically enhanced the inhibitory effects of 2 microM beta-carotene on the secretion of pro-inflammatory mediators and the DNA-damaging ability of PMA-stimulated HL-60 cells. The mechanisms underlying the effect of the flavonoids were associated with their antioxidant activity and inhibition of the production of pro-inflammatory cytokines. Our results urge consideration of the safety of beta-carotene supplementation concerning effects on inflammation and suggest that the interaction between beta-carotene and quercetin or naringenin may alter the effects of beta-carotene on the secretion of pro-inflammatory mediators.

Antioxidant activity and bioactive compounds of ten Portuguese regional and commercial almond cultivars.

The antioxidant properties of different almond cultivars (cv.), either regional (Casanova, Duro Italiano, Molar, Orelha de Mula and Pegarinhos cv.) or commercial (Ferraduel, Ferranhês, Ferrastar and Guara cv.) were evaluated through several chemical and biochemical assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of beta-carotene bleaching, inhibition of oxidative hemolysis in erythrocytes, induced by 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH), and inhibition of thiobarbituric acid reactive substances (TBARS) formation in brain cells, all used as models for the lipid peroxidation damage in biomembranes. The EC50 values were calculated for all the methods in order to evaluate the antioxidant efficiency of each almond cultivar. Bioactive compounds such as phenols and flavonoids were also obtained and correlated to antioxidant activity. The results obtained were quite heterogeneous, revealing significant differences among the cultivars assayed. Duro Italiano cv. revealed better antioxidant properties, presenting lower EC50 values in all assays, and the highest antioxidants contents. The protective effect of this cultivar on erythrocyte biomembrane hemolysis was maintained during 4h.

Oral vitamin E supplementation on oxidative stress, vitamin and antioxidant status in intensely exercised horses.

REASONS FOR PERFORMING STUDY: Vitamin E is the most commonly supplemented antioxidant in horses; however, previous research is not conclusive as to the recommended level for exercising horses. OBJECTIVE: To evaluate the effects of 3 levels of vitamin E supplementation on oxidative stress and vitamin/antioxidant status in intensely exercised horses to determine the optimal level of vitamin E supplementation. METHODS: Twelve unfit Standardbreds were divided into 3 groups, supplemented orally with 0 (CON), 5000 (MOD), or 10,000 (HI) iu/day of DL-alpha-tocopheryl acetate. The 3 x 3 Latin square design consisted of three 4 week supplementation periods with 4 week wash out periods between. After each period, horses underwent a treadmill interval exercise test. Blood samples were collected and heart rate (HR) measured before, during and after exercise. Data were analysed using ANOVA with repeated measures in SAS. RESULTS: The CON group had lower HR throughout the test compared to the MOD and HI groups (P<0.05). There was an increase in plasma retinol (RET), beta-carotene (BC), red blood cell total glutathione and glutathione peroxidase with exercise (P<0.05), but all groups returned to baseline after 24 h. Plasma alpha-tocopherol (TOC) increased from baseline with exercise (P<0.0001) in all groups; treatment differences were observed at 24 h (P<0.05). The HI and CON groups had lower BC compared to the MOD group (P = 0.05). CONCLUSIONS: Horses supplemented with vitamin E, at nearly 10-times the 1989 NRC recommended level, did not experience lower oxidative stress compared to control horses. Additionally, lower plasma BC levels observed in the HI group, which may indicate that vitamin E has an inhibitory effect on BC metabolism. POTENTIAL RELEVANCE: Supplementation above control levels is not more beneficial to oxidative stress and antioxidant status in intensely exercising horses; indeed, levels 10 times in excess may be detrimental to BC and should be avoided.

Omega-3 fatty acids enhance tumor necrosis factor-alpha levels in heart transplant recipients.

BACKGROUND: Proinflammatory cytokines may contribute to clinical complications in heart transplant (HTx) recipients. Previous studies have shown immunomodulating effects of omega-3 fatty acids, but the results are somewhat conflicting. In this study, we examined plasma levels of tumor necrosis factor alpha (TNF-alpha), interleukin (IL) 10, and their relations to antioxidant vitamins in 45 HTx recipients before and after treatment with omega-3 fatty acids or placebo. METHODS: The patients were long-time survivors of heart transplantation, randomized in a double-blind fashion to receive omega-3 fatty acids (3.4 g/day) or placebo for 1 year. Plasma levels of cytokines were measured by enzyme immunoassays and vitamin A, vitamin E, and beta-carotene by high-performance liquid chromatography. RESULTS: In the omega-3, but not in the placebo group, there was a rise in the proinflammatory cytokine TNF-alpha (P<0.05), a decrease in the anti-inflammatory cytokine IL-10 (P=0.07), and a rise in TNF/IL-10 ratio (P<0.05) after 12 months, suggesting a proinflammatory net effect. In the omega-3 group, the increase in TNF-alpha was associated with an increase in eicosapentaenoic acid in plasma (r=0.58, P<0.02). During omega-3 fatty-acid treatment, but not during placebo, there was a decrease in vitamin E (P<0.05) and beta-carotene (P<0.05) levels, and the decrease in vitamin E was inversely correlated with the increase in TNF-alpha (r= -0.56, P<0.01). The rise in TNF-alpha levels during omega-3 fatty acids treatment was most pronounced in those patients with transplant coronary artery disease (P<0.04). CONCLUSION: Our data suggest that omega-3 fatty acids in HTx recipients may change the balance between proinflammatory and anti-inflammatory cytokines in an inflammatory direction, possibly related to prooxidative effects of these fatty acids.

Inhibitory activity of vitamin E and alpha-naphthoflavone on beta-carotene-enhanced transformation of BALB/c 3T3 cells by benzo(a)pyrene and cigarette-smoke condensate.

We previously found that beta-carotene (betaCT) can act as a co-carcinogenic agent enhancing the cell transforming activity of powerful carcinogens such as benzo(a)pyrene (B(a)P) and cigarette-smoke condensate (TAR) in an in vitro medium-term ( approximately 8 weeks) experimental model utilizing BALB/c 3T3 cells (Mutat. Res. 440 (1999) 83-90). Here, we investigated whether vitamin E (VitE) and alpha-naphthoflavone (alphaNF) are able to affect the co-carcinogenic activity of betaCT in terms of inhibiting B(a)P and TAR cell transforming potential. The following experimental schedules were performed: (i) cultures treated for 72 h with chemicals in various experimental combinations (acute treatment); (ii) cultures grown in presence of tester agents for the whole period of the assay (chronic treatment) to more closely mimic human exposure. While the co-carcinogenic potential of betaCT was confirmed on both B(a)P and TAR, the latter being ineffective by itself, we found in repeated experiments that the presence of VitE or alphaNF significantly reduced the betaCT's enhancing effect in the formation of transformation foci by B(a)P and TAR. The mechanism of the inhibition could be explained by the known ability of alphaNF to inhibit cytochrome P450-linked B(a)P-bioactivating monooxygenases, while VitE may contrast the prooxidant activity of betaCT (e.g., oxygen radicals overgeneration). While highlighting the importance of increasing knowledge of the role of single provitamins, vitamins and micronutrients, our findings also underline the potential advantages of combining several dietary supplements in in vitro preventive investigations.