Antioxidant defence to ammonia stress of characins (Hyphessobrycon eques Steindachner) fed diets supplemented with carotenoids

This study aimed to find out whether dietary carotenoid (CD) supplement could influence the resistance of characins (Hyphessobrycon eques Steindachner) to ammonia stress. Two types of CD and its combination [astaxanthin (AX), β‐carotene (BC), 1 : 1 combination of AX and BC (MX)] at three concentrations (10, 20 and 40 mg kg⁻¹) were used resulting in nine pigmented diets. No differences in growth and survival of the fish among treatments were found after 8‐week rearing. Experimental and control fish were then exposed to 15 mg total ammonia nitrogen L⁻¹ (stress group) and 0.15 mg total ammonia nitrogen L⁻¹ (normal group) for 72 h, and their blood was withdrawn. No mortality resulted under such TAN concentrations. Serum total antioxidant status (TAS), serum antioxidant enzymes [superoxide dismutase (SOD), glutathione peroxidases (GPx)] and serum transaminases [alanine aminotransferase (ALT), aspartate aminotransferase (AST)] were chosen as indices of fish antioxidant capacity or stress resistance. SOD, GPx and AST were affected by the interactions of dietary CD and ammonia stress. The activities of TAS, SOD, GPx and AST increased under the stress. Dietary CD reduced serum SOD, GPx, ALT and AST activities. In conclusion, dietary CD increased the resistance of characins to ammonia stress.     

The mode of action of RH‐1965: a new phenylpyrimidinone bleaching herbicide

RH‐1965 is a new bleaching herbicide which causes newly developing leaf tissue to emerge devoid of photosynthetic pigments. Mode‐of‐action studies revealed that RH‐1965 inhibited the accumulation of both total chlorophyll and β‐carotene. Concomitantly, it induced the accumulation of the β‐carotene precursors, phytoene, phytofluene and, in particular, ξ‐carotene. Inhibition of chlorophyll accumulation by RH‐1965 is attributed to the photo‐oxidative destruction of chlorophyll in the absence of β‐carotene because RH‐1965 blocked chlorophyll accumulation to a greater extent under high light (50–330 µE m⁻² s⁻¹) than under low light (0.8 µE m⁻² s⁻¹) conditions. Radish (Raphanus sativus L) and barnyardgrass (Echinochloa crus‐galli (L) Beauv) were very senstive to RH‐1965. Under high light (330 µE m⁻² s⁻¹), the I₅₀ values for inhibition of chlorophyll accumulation were 0.10 and 0.15 µM , respectively. Wheat (Triticum aestivus L), on the other hand, was much less sensitive to RH‐1965 (I₅₀ = 1.4 µM ). It is concluded that the mode of action of RH‐1965 involves the inhibition of ξ‐carotene desaturation. © 2000 Society of Chemical Industry     

海南省“林-花模式”林下经济发展现状调查及建议

2014年分别在粤东的普宁市、粤西的高州市、粤北的南雄市设点开展自主培育的高胡萝卜素甘薯品种广薯79的种植示范,增产效果显著。通过建立和完善三级繁育体系,定期技术培训、产品回购和向周边地区无偿提供优质种苗等措施,收到很好的示范推广效果和辐射效应。     

Alpha‐tocopherol and β‐carotene in legume–grass mixtures as influenced by wilting,ensiling and type of silage additive

Effects of wilting, ensiling and type of additive on α‐tocopherol and β‐carotene contents in legume–grass mixtures were examined. Swards of birdsfoot trefoil + timothy (Bft + Ti), red clover + timothy (Rc + Ti) and red clover + meadow fescue (Rc + Mf) were harvested as a first regrowth in August 2005. Forage was wilted to a dry‐matter (DM) content of 273 g kg^?1 and ensiled without additive or with an inoculant or acid. Wilting decreased α‐tocopherol concentration by 30% in the Bft + Ti mixture (P = 0·015). Untreated Bft + Ti silage had higher α‐tocopherol content than red clover silages (56·9 vs. 34·2 mg kg^?1 DM; P = 0·015). The α‐tocopherol concentration of Bft + Ti forages increased during ensiling from 41·1 mg kg^?1 DM in wilted herbage to 56·9, 65·2 and 56·8 mg kg^?1 DM in untreated, inoculated and acid‐treated silage respectively (P = 0·015). The inoculant increased α‐tocopherol content in the red clover silages (50·1 vs. 34·2 mg kg^?1 DM; P = 0·015) compared with untreated red clover silages. Red clover mixtures had lower β‐carotene content than Bft + Ti (32·3 vs. 46·2 mg kg^?1 DM; P = 0·016), averaged over treatments. In conclusion, wilting had small effects but the use of bacterial inoculant as an additive and a Bft + Ti mixture increased α‐tocopherol concentration in the silage.     

Effect of supplemental β‐carotene compared to retinyl palmitate on fatty acid profile and expression of mRNA from genes involved in vitamin A metabolism in beef feedlot cattle

To examine the effects of dietary β‐carotene (βC) or retinyl palmitate (RP) on fatty acid (FA) profile and mRNA expression, samples were collected from 24 Angus‐cross calves that were allotted to four treatments consisting of RP supplemented at 2200 IU/kg, and synthetic β‐carotene (SβC) supplemented at one, five or 10 times RP. Longissimus muscle (LM) cis‐9, trans‐11 conjugated linoleic acid was greater in RP compared to SβC1X (P = 0.04). The polyunsaturated:saturated FA increased linearly (P = 0.04) in the LM as dietary SβC increased. Expression of βC oxygenase 2 (βCO2), an enzyme that cleaves β‐carotene, was greater in the LM for SβC1X compared to RP and decreased linearly as SβC increased (P ≤ 0.02). Peroxisome proliferator activated receptor γ (PPARγ) expression in the LM increased in SβC1X compared to RP (P = 0.03); however, PPARγ and retinoic acid X receptor α (RXRα) expression decreased linearly (P = 0.02) in the LM with increasing SβC. Retinoic acid receptor α (RARα) expression tended (P = 0.10) to decrease linearly in the LM with increased SβC. In conclusion, SβC supplementation increased mRNA expression of some lipogenic genes in the LM, but increasing dietary SβC inhibited their expression and tended to increase polyunsaturated FA.     

Comments on the importance of green vegetables

Green, especially leafy, vegetables are widely underesteemed because few horiticultural research institutes publish figures demonstrating that they can give unusually large annual yields of edible dry matter, including protein and carotene (provitamin A). It is also not realised that they supply many communities with as much protein as is supplied by fish, and that more communities used to eat them on that scale. Before leafy vegetables gain proper nutritional attention it will be necessary to convince consumers that they are not merely sources of vitamin C and minerals, or decorative adjuncts to a meal. It will also be necessary to persuade those who compile dietary and production statistics to separate leafy vegetables from other horticultural products which, although they may yield more profit per hectare, are of much less nutritive value.     

Effects of β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin in β‐carotene‐deficient Japanese Black cows

Data from 18 β‐carotene‐deficient Japanese Black cows were collected to clarify the effects of feeding β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin (Ig) in cows. Cows were assigned to control or carrot groups from 3 weeks before the expected calving date to parturition, and supplemental β‐carotene from dry carrots was 138 mg/day in the carrot group. Plasma β‐carotene concentrations in the control and carrot groups at parturition were 95 and 120 μg/dL, and feeding dry carrots slightly improved plasma β‐carotene at parturition. Feeding dry carrots increased colostral IgA concentrations in cows and tended to increase colostral IgG₁, but colostral IgM, IgG₂, β‐carotene and vitamin A were not affected by the treatment. Feeding dry carrots had no effects on plasma IgG₁, IgA and IgM concentrations in cows, but plasma IgG₁ concentrations decreased rapidly from 3 weeks before the expected calving date to parturition. These results indicate that feeding β‐carotene‐enriched dry carrots is effective to enhance colostral IgA and IgG₁ concentrations in β‐carotene‐deficient cows.     

不同品种大果沙棘果实品质研究

在山西省晋中市太谷县试验地,对引进的无刺丰、西伯利亚红晕、壮圆黄、杂交3号和杂交4号5个大果沙棘品种,进行了果实性状及结实情况的研究,结果表明:5个引进大果沙棘的百果鲜重和果柄长度都远大于对照中国沙棘,果实中的维生素C、胡萝卜素和总黄酮含量则远低于对照中国沙棘。     

β‐carotene attenuates lipopolysaccharide‐induced inflammation via inhibition of the NF‐κB,JAK2/STAT3 and JNK/p38 MAPK signaling pathways in macrophages

β‐carotene is one of the most abundant carotenoids, has potential anti‐inflammatory effect, it has been reported that β‐carotene could suppress LPS‐induced inflammatory responses by inhibiting nuclear factor kappa B (NF‐κB) translocation, but the more detailed molecular mechanisms underlying the anti‐inflammatory action of β‐carotene remain to be fully understood. In this study, we investigated the influence of β‐carotene on the activation of JAK2/STAT3, MAPK, and NF‐κB signaling pathway induced by LPS in RAW264.7 cells and peritoneal macrophages. Cells were treated with different concentrations of β‐carotene for 3 hr after LPS treatment for 24 hr. The mRNA expression and the release of IL‐1β, IL‐6, and TNF‐α were evaluated by RT‐PCR and ELISA, and the level of signaling proteins of JAK2/STAT3, MAPK, and NF‐κB signaling pathway were detected by Western blot. The results showed that β‐carotene significantly suppressed (p < 0.05) LPS‐induced release of IL‐1β, IL‐6, and TNF‐α and their mRNA expression. LPS‐induced JAK2/STAT3, IκB/NF‐κB p65, JNK/p38 MAPK signal activation were significantly attenuated (p < 0.05) by β‐carotene in a dose‐dependent manner. In conclusion, β‐carotene could attenuate LPS‐induced inflammation via inhibition of the NF‐κB, JAK2/STAT3, and JNK/p38 MAPK signaling pathways in macrophages.     

早收栽培下高胡萝卜素甘薯的品质特征分析

为探究早收栽培下不同胡萝卜素甘薯类群的食用品质差异,通过早收栽培试验,测定60个品系薯块的胡萝卜素、干物质、熟薯可溶性糖、熟薯还原糖含量及食味,比较不同的胡萝卜素类群及其薯块膨大类型和干物质类型的营养与食味差异,并对薯块营养成分、食味和产量性状的相关性进行分析。结果表明,早收栽培下高胡萝卜素类群的熟薯还原糖含量和食味有一定的优势,在食味指标上黏度优势极显著。高胡萝卜素类群早膨大类型营养与食味明显优于晚膨大类型,且食味与中胡萝卜素类群早膨大类型相当,极显著优于低胡萝卜素类群早膨大类型。高胡萝卜素类群中干物质类型的熟薯糖分和食味与中胡萝卜素类群中干物质类型相当,极显著优于高、中、低胡萝卜素类群的其它干物质类型。橘红肉甘薯的食味主要与熟薯可溶性糖含量和薯块膨大特性有关。因此,在早收栽培下,高胡萝卜素甘薯有较好的食用品质,其早收栽培时,宜选择薯块膨大早、干物质含量中等、熟薯可溶性糖含量超过12%的品种。本研究结果为高胡萝卜素甘薯的鲜食利用及其品种选择提供了依据。