Hypotriacylglycerolemic and Antiobesity Properties of a New Fermented Tea Product Obtained by Tea-Rolling Processing of Third-Crop Green Tea (Camellia sinensis) Leaves and Loquat (Eriobotrya japonica) Leaves

We manufactured a new fermented tea by tea-rolling processing of third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) leaves. The mixed fermented tea extract inhibited pancreatic lipase activity in vitro, and effectively suppressed postprandial hypertriacylglycerolemia in rats. Rats fed a diet containing 1% freeze-dried fermented tea extract for 4 weeks had a significantly lower liver triacylglycerol concentration and white adipose tissue weight than those fed the control diet lacking fermented tea extract. The activity of fatty acid synthase in hepatic cytosol markedly decreased in the fermented tea extract group as compared to the control group. The serum and liver triacylglycerol- and body fat-lowering effects of the mixed fermented tea extract were strong relative to the level of dietary supplementation. These results suggest that the new fermented tea product exhibited hypotriacylglycerolemic and antiobesity properties through suppression of both liver fatty acid synthesis and postprandial hypertriacylglycerolemia by inhibition of pancreatic lipase.     

江苏东山山地枇杷果实品质与果园土壤、叶片和果实矿质元素的关系

以江苏省苏州吴中区山地种植的24个枇杷果园的‘白玉’枇杷为研究对象,采用典型相关分析法研究土壤、叶片和果实矿质元素间及其与果实品质指标的相关性,应用多元线性回归分析法筛选影响枇杷果实品质的土壤、叶片和果实的主要矿质元素和影响叶片矿质元素的主要土壤矿质养分因子,为改善枇杷果实品质的果园营养管理技术提供理论参考依据。结果表明:(1)枇杷果实品质指标在不同果园间存在较大差异。(2)枇杷果实品质主要受其叶片和果实矿质元素含量影响,其中:枇杷单果质量与叶片中N含量呈显著正相关,与果实中N含量呈显著负相关;可溶性固形物含量与叶片中N和Mg元素含量呈极显著正相关,与果实中P、Mn元素含量呈极显著正相关,与果实中Ca、Mg元素含量呈极显著负相关;可滴定酸含量与叶片中N和Zn元素含量呈显著负相关,与果实中N、Mn元素含量呈显著负相关,与果实中Ca元素含量呈显著正相关。(3)果实品质指标与土壤矿质养分含量的相关性较弱,土壤矿质养分主要通过影响叶片矿质元素含量,进而间接影响果实品质,其中土壤中P、K、Ca、Mn、Cu元素对叶片中矿质元素含量影响较大。研究认为,提高土壤中P、K、Zn含量并减少土壤Ca含量是东山山地枇杷果园土壤管理的关键技术途径;提高叶片中N含量以及果实中N、P、Mn含量和减少果实中Ca、Mg含量是改善东山山地枇杷果实品质的关键措施。     

枇杷果实发育过程中糖积累及相关酶活性变化研究

以'青种'、'霸红'和'鸡蛋白'3个枇杷品种为材料,测定不同果实发育时期果实中蔗糖、葡萄糖和果糖含量以及蔗糖代谢相关酶即酸性转化酶(AI)、中性转化酶(NI)、蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性,并对果实中糖积累与酶活性的关系进行了分析.结果表明:在果实膨大期(5月3日)之前,3种枇杷果实的蔗糖、葡萄糖和果糖积累缓慢,之后则迅速积累,存在着明显的转折点;果实成熟(5月23日)之后糖分积累速度趋于平稳.3种枇杷果实在发育过程中转化酶、蔗糖合成酶和蔗糖磷酸合成酶的活性变化与3种糖积累的动态变化趋势相一致.NI和AI活性在果实膨大期之前都较低且没有明显的变化,之后均快速上升;SS和SPS的活性在果实膨大期之前都很低且几乎无变化,随后'鸡蛋白'的活性迅速上升至果实成熟之后便缓慢上升,而'青种'和'霸红'随果实成熟度的增加而升高,但均低于'鸡蛋白'.可见,枇杷果实膨大期是糖分积累代谢活跃期,其糖积累受蔗糖代谢相关酶综合调控.     

(2-Nitroethyl)benzene: a major flower scent from the Japanese loquat Eriobotrya japonica [Rosales: Rosaceae]

(2-Nitroethyl)benzene was identified as a major component of the flower scent of the Japanese loquat Eriobotrya japonica [Rosales: Rosaceae], together with p-methoxybenzaldehyde and methyl p-methoxybenzoate. The corresponding volatiles from chopped leaves did not contain these three compounds. This is the first time that 1-nitro-2-phenyl-ethane has been demonstrated to be a natural product among Japanese plants, although two Japanese millipedes are known to possess the same aromatics.     

In vitro anticancer activity of loquat tea by inducing apoptosis in human leukemia cells

Fresh loquat leaves have been used as folk health herb in Asian countries for long time, although the evidence supporting their functions is still minimal. This study aimed to clarify the chemopreventive effect of loquat tea extract (LTE) by investigating the inhibition on proliferation, and underlying mechanisms in human promyelocytic leukemia cells (HL-60). LTE inhibited proliferation of HL-60 in a dose-dependent manner. Molecular data showed that the isolated fraction of LTE induced apoptosis of HL-60 as characterized by DNA fragmentation; activation of caspase-3, -8, and -9; and inactivation of poly(ADP)ribose polymerase. Moreover, LTE fraction increased the ratio of pro-apoptotic Bcl-2-associated X protein (Bax)/anti-apoptotic myeloid cell leukemia 1 (Mcl-1) that caused mitochondrial membrane potential loss and cytochrome c released to cytosol. Thus, our data indicate that LTE might induce apoptosis in HL-60 cells through a mitochondrial dysfunction pathway. These findings enhance our understanding for chemopreventive function of loquat tea.     

枇杷种质资源的离体保存研究Ⅱ生长抑制剂的影响

在枇杷种质资源离体保存中,加入植物生长抑制剂可以延缓枇杷试管苗的生长速度,延长保存时间。实验结果表明,有利于枇杷种质保存的35种生长抑制剂浓度分别是：多效唑（PP333）2-5mg/L、矮壮素（CCC）25mg/L、脱落酸（ABA）10mg/L;其中浓度为5mg/L的多效唑效果最为理想。高浓度的甘露醇（＞5g/L）对试管苗会造成毒害,不利于枇杷种质的保存;5g/L甘露醇保存效果较好。     

干旱胁迫对枇杷生理特性及生长的影响

以3年生‘大五星’枇杷嫁接苗为试验材料,通过盆栽控水试验设置4个水分处理梯度:对照(CK)、轻度胁迫(LS)、中度胁迫(MS)和重度胁迫(SS),研究不同程度土壤干旱对枇杷幼树的生长和生理特性的影响。结果显示:(1)枇杷的株高、地上和地下生物量随干旱胁迫的增强呈下降趋势。(2)在轻度和中度胁迫下叶片叶绿素含量增加,随着土壤水分的减少,叶绿素含量和叶片相对含水量(LRWC)均显著下降。(3)叶片净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)随着干旱胁迫的加剧均显著下降,其中Gs下降幅度最大,而胞间CO2浓度(Ci)则表现为先下降后上升,重度胁迫时叶片的水分利用率(WUE)最低。(4)干旱的加重使叶片超氧化物歧化酶(SOD)和过氧化物酶(POD)的活性呈现先增加后降低的趋势,过氧化氢酶(CAT)活性在轻度胁迫下最为活跃但在重度胁迫时显著降低,丙二醛(MDA)含量在中度胁迫第10天开始显著升高。(5)随干旱胁迫的加剧游离脯氨酸(Pro)含量增加且在重度胁迫第10天达到最大值,而可溶性蛋白(SP)含量在胁迫后期与对照无显著差异,可溶性糖(SS)含量在重度胁迫后期达到峰值且与对照差异显著。研究表明,在轻度和中度干旱胁迫下,枇杷叶片光合作用受到抑制,但能够积极调控抗氧化酶的活性和渗透调节物质的含量等来增强耐受性,而重度胁迫下,叶片膜系统和光合系统受到损伤,枇杷生长受到严重抑制。     

S02对冷藏枇杷果实品质及活性氧和多胺代谢的影响

以"大红袍"枇杷果实为试材,研究了SO2处理对冷藏枇杷果实活性氧代谢和内源多胺含量变化的影响及与果实木质化败坏的关系。结果表明,SO2可提高超氧物歧化酶(SOD)和过氧化氢酶(CAT)活性,抑制过氧化物酶(POD)活性的上升,减少H2O2的积累。经SO2处理的果实,精胺(Spm)和亚精胺(Spd)含量的变化很小,基本维持在贮前水平上,腐胺(Put)的积累则受到极大抑制,贮藏5周后的果实不出现木质化败坏症状。这些结果表明,SO2可能通过维持活性氧代谢的平衡,抑制活性氧的积累,从而防止果实木质化的发生。     

枇杷冷藏过程中果肉木质化与细胞壁物质变化的关系

“大红袍”和“解放钟”枇杷果实在 1℃下贮藏时 ,细胞壁物质代谢异常 ,果肉硬度持续升高而出汁率逐渐降低 ,果胶酯酶 (PE)和多聚半乳糖醛酸酶 (PG)活性和水溶性果胶含量下降 ,原果胶含量、苯丙氨酸解氨酶(PAL)活性及木质素和纤维素含量不断增加。约经 3周贮藏后 ,果实出现果皮难剥、果肉质地变硬、粗糙少汁的异常劣变现象。在 12℃下贮藏的枇杷果实 ,细胞壁物质代谢正常 ,果肉硬度增加少 ,PE和PG活性及水溶性果胶含量较高 ,无原果胶增加现象 ,PAL活性呈下降趋势 ,木质素和纤维素含量变化不大 ,果实不出现木质化败坏。这些结果表明冷藏枇杷的木质化败坏可能是一种低温失调现象     

枇杷种子的脱水敏感性与膜脂过氧化作用

枇杷种子不耐贮藏,属于脱水敏感的种子。在干燥脱水过程中,子叶和胚轴的超氧物歧化酶（ＳＯＤ） 和过氧化物酶（ＰＯＤ） 活性不断下降,而丙二醛（ ＭＤＡ） 含量及种子浸泡液的电导率不断增加,种子活力逐渐降低。外源０ ．０５ ～０ ．２５ ｍｍｏｌ／Ｌ 的抗坏血酸（ＡＳＡ） ,０ ．０５ ～５ ．０ ｍｍｏｌ／Ｌ 的还原性谷胱甘肽（ＧＳＨ）和０ ．０５ ～０ ．５ ｍｍｏｌ／Ｌ 的Ｃａ２ ＋ 处理能有效地增强种胚防御过氧化的能力,缓解氧自由基对种胚的伤害,提高脱水劣变的种子活力。