Blockade of neutrophil recruitment to tumor sites based on sialic acid-modified nanoplatforms enhances the efficacy of checkpoint blockade immunotherapy

Checkpoint inhibitors are designed to rejuvenate depleted or suppressed T cells in the tumor microenvironment,relying on the immune system to control and kill tumors.However,accumulating evidence indicates that tumor-infiltrating neutrophils impede the proliferation and activation of T cells and determine the resistance to checkpoint blockade and chemotherapy.In this study,sialic acid ligand-modified colchicine derivative phospholipid complexes specifically targeted tumor-associated neutrophils in the peripheral blood,blocked neutrophil accumulation in tumors,and attenuated the inhibitory effect of infiltrating neutrophils on T cells.Neutrophil blocking therapy enhanced the immunotherapy effect of the PD-L1 antibody in S180 advanced tumors and 4T1 breast cancer.Our study found that PD-L1 antibody monotherapy increased the tumor infiltration of immunosuppressive neutrophils.Combination therapy with neutrophil blocking can greatly reduce tumor-infiltrating neutrophils and increase the proliferation of cytotoxic CD8^(+) T lymphocytes in the tumor.The combination therapy significantly improved the survival rate of mice with advanced S180 tumors and increased the sensitivity of immune checkpoint inhibitors to 4T1 cold tumors.

不同浓度外源SA对“赤霞珠”果实品质的影响

以8年生酿酒葡萄品种“赤霞珠”为试验材料,在葡萄转色期7月下旬到8月上旬喷施SA,探究在果实发育中SA对果实品质的影响,为改善酿酒葡萄品质提供参考。结果表明,对葡萄叶面喷施SA,整个生长周期“赤霞珠”百粒重无显著差异,葡萄进入转色期后,各SA处理下葡萄果实中糖类物质均逐渐增加,有机酸含量逐渐减少,采收期时,糖类物质含量达到最高,有机酸含量达到最低。采收期(花后110 d),5 mmol/L SA处理可以明显降低葡萄中可滴定酸含量,3 mmol/L SA处理可以显著提高葡萄果实中糖类物质和酚类物质含量。3 mmol/L SA处理有利于“赤霞珠”葡萄果实品质的改善。

盐胁迫下SA在大花烟草中以剂量依赖方式调节种子萌发和生长

以改造的大花烟草(Nicotiana alata)即早花烟草为试材,研究在1500 mmol·L^(-1)氯化钠(NaCl)胁迫下,不同浓度梯度外源水杨酸(SA)处理下早花烟草种子的萌发情况和植株的生长状况,分析其过氧化物酶(POD)酶活性、超氧化物歧化酶(SOD)酶活性和活性氧(ROS)含量,及其作用机制.研究结果表明,适量外源SA可以缓解盐胁迫对早花烟草萌发的毒害.经0.05~1.00 mmol·L^(-1) SA处理,盐胁迫下早花烟草种子的发芽势、发芽率、发芽指数及活力指数上升,但随着SA浓度继续升高,其缓解效应随之降低.盐胁迫下的早花烟草生长已经受到严重抑制.喷施0.5~1.5 mmol·L^(-1) SA后,叶片大小和鲜重、根系的大小和鲜重都明显升高;且喷施0.5~2.0 mmol·L^(-1) SA叶片中SOD和POD活性均呈现先降低后上升的趋势;ROS含量呈现先降低后上升的趋势;叶绿素含量呈现出先上升后降低的趋势.这些结果表明:SA调节耐盐性可能以剂量依赖的方式发生,在外源施加适量浓度的SA提高抗氧化酶活性,能有效地消除过量的ROS,避免ROS积累,降低叶片中叶绿素含量及对光系统和光合碳同化过程中多种酶的伤害,维持较高的光合速率.

Effects of Acetylsalicylic Acid (ASA) and Ethylene Treatments onRipening and Softening of Postharvest Kiwifruit

Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at endogenous salicylic acid (SA) levels and other senescence-related factors duringfruit ripening and softening at 20 ℃. The level of endogenous SA in ripening fruits declined and a closerelationship was observed between the change at endogenous SA level and the rate of fruit ripening andsoftening. ASA treatment elevated SA level in the fruit, slowed down the increases in lipoxygenase (LOX)and allene oxide synthase (AOS) activities, decreased the O22-. production in the preclimacteric phase andthe early phase of ethylene climacteric rise, maintained the stability of cell membrane, inhibited ethylenebiosynthesis, postponed the onset of the ethylene climacteric, and delayed the process of fruit ripeningand softening. On the contrary, application of ethylene to ripening kiwifruit resulted at a lower SA level, anaccelerated increases in the activities of LOX and AOS and the rate of O22-. production, an elevated relativeelectric conductivity and an advanced onset of ethylene climacteric, and a quicker fruit ripening andsoftening. It is suggested that the effects of ASA on ripening kiwifruit can be attributed to its ability toscavenge O22-. and/or to maintain stability of cell membrane.

血清HIF-1α、LDH、SA水平对初诊骨髓增生异常综合征疗效的预测价值

目的探讨血清缺氧诱导因子1α(HIF-1α)、乳酸脱氢酶(LDH)、唾液酸(SA)水平对初诊骨髓增生异常综合征(MDS)疗效的预测价值。方法选择初诊MDS患者86例(观察组),另选同期体检健康的志愿者33例(对照组),采集所有研究对象外周静脉血,离心留取血清,采用酶联免疫吸附试验检测血清HIF-1α、LDH、SA。以血清HIF-1α、LDH、SA水平的中位数为临界值,将初诊MDS患者分为血清HIF-1α、LDH、SA高水平者与低水平者。规范治疗4个疗程后,评价不同血清HIF-1α、LDH、SA水平初诊MDS患者疗效。采用受试者工作特征(ROC)曲线分析血清HIF-1α、LDH、SA水平对初诊MDS患者治疗未缓解的预测价值。结果观察组血清HIF-1α、LDH、SA水平均高于对照组(P均<0.01)。血清HIF-1α、LDH、SA高水平者分别为43、45、42例,其低水平者分别为43、41、44例,血清HIF-1α、LDH、SA低水平者疗效均优于其高水平者(P均<0.05)。ROC曲线分析显示,血清HIF-1α、LDH、SA水平单独与三者联合预测初诊MDS患者治疗未缓解的曲线下面积分别为0.759、0.758、0.769、0.904,血清HIF-1α、LDH、SA水平联合预测初诊MDS患者治疗未缓解的曲线下面积高于三者单独(P均<0.05)。结论初诊MDS患者血清HIF-1α、LDH、SA水平显著升高,并且其水平与疗效有关;血清HIF-1α、LDH、SA水平对初诊MDS患者疗效均有一定预测价值,三者联合时预测价值更高。

Application of advanced oxidation processes for removing salicylic acid from synthetic wastewaters

In this study,advanced oxidation processes(AOPs) such as anodic oxidation(AO),UV/H_2O_2 and Fenton processes(FP) were investigated for the degradation of salicylic acid(SA) in lab-scale experiments.Boron-doped diamond(BDD) film electrodes using Ta as substrates were employed for AO of SA.In the case of FP and UV/H_2O_2,most favorable experimental conditions were determined for each process and these were used for comparing with AO process.The study showed that the FP was the most effective process under aci...

Quantitative analysis of sialic acids in Chinese conventional foods by HPLC-FLD

Background: Sialic acids are a family of ninecarbon sugar compounds with carboxylic acyl derivatives. It exists in bacteria, fish, mammals and other living organisms, participates in and regulates many important life events, such as cell recognition, membrane flow, endocytosis and so on. Sialic acid is usually located in the outermost layer of the sugar part of the cell membrane and the key positions of secreted glycoconjugates (glycolipids, glycoprotein and lipopolysaccharide). Sialic acid (Sia) is an important material foundation for variety of the structure and founction of glycoconjugates. Sia has been known as nearly 50 members, including N-acetylneuraminic acid (Neu5Ac), N-glycoulylneuraminic acid (Neu5Gc) and deaminoneuraminic acid (KDN) as its core monomer. The rest of the sialic acids are derived from these three monomers. The contents of Sia in Chinese food products are unknown. Objective: To determine the contents of Sia in raw and cooked red meat, seafood, poultry and so on. Design: The following food products were purchased from a Chinese supermarket: pork, beef, lamb, salmon, cod, tuna, cow milk, cheese, butter, duck, chicken and chicken eggs. Human milk was collected from Xiamen Maternity and Child Health Care Hospital (Xiamen, China). All tissues were homogenized and hydrolyzed with 0.05 M, 0.1 M and 0.2 M TFA for 150 min at 80°C in dark, respectively. The concentrations of Neu5Ac, Neu5Gc and KDN were determined by using HPLC with fluorescence detector. Results: The contents of total Sia (μg/g tissue or μg/mL liquid sample) in Chinese raw meat were highest in lamb (269.60), followed by pork (254.88), duck (200.63), chicken (162.86) and beef (88.03). The percentages of Neu5Gc were 36.08%, 26.48%, 0%, 0% and 28.40%, respectively. Cod contained higher levels of Sia (171.63) than salmon (104.43) and tuna (77.98). Only Neu5Ac was 50 found in detected aquatic product. Egg yolk contained the highest level of Sia (682.04), and a higher level of Sia (390.67) was found in the egg white. Also our result showed that human milk contained extremely high level of Sia (602.55). Neu5Ac was the predominant form of Sia in all the deteced samples. KDN was found in cow milk only among the samples, the content was 1.14 μg/g. Conclusion: The highest content of Sia in examined Chinese foods was found in 56 eggs, followed by lamb, pork, duck, cod, chicken, salmon, beef and tuna. Knowledge of the Sia content in conventional foods may help us to better understand possible medical disorders involving the uptake of the “non-human” Neu5Gc from our diet.

Application of sialic acid/polysialic acid in the drug delivery systems

The properties of modified biomaterial are gaining more and more importance in drug delivery systems.Sialic acid(SA)and polysialic acid(PSA)serve as endogenous substances,which are non-immunogenic and biodegradable.At the same time,SA modification of the drugs/carriers can enhance the uptake of tumor cell and retention in brain;PSA modifi-cation can reduce the immunogenicity of the proteins or polypeptides and increase circulation time of the modified drugs/carriers in the blood,thus achieving active targeting effect.These properties offer a variety of opportunities for applications in drug delivery systems.This article summarizes the biological functions of SA and PSA and presents the technologies of SA/PSA modified small molecule drugs,proteins and carriers in drug delivery systems.

Structural Aberrations of Cellular Sialic Acids and Their Functions in Cancer Metastases

Sialic acids (neuraminic acids) are a special series of 9 carbon ring negatively charged carbohydrates, which has been found to be selectively changed in malignant cells from structures (both synthesis and structure modifications) to functions (up and down regulation in cells). Sialic acids, in single forms or conjugates, have been systematically studied both in lab and in clinics by GC, GC MS, NMR, HPTLC, HPLC and other modern analytical means. Sialic acids and related conjugates are predicted to be used in cancer diagnosis, cancer prognostic forecasting, designing of cancer chemotherapy regimens, uncovering carcinogenetic processes and neoplasm metastasis. Tumor cell regulative systems and pathways are correlated with sialic acids, which can be applied to prognostic evaluation of cancer patients, and antimetastatic chemotherapy by sialic acid derivatives and analogues. Searching for new biological characteristics of sialic acids in cells have also been extensively studied these days. In this paper, main stream discoveries and advancements are provided , also discussions of possible mechanisms and hypotheses are invoked.

腹腔镜低位前切除术治疗直肠癌的疗效及对SAA、SOD、SA、免疫因子的影响

目的 研究腹腔镜低位前切除术(Lap-LAR)治疗直肠癌(RC)及对血清淀粉样蛋白A(SAA)、超氧化物歧化酶(SOD)、唾液酸(SA)及免疫因子的影响。方法 选择2015年1月~2016年12月入住我院的RC患者126例,依照随机数字表法分为观察组与对照组,各63例。观察组行Lap-LAR,对照组行开腹切除术。观察两组术中出血量、手术时间、远端切缘长度、清扫淋巴结数目、术后引流量、术后恢复通气时间等围术期指标,术前及术后7d血清SAA、SOD、SA水平,血清CD3+、CD4+、CD8+、CD4+/CD8+及NK细胞等免疫因子水平,术后1、6个月静息向量容积、收缩向量容积、最大静息压、最大收缩压等肛门动力学指标及术后并发症,术后复发、转移及3年生存情况。结果 观察组术中出血量、手术时间、远端切缘长度、术后引流量、术后恢复通气时间等均小于对照组,差异均有统计学意义(P<0.05)。两组清扫淋巴结数目比较差异无统计学意义(P>0.05)。术后7d,两组血清SAA、SOD、SA及CD3+、CD4+、CD8+、CD4+/CD8+及NK细胞水平比较差异无统计学意义(P>0.05)。术后1、6个月,观察组静息向量容积、收缩向量容积、最大静息压、最大收缩压等肛门动力学指标均大于对照组,差异均有统计学意义(P<0.05)。观察组术后并发症发生率低于对照组,差异有统计学意义(P<0.05)。两组术后复发率、转移率及3年生存率比较差异均无统计学意义(P>0.05)。结论 Lap-LAR治疗低位RC可有效切除病灶,解除免疫抑制,改善血清SAA、SOD、SA水平,具有创伤小、并发症发生率低、术后恢复快等优势。

ROLE OF SIALIC ACID RESIDUES IN IRON BINDING BY HUMAN LACTOFERRIN

Lactoferrin(Lf-α)is a major constithent of the secondary granules of neutrophils, and is thought to be involved in bacteriostasis through high affinity binding of plasma Fe required for microbial growth.Lf-αis also the major Fe binding protein in milk. Fe bound to Lf-αis available for metabolic use.but the mechanism of Fe release from Lf-αis unknown.Treatment of human Lf-α with neuraminidase to remove sialic acid residues reduced its ability to bind Fe and caused release of Fe already bound to the protein. Reduction in Fe binding capacity was dependent on time of exposure to and concentration of neuraminidase,and was due to Lf-αloss or degradation. Readdition of sialic arid to desialylated Lf -a using a-2, 6-sialyltransferase restored Fe binding.The results suggest that sialylationdesialylation reactions could play a role in physiologic binding and release of Fe from the very high affinity binding sites of Lf -α.

APOPTOSIS OF EPIDIDYMIS EPITHELIUM AND CONTENT OF EPIDIDYMIS SIALIC ACID FOLLOWING TORSED/DETORSED TESTES IN RAT

Objective To investigate the apoptosis of epididyrnis epithelium and the change of epididymissialic acid following torsed/detorsed testes. Methods Twenty four adult male Sprague-Dawley rats were subjected to unilateral 720 testicular torsion with the duration of 2h and 4h, then repaired. The ischemic epididymis were collected for detecting the content of sialic acid by using spectrophotometry and the apoptosis with TUNEL technique. Results There were no statistically significant difference in the apoptosis of epididymis epithelium [(9.51± 2.78)% vs (6.34±1. 98)%] and the content of epididymis sialic acid(23, 3851 ± 9. 2199mg/mgprot vs 19. 3661 6. 3373mg/mgprot) at 24h between following 2h-torsed/detorsed testes and those of sham group. There were statistically significant difference in the apopotosis of epididymis epithelium[ (46. 81 ±3. 55)% vs (6. 34±1. 98) % ] and the content of epididymis sialic acid (13. 7249±7. 8006mg/mgprot vs 19. 3661±6. 3373mg/mgprot) at 24h between following 4h-torsed/detorsed testes and those of sham group(P <0. 05). Conclusion The results suggest that the sialic acid-secreting-function of epididymis remain normal at 24h following 2h-torsed/detorsed testes, while the apoptosis index of epididymis epithelium do not increase. The epididymis would be injured at 24h following 4h-torsed/detorsed testes, while the apoptosis index increased.

SERUM LIPID-BOUND SIALIC ACID IN LUNG CANCER PATIENTS

Serum lipid-bound sialic acid (LSA) assay was evaluated for differential diagnosis between benign and malignant pulmonary disease.Mean serum LSA for normal controls was 13.7±3.7 mg/dl and the upper limit of the normal value was set at 19.8 mg/dl (95% confidence limit,one side).The specificity was 97.l% (95% confidence interval was 93.8%, 100.0%).The mean for benign pulmonary disease was 1 7.l±5.l mg/dl,the specificity was 89.l% (95% confidence interval was 80.9%,97.3%), and the sensitivity was 10.9%.The mean for malignant pulmonary disease was 27.l±7.9 mg/dl, and the sensitivity was 93.3%(95% confidence interval was 88.5%, 98.1%).The serum LSA levels for different malignant pulmonary diseases were different between small cell carcinoma and adenocarcinoma. The results indicate that serum LSA assay might be used as tumor marker to differentiate lung cancer from normal subjects or benign lung disease.

Bitter Melon (Momordica Charantia) Reduces Serum Sialic Acid in Type2 Diabetics: Evidence to Delay the Process of Atherosclerosis

More than 1000 herbal products have been used by diverse cultures of the world to treat hyperglycemia and among them bitter melon (Momordica charantia) is one of the most popular herbal resource. The beneficial effects of bitter melon is not limited to hypoglycaemia only, but it also ameliorates diet induced obesity, insulin resistance and exhibit cardioprotective effects. The present study attempts to investigate the effect of bitter melon fruit juice on a newly investigated risk factor, sialic acid in type2 diabetics. A total of 40 type2 diabetic patients, divided into group A (n = 20) and group B (n = 20) were investigated during the present study. The patients of group A were following bitter melon fruit juice treatment along with diet control, whereas the patients of group B were on diet control only. Serum sialic acid (SSA) decreased in group A from 66.20 ± 2.30 mg/dl to 63.50 ± 2.10 mg/dl (<0.11) but, increased in group B from 66.50 ± 1.70 mg/dl to 68.20 ± 2.50 mg/dl (<0.12), compared to baseline. Post-treatment between group comparison revealed a significant difference (<0.05). The beneficial effects on fasting plasma glucose (FPG) and glycohemoglobin (HbA1-c) were also greater in group A compared to group B as was the case with blood lipids, weight and blood pressure. The study provides another mechanism for the cardioprotective effect of bitter melon and further strengthens its value in the management of type2 diabetes.

Correlation of Cerebrospinal Fluid Sialic Acid with Various Enzymes in Patients with Meningitis

Meningitis is often associated with cerebral compromise which may be responsible for neurological squeal in nearly half of the survivors. Little is known about the mechanisms of Central Nervous System （CNS） involvement in bacterial meningitis. The present study was undertaken to assess the changes in biochemical parameters including glucose, protein, Sialic Acid （SA） and various enzymes like Aspartate Aminotransferase （AST）, Alanine Aminotransferase （ALT）, Creatine Kinase （CK）, Gamma Glutamyltranspeptidase 7 （GGTP） and Lactate Dehydrogenase （LDH） have been determined in the Cerebrospinal Fluid （CSF） of the meningitis patients （n = 26） and compared with control subjects （n = 26）. Total Protein, CK, SA （P 〈 0.02）, AST （P 〈 0.001） and ALT （P 〈 0.0001） of meningitis patients were significantly higher, whereas, glucose （P 〈 0.05） and Gamma Glutamyltranspeptidase （GGT） （P 〈 0.01 and P 〈 0.05, respectively） were significantly lower than those of the controls. This study suggests that loss of integrity of brain-CSF barriers, sialic acid and enzyme profiles may contribute to the severity and neurological complications of meningitis.

New Extracellular Bacillus subtilis Lectins with Sialic Acid-Specificity

The purpose of this work is to perform a detailed study of carbohydrate specificity of the new extracellular bacilli lectins which is considered to determine mechanisms of the lectins action. Sources of lectins were bacterial strains from Ukrainian collection of microorganisms. The optimized protocol of bacilli lectins isolation and purification included precipitation with ammonium sulfate with subsequent gel filtration chromatography on Sepharose CL-6B. Hemagglutinating activity of bacilli lectins and their fine carbohydrate specificity to sialic acids and their derivatives as well as sialic asid-containing and asialic glycoconjugates were studied. The ability of extracellular bacilli lectins to discriminate a- and 13-conformation of carbohydrate molecule and the type of connection between the monomers was determined. Studied lectins showed the most affinity to glycoconjugates containing both types of sialic acids （N-acetylneuraminic acid （Neu5Ac） and N-glycolylneuraminic acid （NeuGc）） and it is supposed to be a basis of their diagnostic and analytical potential.

Science Letters:Anodic oxidation of salicylic acid at Ta/BDD electrode

Boron-doped diamond （BDD） film electrodes using Ta as substrates were employed for anodic oxidation of salicylic acid （SA）. The effects of operational variables including initial concentration, current density, temperature and pH were examined. The results showed that BDD films deposited on the Ta substrates had high electrocatalytic activity for SA degradation. There was little effect ofpH on SA degradation. The current efficiency （CE） ,aas fbund to be dependent mainly on the initial SA concentration, current density and temperature. Chemical oxygen demand （COD） was reduced from 830 mg/L to 42 mg/L under a current density of200A/m^2 at 30℃.

Effects of Salicylic Acid on the Growth and Some Physiological Characters in Salt Stressed Tomato Plants （ Solanum L ycopersicum）

Excessive soil salinity is an important constraint limiting the distribution of plants in natural habitats, and is an increasingly severe agricultural problem in arid and semi-arid regions. Higher salinity levels caused significant reduction in growth parameters like leaf area, leaf length and root and shoot dry weight. Salicylic acid （SA）, a plant phenolic is now considered as a hormone-like endogenous regulator, and its role in the defence mechanisms against biotic stressors has been well documented. In recent years its role has been widely investigated in abiotic stress （salinity, drought, water deficit and so on）. The aim of the present work was to study the effects of salicylic acid on growth and some physiological characters of salt stressed tomato plants. The presence of salicylic acid at low concentration （0.01 mM） in culture medium riched with NaCl 100 mM （6 g·L^-1） improves the tolerance of tomato cv. Golden Sunrise to salinity. This amelioration results in stimulation of growth and development of plants. The applied of SA in saline medium induce： （i） an increase in chlorophyll content; （ii） a better supply of essential elements in plant growth, such as K＋; （iii） a decrease in toxic ions such Na＋ and CI in aerial organs; and （iv） an additional synthesis of organic solutes and osmoprotectors like proline and proteins. All these results suggest that salicylic acid could be successfully used in alleviating depressive effects of salt on the productivity of the cultivated tomato.

血清SA、CRP、D-二聚体及Fib水平在诊断肺癌转移中的应用价值

目的:研究血清唾液酸、C-反应蛋白、D-二聚体及纤维蛋白原水平在诊断肺癌转移中的应用价值。方法:选取2020年1月-2021年12月山东省聊城市第二人民医院收治的159例肺癌患者为观察组,其中130例转移,29例无转移,另选取154例健康查体者为对照组,测定选定人群血清唾液酸、C-反应蛋白、D-二聚体及纤维蛋白原含量,收集数据并进行统计分析。结果:与对照组比较,观察者血清唾液酸、C-反应蛋白、D-二聚体及纤维蛋白原升高明显,差异有统计学意义(P<0.05)。在观察组中,转移患者与无转移患者比较,血清唾液酸、C-反应蛋白、D-二聚体升高明显,差异有统计学意义(P<0.05),纤维蛋白原变化无明显统计学意义(P>0.05)。结论:血清唾液酸、C-反应蛋白、D-二聚体及纤维蛋白原在肺癌患者诊断中具有重要意义,同时血清唾液酸、C-反应蛋白、D-二聚体对判断肺癌患者是否发生转移具有重要预测价值。

1-甲基环丙烯结合水杨酸处理维持百香果甲基环丙烯结合水杨酸处理维持百香果果实贮藏品质

为延长百香果的贮藏期并保持贮藏过程中的品质,对比研究2 mmol/L水杨酸(salicylic acid,SA)、1 mmol/L 1-甲基环丙烯(1-methylcyclopropene,1-MCP)、1-MCP结合SA处理对紫色百香果果实采后贮藏期间品质、活性氧、抗氧化酶指标的影响。百香果果实经SA、1-MCP和1-MCP结合SA处理后,一定程度抑制乙烯的释放和脂氧合酶(li-poxygenase,LOX)活性,促进几丁质酶(chitinase,CHI)和β-1,3-葡聚糖酶(β-1,3-glucanase,GLU)的活性,增强抗氧化和抗病性作用,降低腐烂率。但因SA可以增强呼吸,故导致凹陷和失重,加快总酸流失;1-MCP抑制呼吸作用,增强超氧化物歧化酶(superoxide dismutase,SOD)活性,有利于控制失重和凹陷,但其对过氧化物酶(peroxidase,POD)活性的影响不利于控制衰老。1-MCP结合SA对POD活性,CHI活性以及GLU活性的正向影响强于单独使用1-MCP或SA处理。因此,1-MCP结合SA通过提高百香果果实的抗氧化能力和抗病能力,降低百香果果实的凹陷、失重和腐烂率,且可有效避免单独使用1-MCP或SA处理的不良作用,协同维持百香果果实采后贮藏品质。