Mitigating phospholipid peroxidation of macrophages in stress-induced tumor microenvironment by natural ALOX15/PEBP1 complex inhibitors.

BACKGROUND: The intricate interactions between chronic psychological stress and susceptibility to breast cancer have been recognized, yet the underlying mechanisms remain unexplored. Danzhi Xiaoyao Powder (DZXY), a traditional Chinese medicine (TCM) formula, has found clinical utility in the treatment of breast cancer. Macrophages, as the predominant immune cell population within the tumor microenvironment (TME), play a pivotal role in orchestrating tumor immunosurveillance. Emerging evidence suggests that lipid oxidation accumulation in TME macrophages, plays a critical role in breast cancer development and progression. However, a comprehensive understanding of the pharmacological mechanisms and active components of DZXY related to its clinical application in the treatment of stress-aggravated breast cancer remains elusive. PURPOSE: This study sought to explore the plausible regulatory mechanisms and identify the key active components of DZXY contributing to its therapeutic efficacy in the context of breast cancer. METHODS: Initially, we conducted an investigation into the relationship between the phagocytic capacity of macrophages damaged by psychological stress and phospholipid peroxidation using flow cytometry and LC-MS/MS-based phospholipomics. Subsequently, we evaluated the therapeutic efficacy of DZXY based on the results of the tumor size, tumor weight, the phospholipid peroxidation pathway and phagocytosis of macrophage. Additionally, the target-mediated characterization strategy based on binding of arachidonate 15-lipoxygenase (ALOX15) to phosphatidylethanolamine-binding protein-1 (PEBP1), including molecular docking analysis, microscale thermophoresis (MST) assay, co-immunoprecipitation analysis and activity verification, has been further implemented to reveal the key bio-active components in DZXY. Finally, we evaluated the therapeutic efficacy of isochlorogenic acid C (ICAC) based on the results of tumor size, tumor weight, the phospholipid peroxidation pathway, and macrophage phagocytosis in vivo. RESULTS: The present study demonstrated that phospholipid peroxides, as determined by LC-MS/MS-based phospholipidomics, triggered in macrophages, which in turn compromised their capacity to eliminate tumor cells through phagocytosis. Furthermore, we elucidate the mechanism behind stress-induced PEBP1 to form a complex with ALOX15, thereby mediating membrane phospholipid peroxidation in macrophages. DZXY, demonstrates potent anti-breast cancer therapeutic effects by disrupting the ALOX15/PEBP1 interaction and inhibiting phospholipid peroxidation, ultimately enhancing macrophages' phagocytic capability towards tumor cells. Notably, ICAC emerged as a promising active component in DZXY, which can inhibit the ALOX15/PEBP1 interaction, thereby mitigating phospholipid peroxidation in macrophages. CONCLUSION: Collectively, our findings elucidate stress increases the susceptibility of breast cancer by driving lipid peroxidation of macrophages and suggest the ALOX15/PEBP1 complex as a promising intervention target for DZXY.

Characterization and functional analysis of the MADS-box EgAGL9 transcription factor from the mesocarp of oil palm (Elaeis guineensis Jacq.).

Oil palm (Elaeis guineensis Jacq.) is one of the most important oil crops in the world, and compared to all oil crops, it has the highest productive efficiency. In the present study, a MADS-box transcription factor of the AGAMOUS class, named EgAGL9, was identified by expression profile analysis in the different developmental stages of oil palm mesocarp. Real-time quantitative PCR results confirmed that the expression of EgAGL9 increased rapidly during the last stages of oil palm mesocarp development. Then, three downstream genes, including EgSAD (Stearoyl-ACP desaturase), EgTSA (Tryptophan synthase) and EgSDH (Succinate dehydrogenase), were screened by ChIP-Seq and data analysis. EMSA analysis verified that EgAGL9 interacted with the promoter regions of EgSAD, EgTSA and EgSDH. Moreover, the expression levels of EgSAD, EgTSA and EgSDH were downregulated in EgAGL9-overexpressing protoplasts and calli of oil palm. Compared to WT, the total lipid content and ratio of unsaturated fatty acids in transgenic calli (including oleic acid, linoleic acid and linolenic acid) were significantly decreased. Together, these results revealed that these three EgAGL9-regulated genes are involved in regulatory pathways in the oil palm mesocarp. Compared with previous studies, the present study provides a new research strategy for understanding of the molecular regulatory pathways of lipid metabolism in mesocarp of oil palm. The obtained results will bring a new perspective for a comprehensive understanding of the regulation of the metabolic accumulation in the oil palm mesocarp.

EgMYB108 regulates very long-chain fatty acid (VLCFA) anabolism in the mesocarp of oil palm.

KEY MESSAGE: EgMYB108 regulates VLCFA anabolism in oil palm. Very long-chain fatty acids (VLCFAs), which are fatty acids with more than 18 C, can not only be used as a form of triglyceride (TAG) but also provide precursors for the biosynthesis of cuticle wax, and they exist in plant epidermal cells in the form of wax in higher plants. However, which and how transcriptional factors (TFs) regulate this process is largely unknown in oil palm. In this study, a MYB transcription factor (EgMYB108) with high expression in the mesocarp of oil palm fruit was characterized. Overexpression of EgMYB108 promoted not only total lipid content but also VLCFA accumulation in oil palm embryoids. Subsequently, transient transformation in protoplasts and qRT-PCR analysis indicated that the EgKCS5 and EgLACS4 genes were significantly increased with the overexpression of EgMYB108. Furthermore, yeast one­hybrid assays, dual-luciferase assays and EMSAs demonstrated that EgMYB108 binds to the promoters of EgKCS5 and EgLACS4 and regulates their transcription. Finally, EgMYB108 interacts with the promoters of EgLACS and EgKCS simultaneously and finally improves the VLCFA and total lipid contents; a pathway summarizing this interaction was depicted.. The results provide new insight into the mechanism by which EgMYB108 regulates lipid and VLCFA accumulation in oil palm.

The effectiveness of electro-acupuncture combined with dyclonine hydrochloride in relieving the side effects of gastroscopy: a controlled trial.

BACKGROUND: The present study aimed to explore the effectiveness of electro-acupuncture (EA) in combination with a local anesthetic used in Western medicine in preventing the side effects of gastroscopy. METHODS: A sample group of 150 patients were divided into three groups based on treatment methods: an EA group, a dyclonine hydrochloride mucilage group, and a combined treatment group. In the EA group, EA stimulation was given at the Hegu, Neiguan, and Zusanli acupoints; in the dyclonine hydrochloride mucilage group, patients took 10 mL of dyclonine hydrochloride mucilage orally; in the combined treatment group, prevention of side effects was attempted by administration of both acupuncture and oral local anesthetic. The incidences of nausea, emesis, salivation, cough, restlessness, and breath holding during gastroscopy were observed and recorded for the three groups. Mean arterial pressure, heart rate, and oxygen saturation were recorded before the examination, and changes in these measures were recorded as the gastroscope passed through the pylorus and after the examination. The visual analogue scale (VAS) values of nausea and emesis, the rate of successful first-pass intubation, and the time of gastroscopy were also recorded. Statistical analysis was performed using R-3.5.3 software. RESULTS: Incidences of side effects (e.g., nausea, emesis, salivation, restlessness, and breath holding) during the examination were lower in the combined treatment group than in the EA group and the dyclonine hydrochloride mucilage group (P<0.05 and P<0.01, respectively). Furthermore, the changes in heart rate and oxygen saturation when the gastroscope passed through the pylorus and after the examination were better in the combined treatment group than in the EA group and dyclonine hydrochloride mucilage group (P<0.01). The VAS values of nausea and emesis, the first-pass success rate, and examination duration were also better for the combined treatment group than for the other two groups (P<0.05 and P<0.01). CONCLUSIONS: EA combined with local anesthesia with dyclonine hydrochloride mucilage can alleviate side effects during gastroscopy, reduce patient pain, and improve the efficiency of the procedure.

A MADS-box gene, EgMADS21, negatively regulates EgDGAT2 expression and decreases polyunsaturated fatty acid accumulation in oil palm (Elaeis guineensis Jacq.).

KEY MESSAGE: EgMADS21 regulates PUFA accumulation in oil palm. Oil palm (Elaeis guineensis Jacq.) is the most productive world oil crop, accounting for 36% of world plant oil production. However, the molecular mechanism of the transcriptional regulation of fatty acid accumulation and lipid synthesis in the mesocarp of oil palm by up- or downregulating the expression of genes involved in related pathways remains largely unknown. Here, an oil palm MADS-box gene, EgMADS21, was screened in a yeast one-hybrid assay using the EgDGAT2 promoter sequence as bait. EgMADS21 is preferentially expressed in early mesocarp developmental stages in oil palm fruit and presents a negative correlation with EgDGAT2 expression. The direct binding of EgMADS21 to the EgDGAT2 promoter was confirmed by electrophoretic mobility shift assay. Subsequently, transient expression of EgMADS21 in oil palm protoplasts revealed that EgMADS21 not only binds to the EgDGAT2 promoter but also negatively regulates the expression of EgDGAT2. Furthermore, EgMADS21 was stably overexpressed in transgenic oil palm embryoids by Agrobacterium-mediated transformation. In three independent transgenic lines, EgDGAT2 expression was significantly suppressed by the expression of EgMADS21. The content of linoleic acid (C18:2) in the three transgenic embryoids was significantly decreased, while that of oleic acid (C18:1) was significantly increased. Combined with the substrate preference of EgDGAT2 identified in previous research, the results demonstrate the molecular mechanism by which EgMADS21 regulates EgDGAT2 expression and ultimately affects fatty acid accumulation in the mesocarp of oil palm.

Structural Optimization of Caffeoyl Salicylate Scaffold as NO Production Inhibitors.

Chlorogenic acid (CGA) has been considered as one of important active components in a number of medicinal herbs. Recently our group demonstrated that caffeoyl salicylate scaffold derived from CGA can be employed for the development of novel anti-inflammatory agents. The most active compound D104 can be a very promising starting point for the further structural optimization. A series of novel caffeoyl salicylate analogs were designed, synthesized, and evaluated by preliminary biological evaluation. The obtained results showed that the two compounds B12 and B13 can not only inhibit production of nitric oxide (NO) in RAW264.7 cells induced by lipopolysaccharides (LPS) effectively, but also have high safety in in vitro cytotoxic test, which could be comparable with D104. Molecular docking study on the peroxisome proliferator-activated receptor γ (PPARγ) protein revealed that compounds B12 and B13 can follow the same binding mode with D104, and the carboxyl group of caffeoyl salicylate scaffold might play a key role in the interaction with protein target, which implied the carboxyl group should be retained in the further optimization.

Protective effects of collagen polypeptide from tilapia skin against injuries to the liver and kidneys of mice induced by d-galactose.

We wished to investigate the role of a tilapia skin collagen polypeptide (TSCP; molecular weight <3 kDa) in alleviating liver and kidney injuries in aging mice induced by d-galactose (d-gal) and its underlying mechanism of action. First, we characterized TSCP. TSCP was passed through a 3-kDa ultrafiltration membrane, desalted in water by a solid-phase extraction column, purified further by reverse phase-high performance liquid chromatography, and analyzed by electrospray ionization mass spectrometry and tandem mass spectrometry. TSCP contained 17 types of amino acids (AAs) and 41 peptide chains of length 7 AAs to 22 AAs. The content of free AAs and total AAs of TSCP was 13.5% and 93.79%, respectively. Next, we undertook animal experiments. Mice were injected once-daily with D-gal (300 mg/kg body weight, s.c.) for 8 weeks, and TSCP was administered simultaneously once-daily by intragastric gavage. TSCP could visibly improve the decreased body weight, depressed appetite, and mental deterioration of mice triggered by d-gal. TSCP could also alleviate d-gal-induced damage to the liver and kidneys according to histopathology (especially high-dose TSCP). Consistent with these macroscopic and pathologic changes, TSCP could also prevent d-gal-induced increases in serum levels of alanine aminotransferase, aspartate transaminase, alkaline phosphatase, lipid peroxidation, creatinine and uric acid, as well as decreases in serum levels of immunoglobulin (Ig)G and IgM. Moreover, TSCP improved the activities of superoxide dismutase, catalase, and glutathione peroxidase, but also inhibited the increases in the levels of malondialdehyde and inducible nitric oxide synthase expression in the liver and kidneys of d-gal-treated mice. These results suggest that TSCP can alleviate the injuries to the liver and kidneys in aging mice induced by d-gal, and that its mechanism of action might be, at least partially, associated with attenuation of oxidative stress and enhancement of immune function.

Design, synthesis, and anti-inflammatory activity of caffeoyl salicylate analogs as NO production inhibitors.

Chlorogenic acid (CGA) has been reported to exhibit potent anti-inflammatory activity. However, the development of anti-inflammatory agent based on CGA has not been investigated. In this paper, a series of caffeoyl salicylate compounds derived from CGA were designed, synthesized, and evaluated by LPS-induced nitric oxide synthase inhibition and QRT-PCR technique. Most compounds showed modest activity to inhibit production of nitric oxide (NO) in RAW 264.7 cells induced by lipopolysaccharides (LPS). Among these compounds, QRT-PCR and western blotting results indicated that compounds 6b, 6c, 6f, 6g and D104 that possess 5-member ring or 6-member ring caused a significant inhibition against expression of the iNOS2 in LPS-induced macrophages. In addition, cytotoxic assay displayed most derivatives have good safety in vitro. This new promising scaffold could be further exploited for the development of anti-inflammatory agent in the future.

Discovery, design and synthesis of 6H-anthra[1,9-cd]isoxazol-6-one scaffold as G9a inhibitor through a combination of shape-based virtual screening and structure-based molecular modification.

Protein lysine methyltransferase G9a is widely considered as an appealing antineoplastic target. Herein we present an integrated workflow combining shape-based virtual screening and structure-based molecular modification for the identification of novel G9a inhibitors. The shape-based similarity screening through ROCS overlay on the basis of the structure of UNC0638 was performed to identify CPUY074001 contained a 6H-anthra[1,9-cd]isoxazol-6-one scaffold as a hit. Analysis of the binding mode of CPUY074001 with G9a and 3D-QSAR results, two series compounds were designed and synthesized. The derivatives were confirmed to be active by in vitro assay and the SAR was explored by docking stimulations. Besides, several analogues showed acceptable anti-proliferative effects against several cancer cell lines. Among them, CPUY074020 displayed potent dual G9a inhibitory activity and anti-proliferative activity. Furthermore, CPUY074020 induced cell apoptosis in a dose-dependent manner and displayed a significant decrease in dimethylation of H3K9. Simultaneously, CPUY074020 showed reasonable in vivo PK properties. Altogether, our workflow supplied a high efficient strategy in the identification of novel G9a inhibitors. Compounds reported here can serve as promising leads for further study.

[Analysis of four flavonoids in Lysimachia clethroides using ionic liquid-assisted extraction].

In order to established a method for simultaneous determination of isoquercitrin, astragaline, quercetin and kaempferol in Lysimachia clethroides, the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM]PF6) methanol was used as the ultrasound-assisted extraction solvent combing with RP-HPLC. A Purospher star RP-C1 column was used with the mobile phase of aceto- nitrile, methanol and 0. 4% phosphate acid by gradient elution at the detection wavelength of 360 nm. The flow rate was 0.7 mL x min(-1), and the column temperature was the room temperature. Under the optimized conditions, the linear ranges were 2.54 x 10(-2)-2. 54, 2.50 x 10(-2)- 2.50, 1.54 x 10(-3)-0.154, 1.49 x 10(-3)-0.149 microg for isoquercitrin, astragaline, quercetin and kaempferol, respectively. The average recoveries of the four constituents were 101.1%, 98.90%, 101.0%, 101.6%, respectively. The method was green, simple, rapid and accurate, and provided a valid method for analysis of isoquercitrin, astragaline, quercetin and kaempferol in L. clethroides.

[Determination of oleanic acid and paeoniflorin in Paeonia lactiflora by ultrasound-assisted ionic liquid-reversed phase liquid chromatography].

Four kinds of ionic liquids [BMIM] Br, [BMIM] BF4, [BMIM] PF6, [HMIM] PF6 were used to analyze the content of oleanic acid and paeoniflorin in Paeonia lactiflora with ultrasonic-assisted extraction coupled with HPLC. The chromatographic column, Purospher star RP-C18 (4.6 mm x 250 mm, 5 µm), was used. Acetonitrile and water (90:10) as mobile phase was used to determine the content of oleanic acid with a gradient elution and flow rate at 1.00 mL · min(-1), detection wavelength at 210 nm, chromatographic column temperature at room temperature. Paeoniflorin content was determined using acetonitrile and water (18:82) as mobile phase with a gradient elution and flow rate at 1.00 mL · min(-1), detection wavelength at 250 nm, the chromatographic column temperature at room temperature. The result show that oleanic acid has the highest extraction yield when the conditions are solid-liquid ratio of 1:80 (g · mL(-1)), and the [BMIM] Br methanol solution concentration of 0.6 mol · L(-1). Under the optimal extraction conditions, the content of oleanic acid from 0.24 to 3.76 µg showed a good linearity (r = 0.9999), the average recovery was 97.20%. Paeoniflorin has the highest extraction yield when the conditions are solid-liquid ratio of 1:130 (g · mL(-1)), and the [C4 MIM] PF6 methanol solution concentration of 0.6 mol · L(-1). Under the optimal extraction conditions, paeoniflorin content from 0.42 to 4.20 µg showed a good lin- earity (r = 1.000), the average recovery was 98.84%. This method is simple and reliable, its repeatability is also very good. It has important significance in the study P. lactiflora of ionic liquid microextraction.

Combined Molecular Docking, 3D-QSAR, and Pharmacophore Model: Design of Novel Tubulin Polymerization Inhibitors by Binding to Colchicine-binding Site.

Interference with dynamic equilibrium of microtubule-tubulin has proven to be a useful tactics in the clinic. Based on investigation into the structure-activity relationship (SAR) studies of tubulin polymerization inhibitors obtained from several worldwide groups, we attempted to design 691 compounds covering several main heterocyclic scaffolds as novel colchicine-site inhibitors (CSIs). Evaluated by a series of combination of commonly used computer methods such as molecular docking, 3D-QSAR, and pharmacophore model, we can obtain the ultimate 16 target compounds derived from five important basic scaffolds in the field of medicinal chemistry. Among these compounds, compound A-132 with in silico moderate activity was synthesized, and subsequently validated for preliminary inhibition of tubulin polymerization by immunofluorescence assay. In additional, the work of synthesis and validation of biological activity for other 15 various structure compounds will be completed in our laboratory. This study not only developed a hierarchical strategy to screen novel tubulin inhibitors effectively, but also widened the spectrum of chemical structures of canonical CSIs.

[Effects of Electroacupuncture Intervention on Oxygen Free Radicals and Expression of Apoptosis-related Proteins in Rats with Ischemic Learning and Memory Disorder].

OBJECTIVE: To observe the effect of electroacupuncture (EA) therapy on levels of oxygen free radicals (OFR) and hippocampal apoptosis-related protein expression in ischemic learning-memory disorder rats so as to investigate its mechanisms underlying improvement of ischemic learning-memory impairment. METHODS: A total of 60 SD rats were randomly divided into sham operation (sham), model, medication, and EA groups, with 15 rats in each group. The learning-memory disorder model was made by occlusion of bilateral carotid arteries. EA (2- 3 Hz, 2 mA) was applied to "Zhi San Zhen" ["Shenting" (GV 24) and bilateral "Benshen" (GB 13)] for 30 min, once a day for 3 weeks. The rats of the medication group were treated by lavage of Aricept (0.03 mg . kg(-1) . d(-1)), once daily for 3 weeks. The rats' learning-memory ability was detected by Morris water maze tests and the state of hippocampal apoptosis cells was observed by light microscope after TUNEL staining and the expression of hippocampal Bcl-2, Bax and Caspase-3 proteins was detected by immunohistochemistry. Serum and hippocampal superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity and malondialdehyde (MDA) contents were detected by chemical colorimetric analysis. RESULTS: Compared with the sham group, the escape latencies (place-navigation) after modeling were evidently prolonged, and the times of target-platform crossing in 90 sec (spatial probe test) considerably reduced in the model group (P<0.01), suggesting an impairment of learning-memory ability. After the treatment for 21 d, the increased escape latency and the reduced target-platform crossing time in both EA and medication groups were reversed in comparison with the model group (P<0.01), suggesting an improvement of memory ability, and the effect of the EA group was significantly superior to that of the medication group (P<0.05). Compared with the sham group, the number of apoptotic cells in hippocampal CA 1- CA 3 regions, and the expression levels of hippocampal Bcl-2, Bax and Caspase-3 proteins, and serum and hippocampal MDA contents were significantly increased in the model group (P<0.01), while serum and hippocampal SOD and GSH-Px levels obviously decreased in the model group (P<0.01). After the treatment for 21 days, compared to the model group, the number of the apoptotic cells, the expression levels of hippocampal Bax and Caspase--3 proteins, and the contents of serum and hippocampal MDA were notably decreased in the EA and medication groups (P<0.01), whereas, Bcl-2 protein expression levels, and serum and hippocampal SOD and GSH-Px activity were notably up-regulated in the EA and medication groups (P<0.01). The effects of EA group were obviously superior to those of medication group in increasing hippocampal Bcl-2 immunoactivity, serum SOD and GSH-Px and hippocampal GSH-Px activity and in down-regulating serum MDA level (P<0.01, P<0.05). CONCLUSION: Electroacupuncture intervention can improve learning-memory ability in ischemic learning-memory disorder rats which may be associated with its effects in reducing blood and hippocampal OFR contents and hippocampal cellular apoptosis.

[Triterpenes constituents from male flowers of Eucommia ulmoides].

Nine triterpenes compounds were isolated from the male flowers of Eucommia ulmoides by recrystallization and chromatographic techniques over silica gel, Sephadex LH-20, and RP-18 gel. Their chemical structures were identified on the basis of spectral analysis and as 3-oxo-12-en-ursane-28-O-α-L-arabinofuranosyl (1 --> 6) -ß-D-glucopyranoside (1), 2α, 3ß-dihydroxyurs-12-en-28-oic acid(28 --> 1) -ß-D-glucopyranosyl ester (2), ursolic acid (3), α-amyrin (4), uvaol (5), ursolic acid acetate (6), 3-O-acetate oleanoic acid (7), betulinic acid (8), and betulinol (9). Compound 1 was a new compound, and compounds 2, 4-7 were isolated from the Eucommiu genus for the first time. Cytotoxic activity was tested for all the compounds against K562 and HepG2 cells. The results showed that only compound 3, exhibited cytotoxic activity.

Design, synthesis, biological evaluation, and molecular modeling study of 4-alkoxyquinazoline derivatives as potential VEGFR2 kinase inhibitors.

A series of novel 4-alkoxyquinazoline derivatives were prepared and synthesized and their biological activities were evaluated as potential inhibitors of vascular endothelial growth factor receptor 2 (VEGFR2). Of these compounds, compound 3j demonstrated the most potent inhibitory activities against VEGFR2 tyrosine kinase and cell proliferation, the IC50 values of this compound reaching up to 2.72 nM and 0.35 µM, respectively, compared with Tivozanib (3.40 nM and 0.38 µM). The obtained results, along with a 3D-QSAR study and molecular docking that was used for investigating the probable binding mode, could provide an important basis for further optimization of compound 3j as a potential tyrosine kinase inhibitor.

[Study on the extraction of polyphenol from Scindapsus officinalis with ultrasonic wave technology optimized by central composite design-response surface method].

OBJECTIVE: To optimize ultrasonic extraction technology process conditions of polyphenol from Scindapsus officinalis by the response surface method. METHODS: Based on ethanol concentration, ultrasonic time, the liquid-solid ratio of single factor experiment, the principle of design for 3 star factor 3 level response surface methodology was applied. With FC extraction method for determination of polyphenols, the response surface optimization extraction conditions were studied. RESULTS: The ethanol concentration of 61.14%, ultrasonic wave extracting time of 59.73 min and the ratio of solvent volume of 27.72:1 (Extract 3 times) were selected as the optimum conditions,the extraction yield of polyphenols was 1.352%, with the theoretical 1.361% for the relative error of -0.66%. CONCLUSION: Ultrasonic extraction is a good method for saving time, energy and material,and can be applied to the polyphenols extraction. Central composite design-response surface optimization can get better ecasting results.

[Cloning full-length homologous cDNAs of pollen allergens in Humulus Scandens(Lour.) Merr by degenerate primer].

AIM: To establish a stable and reliable method for fast cloning homologous genes of pollen allergens in allergen-containing plants. METHODS: Degenerate primers were designed based on the bioinformatic analysis of numerous allergens available from the database. Subsequent amplification of the allergen genes was conducted in the weed pollen cDNA pool by a selective PCR profile. Following the truncated gene cloning, RACE method was used to isolate full-length cDNA. Gene function was deduced by sequence alignment in GenBank database. The degenerate ability of the primer was compared with the full-length cDNA sequences. RESULTS: Three full-length cDNAs were obtained. Sequence analysis showed that these new genes shared as high as 79%-85% homology with a large amount of known allergen profilins and were hence regarded as members of panallergen profilin family. Comparing these genes with the degenerate primers that were initially used in truncated gene cloning revealed that alternative nucleotide degeneracy occurred beyond the degenerate site predesigned, suggesting that further degeneracy was expanded by Touchdown-gradient PCR. CONCLUSION: Cloning of homologous genes or allergen genes can be efficiently achieved by using the combination of degenerate primer with Touchdown-gradient RT-PCR in the species such as Humulus scandens that has not yet been investigated.