Vietnam Academy of Science and Technology: Journals Online
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Purification of recombinant human interleukin-3 expressed as inclusion bodies in Escherichi coli
No full textHuman interleukin-3 (IL-3) is a hematopoietic growth factor involved in the survival, proliferation and differentiation of multipotent hematopoietic cells. However, recombinant IL-3 is usually expressed as insoluble form (inclusion bodies) in Escherichia coli cells. This state of protein often shows no bioactivity. Herein, we report a simple method for solubilization, refolding and purification of recombinant human IL-3 expressed in E. coli cells. First, IL-3 was expressed in E. coli JM109 (DE3) after being induced with 0.05 mM IPTG at 25 oC. Under these conditions, IL-3 was produced as inclusion bodies with molecular weight of approximately 15 kDa on SDS-PAGE gel (14%). Next, IL-3 pellet was separated from the host soluble proteins using sonication followed centrifugation. Then, two strong denaturants such as urea or guanidine hydrochloride were used to test solubilization of the insoluble IL-3. After that, the resulting soluble IL-3 was renatured and subjected to gel filtration chromatography to collect purified IL-3 protein. Our results showed that fractionates contained a single band of IL-3 with recovery rate of about 30%. Several characteristics of recombinant IL-3 were then analyzed. The cytokine IL-3 showed its high purity with a sharp peak on RP-HPLC chromatagram. The Western blot showed a clear signal band on PVDF membrane to demonstrate its right antigenecity against human IL-3 antibody. Besides, amino acid sequence of this cytokine was confirmed by mass spectrophotometry method. The purified IL-3 cytokine is a potential material for further tests.
First records of the genus Leptophion Cameron (Hymenoptera: Ichneumonidae: Ophioninae) from Vietnam
No full textThe genus Leptophion is recorded for the first time from Vietnam, including new records of three species, viz. L. giganteus Shimizu Watanabe, L. maculipennis (Cameron) and L. radiatus (Uchida), for the country. The comparative morphological and pictorial characters of Vietnamese specimens were given. In addition, variations and in-country distribution of newly recorded species were also provided.
QUANTITATIVE DETERMINATION OF APIGENIN FROM APIUM GRAVEOLENS L. BY HPLC-PDA METHOD
No full textIn recent years, the study of the structure and biological activity of medicinal plants have a particularly important to search for anti-cancer medicine. Apium graveolens L. is a species that has been studied for its ability to anti-cancer, lower blood pressure, antioxidant ... In which, apigenin is the compound that is most interested in this species. Apigenin was isolated from the ethyl acetate extract and performed column chromatography with solvent system n-hexane: ethyl acetate (from 100% to 1: 1) obtained 7 fractions. Fraction 7 was applied on column chromatography with n-hexane: ethyl acetate (2:1). The qualitative and quantitative process of apigenin in Apium graveolens L. by HPLC - PDA method was investigated using reverse phase column VDSpher PUR 100 C18 (25 cm × 4,6 mm, 5 mm). with detection wavelength at 335 nm, the mobile phase is 0.1% acetic acid: acetonitrile (60:40) with isocratic elution, flow rate 1 mL/min; injection volume 20 µL; column temperature 25℃. Validation results showed that the process had high specificity, linearity, repeatability with RSD = 1,000%, accuracy recovery with 99,97%, LOD was 0,1 μg/mL and the LOQ was 0,3 μg/mL
Extraction of polysaccharide from Spirulina platensis - advantage of freeze-thaw method
No full textPolysaccharide is one of the key natural products that profit human living conditions. This study aimed at investigating the polysaccharide extraction from Spirulina platensis (PSP) basing on previous research on optimization of experimental conditions. As a result, the efficiency of raw PSP for four extraction methods was 8.35%, 65%, 76.9% and 85.1% for hot water, lye, ultrasound-assisted and freeze-thaw extraction method, respectively, which was higher than previously reported results. Particularly, the efficiency of pure PSP extraction was highest with 14.89% of the dry matter of raw PSP for freezing-thawing method. To determine the major compounds constructing the pure PSP, the composition of PSP monosaccharides was determined by HPLC. The result showed that major PSP monosaccharides were glucose and galactose, of which glucose composition was up to 85%. Furthermore, pure PSP showed antioxidant activity with IC50 values of 373, 403, 276, and 258 mg/mL for hot water, lye, ultrasound-assisted, and freeze-thaw extraction method, respectively, as compared to IC50 of 101.7 mg/mL for ascorbic acid as control
Association of AhRR rs2292596 with male infertility in 422 Vietnamese individuals
No full textMale infertility is a reproductive disease in men caused by multiple factors ranging from harmful lifestyle habits to endogenous genetic elements. This study aimed to investigate the association between the polymorphism AhRR rs2292596 and male infertility. Total DNA was extracted from blood of 422 Vietnamese samples including 218 non-obstructive azoospermic and oligozoospermic patients and 204 healthy controls. The genotypes of the polymorphism were determined by PCR-RFLP method. The distribution of genotypes and their relationship with male infertility were analyzed by statistical methods. The results indicated that rs2292596 AhRR followed Hardy-Weinberg equilibrium (p-value 0.05). However, there was association between the rs2292596 polymorphism and male infertility in the three models (additive, dominant, and recessive) (p-value 0.05). The investigation would help enrich the knowledge about the influences of genetic factors on male infertility in the Vietnamese population
Improved water solubility of quercetin by preparing complexation with cyclodextrins in binary solvent
No full textThe antioxidant capacity of polyphenols have been widely used in food and pharmaceutical industries. Quercetin (Quer) is a polyphenolic flavonoid that shows several biological effects such as antioxidant, antitumor, antibacterial and antiproliferative effects both in-vitro and in-vivo. However, the solubility of quercetin in water is poor. Thus, it is essential to improve solubility of quercetin in pharmaceuticals by making its complexation with other compounds. In this study, the synthesis of the 2-hydroxypropyl-β-cyclodextrin complex with quercetin (Quer-HPβCD) in the form of nanoparticles in water-ethanol solvents has been carried out. The results showed that the obtained yield of (Quer-HPβCD) complexation in binary solvent was greater than that in pure water. The highest Y value was 80% in a binary solvent with 20% v/v of ethanol. The composition, morphology, structural and thermodynamic properties of the nanoparticles Quer-HPβCD have been determined. This study demonstrated that using mixed water- ethanol solvent and lyophilization technique was able to produce quercetin nanoparticles with significantly smaller particle size. The nanoparticles have a spherical shape with an average size of about 40-60 nm. The results of the phase solubility diagram showed that in water the solubility of quercetin increased and linearly depended on the concentration of host’s molecule while Quer and HP-βCD obtained a 1:1 stoichiometric complex. The stability constant of (Quer-HPβCD) complex was found to be logK = 2.56. The Gibbs energy change of the complexation reaction was found to be -14.60 kJ/mol
Collection, freezing of Ban epididymal sperm and evaluation of in vitro fertility after thawing
No full textMany researches on characteristics of porcine ejaculated semen on popular commercialized breeds collecting at breeding centers or households with pig breeding services have been carried out in Vietnam. However, very few investigation had been dealt with epididymal sperms, especially the ones from boar of Ban, a popular Vietnam native mini-pig breed which is usually freely raised in far rural and mountainous regions in some provinces of Northern Vietnam. In the present study, we surveyed on criteria of epididymal sperms from 4 Ban boars at collection, after freezing and thawing processes, and tested their fertility by an in vitro fertilization and embryo culture experiment. Approximate volume of sperm collected from a Ban boar did not differ (3-4 mL), with sperm concentration from 6.4 x 109 to 11.3 x 109 sperm/mL. Motility varied from 8.7 to 27.0%, whereas vitality was from 58.0 to 85.6%. After freezing and thawing, the motility of sperm slightly decreased to values of 6.3 to 25.7%, and viability significantly decreased to values of 41.3 to 79.6%. No difference was found between rates of abnormal morphology before and after freezing and thawing (10.6 to 31.0% and 12.0 to 32.0%, respectively). A test by in vitro fertilization with Landrace oocytes revealed that two sperm lots had acceptable in vitro fertility with rates of blastocyst formation from 14.4 to 18.8%. In conclusion, a study on collection, freezing and fertility testing of epididymal sperm collected from Ban boars has been carried out. The results of the present study could contribute necessary information as well as standardized sperm lots as important materials to further research on in vitro fertilization of Ban in Vietnam
Berberine encapsulated nanoparticles stimulate osteoblast differentiation in vitro
No full textBerberine has been known as a traditional component for treatment of intestinal-related diseases in Asian countries. Additionally, it possesses a variety of pharmacological properties, which were studied for treating tumor, diabetes, cardiovascular disease, hyperlipidemia, inflammation, bacterial and viral infections, cerebral ischemia trauma, and mental disease. Moreover, berberine has been known as an anti-osteoporotic agent by controlling both osteoclast (bone resorption cells) and osteoblast (bone-forming cells) functions. Beside the beneficial effects of berberine, it has some drawbacks that hindered its applications and resulted in low bioavailability. One of the most drawback characteristics of berberine is that it has poor watery solubility. To overcome these limits, nanotechnology has been used as the primary approach to deliver berberine in different nano-formulations. In this study, a novel berberine nanoparticle (nanoberberine, NBB) with good water dispersion was synthesized to enhance its bioavailability. The result showed that NBB was successfully developed in spherical shape and approximately 559 nm of mean size. Besides, in vitro release study revealed that berberine content release from NBB was 3 to 4 times higher than that from free berberine. Moreover, no cytotoxicity was observed for both NBB and berberine on osteoblast MC3T3-E1 cells at the tested concentrations. Additionally, alkaline phosphatase (ALP) activity, a marker for osteoblast differentiation process, was significantly higher in NBB compared to free berberine at the same test concentrations. This result indicated that NBB could be a potential biological agent for inducing bone formation. Overall, our data indicated that NBB could improve bioavailability, especially osteogenesis activity in vitro compared to free berberine
LIGNIN AND SODIUM LIGNOSULFONATE PRODUCTION FROM THE BLACK LIQUOR GENERATED DURING THE PRODUCTION OF BIOETHANOL FROM RICE STRAW
No full textAbstract-HCTN7. Rice straw is considered as an abundant resource to recover hemicellulose, cellulose, and lignin. Lignin, considered as waste from the biomass pretreatment process for bioethanol production, has numerous applications in value-added chemical products such as lignosulfonate, vanillin, guaiacol, quinones, cresol, … Lignosulfonate was used in various industrial processes such as concrete admixtures, oil well dispersants, dyestuff, coal water slurry dispersants, agricultural chemicals, and other industrial binders. However, lignosulfonate production from rice straw is less attractive due to the difficulty of lignin recovery. Therefore, the objective of this study is to recover lignin and optimize the sulfomethylation of lignin originated from rice straw by sodium sulfite for the highest reaction efficiency to produce lignosulfonate. The effects of reactive conditions including reaction time, temperature, and sodium sulfite/lignin ratio on the sulfomethylation are investigated by experiments and analyzed by response surface methodology (RSM). The results demonstrate that quadratic second-order modeling is compatible with experimental data (R-squared value of 99.9%) and all three factors have a great impact on reaction efficiency (p 0.05). The optimal reaction condition predicted from the empirical modeling is the reaction time of 150 minutes, the temperature of 80oC, and the sodium sulfite/lignin ratio of 1:2 g/g. The verified experiment at the optimal condition produces sodium lignosulfonate with a high reaction efficiency of 96.2% and low surface tension of 48 N/m.