Complement Regulatory Protein CD46 Manifests a Unique Role in Promoting the Migration of Bladder Cancer Cells / 전남의대학술지

CD46 is a membrane-bound complement regulatory protein (mCRP) possessing a regulatory role with the complement system. CD46 protects the host cells from damage by complement. Expression of CD46 is also highly maintained in many cancers, including bladder cancers, and thus functions as a receptor for many cancer therapeutic viruses.In this study we report a unique role of CD46 as a progression factor of cancer cells in bladder cancers. Resulting data from a DNA microarray using CD46-altered HT1376 bladder cancers demonstrated a pool of target genes, including complement C3  chain (C3), matrix Gla protein (MGP), AFAP-AS1, follicular dendritic cell secreted protein (FDCSP), MAM domain containing 2 (MAMDC2), gamma-aminobutyric acid A receptor pi (GABRP), transforming growth factor, beta-induced (TGFBI), a family of cytochrome P450 (CYP24A1), sialic acid binding Ig-like lectin 6 (SIGLEC6), metallothionein 1E (MT1E), and several members of cytokeratins. Subsequent studies using quantitative RT-PCR and Western blot analyses confirmed CD46-mediated regulation of C3, MGP, and keratin 13 (KRT13). MGP and KRT13 are known to be involved in cell migration and cancer cell metastasis. A cell migration assay demonstrated that CD46 enhanced migratory potential of bladder cancer cells. Taken all together, this report demonstrated that CD46 is generally overexpressed in bladder cancers and plays a unique role in the promotion of cancer cell migration. Further detailed studies are needed to be performed to clarify the action mechanism of CD46 and its application to cancer therapeutics.

Physiological intracytoplasmic sperm injection does not improve the quality of embryos: A cross-sectional investigation on sibling oocytes / 대한생식의학회지

Objective@#This study aimed to compare the efficacy of physiological intracytoplasmic sperm injection (PICSI) and intracytoplasmic sperm injection (ICSI) in terms of the fertilization rate and embryo quality using sibling oocyte cycles. @*Methods@#This prospective, cross-sectional study collected data from 76 couples who underwent their first cycle at the Hue Center for Reproductive Endocrinology and Infertility, Vietnam, between May 2019 and November 2021. The inclusion criteria were cycles with at least eight oocytes and a sperm concentration of 5×106/mL. Sperm parameters, sperm DNA fragmentation (SDF), fertilization, and the quality of cleavage-stage embryos on day 2 and blastocysts on day 5 were examined. @*Results@#From 76 ICSI cycles, 1,196 metaphase II (MII) oocytes were retrieved, half of which were randomly allocated to either the PICSI (n=592) or ICSI (n=604) treatment group. The results showed no significant difference between the two groups in terms of fertilization (72.80% vs. 75.33%, p=0.32), day 2 cleavage rate (95.13% vs. 96.04%, p=0.51), blastulation rate (52.68% vs. 57.89%), and high-quality blastocyst rate (26.10% vs. 31.13%, p=0.13). However, in cases where SDF was low, 59 cycles consisting of 913 MII oocytes produced a considerably higher blastulation rate with PICSI than with ICSI (50.49% vs. 35.65%, p=0.00). There were no significant differences between the pregnancy outcomes of the PICSI and ICSI embryo groups following embryo transfer. @*Conclusion@#Using variable sperm quality provided no benefit for PICSI versus ICSI in terms of embryo outcomes. When SDF is low, PICSI appears to be able to produce more blastocysts.

A New Dimeric Lignan from the Stems of Willughbeia edulis

As part of our continued study on the chemical constituents of Willughbeia edulis stems, a new dimeric lignan named edulignan (1) was isolated from its EtOAc-soluble extract. Based on NMR spectroscopic interpretation, the planar structure of 1 has been suggested to have two 2-substituted 4-chromanone subunits with different stereochemical configurations. In addition, the MS/MS analysis of the products obtained by acidcatalyzed hydrolysis of 1 was supportive of its structure. Unfornatually, the new compound 1 did not show α-glucosidase inhibitory activity with an IC 50 value > 250 μM.

Comparing multiplex and multiplex real-time polymerase chain reaction with traditional blood culture in bacterial detection among patients with septicemia

Aims@#This study was aimed to test the specificity of primers and probes with target genes by using multiplex PCR and multiplex real-time PCR methods. These methods were compared with traditional blood culture methods in detecting five bacteria causing sepsis, including Acinetorbacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus.@*Methodology and results@#A total of 587 blood samples from patients diagnosed with sepsis and septic shock were collected at Thanh Nhan Hospital, Hanoi, Vietnam. Each sample was divided into three parts for bacterial culture, multiplex PCR and multiplex real-time PCR to detect the similarity of the two PCR methods with the bacterial culture method. Conditions in multiplex PCR and multiplex real-time PCR were optimized to ensure the successful amplification of target genes. Results showed that the primers and probes were tested completely specific to the target genes and using multiplex PCR and multiplex real-time PCR techniques could detect five pathogens causing sepsis, including A. baumannii, K. pneumoniae, P. aeruginosa, E. coli and S. aureus.@*Conclusion, significance and impact of study@#Both multiplex PCR and multiplex real-time PCR methods have high similarities with the culture method, showing potential in the application of bacteria detection in sepsis.

Isolation and Cytotoxic Potency of Endophytic Fungi Associated with Dysosma difformis, a Study for the Novel Resources of Podophyllotoxin

Endophytic fungi are promising sources for the production of podophyllotoxin-an important anticancer compound, replacing depleted medical plants. In this study, the endophytes associated with Dysosma difformis-an ethnomedicinal plant species were isolated to explore novel sources of podophyllotoxin. Fifty-three endophytic fungi were isolated and identified by morphological observation and ITS-based rDNA sequencing, assigning them to 27 genera in 3 divisions. Fusarium was found the most prevalent genus with a colonization frequency of 11.11%, followed by Trametes (9.26%) and Penicillium (7.41%). Phylogenetic trees were constructed for the endophytic fungi community in two collection sites, Ha Giang and Lai Chau, revealing the adaptation of the species to the specific tissues and habitats. Cytotoxic activity of endophytic fungal extracts was investigated on cancer cell lines such as SK-LU-1, HL-60, and HepG2, demonstrating strong anti-cancer activity of six isolates belonging to Penicillium, Trametes, Purpureocillium, Aspergillus, and Ganoderma with IC 50 value of lower than 10 10 µg/mL. The presence of podophyllotoxin was indicated in Penicillium, Trametes, Aspergillus and for the first time in Purpureocillium and Ganoderma via high-performance liquid chromatography, which implied them as a potential source of this anticancer compound.

Correlations between abnormalities of morphological details and DNA fragmentation in human sperm / 대한생식의학회지

As the associations of sperm DNA fragmentation with morphology have not been examined in detail, this study aimed to investigate the relationship between abnormalities of morphological details and DNA integrity in human sperm. Methods: In this cross-sectional study, men from infertile couples were enrolled at Hue Center for Reproductive Endocrinology and Infertility, Vietnam. Conventional semen parameters, including morphological details, were analyzed following the World Health Organization 2010 criteria. Sperm DNA fragmentation was evaluated using a sperm chromatin dispersion assay. The relationships and correlations between semen parameters, sperm morphology, and the type of halosperm and the DNA fragmentation index (DFI) were analyzed. Results: Among 130 men in infertile couples, statistically significant differences were not found in the sperm halo type between the normal and abnormal sperm morphology groups. The percentage of round-head spermatozoa was higher in the DFI >15% group (16.98%±12.50%) than in the DFI ≤15% group (13.13% ±8.82%), higher values for amorphous heads were found in the DFI >15% group, and lower values for tapered heads were observed in the DFI ≤15% group; however, these differences were not statistically significant. Small-halo sperm and the DFI were positively correlated with round-head sperm (r=0.243, p=0.005 and r=0.197, p=0.025, respectively). Conclusion: The rate of general sperm morphological abnormalities in semen analysis was not related to sperm DNA integrity. However, round sperm heads were closely associated with sperm DNA fragmentation.

SP-8356, a (1S)-(-)-Verbenone Derivative, Inhibits the Growth and Motility of Liver Cancer Cells by Regulating NF-κB and ERK Signaling

Liver cancer is a common tumor and currently the second leading cause of cancer-related mortality globally. Liver cancer is highly related to inflammation as more than 90% of liver cancer arises in the context of hepatic inflammation, such as hepatitis B virus and hepatitis C virus infection. Despite significant improvements in the therapeutic modalities for liver cancer, patient prognosis is not satisfactory due to the limited efficacy of current drug therapies in anti-metastatic activity. Therefore, developing new effective anti-cancer agents with anti-metastatic activity is important for the treatment of liver cancer. In this study, SP-8356, a verbenone derivative with anti-inflammatory activity, was investigated for its effect on the growth and migration of liver cancer cells. Our findings demonstrated that SP-8356 inhibits the proliferation of liver cancer cells by inducing apoptosis and suppressing the mobility and invasion ability of liver cancer cells. Functional studies revealed that SP-8356 inhibits the mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways, which are related to cell proliferation and metastasis, resulting in the downregulation of metastasis-related genes. Moreover, using an orthotopic liver cancer model, tumor growth was significantly decreased following treatment with SP-8356. Thus, this study suggests that SP-8356 may be a potential agent for the treatment of liver cancer with multimodal regulation.

How knowledge of hepatitis B disease and vaccine influences vaccination practices among parents in Ho Chi Minh City, Vietnam

Objective: To assess the influences of the knowledge of parents about hepatitis B virus (HBV) infection and the benefit of HBV vaccination on the practice of HBV vaccination among children. Methods: A prospective cross-sectional study recruited parents whose children, aged 12-24 months, received HBV vaccination at Commune Health Centers (CHCs) in Ho Chi Minh City from Feb. 2016 to Jul. 2017. Parents were interviewed using a questionnaire that included 11-item binary knowledge questions and checked their children's vaccination cards. Results: A total of 768 parents had a mean age of (30.8±5.1) years. The mean knowledge score of the 11- item questions was (7.0±2.4). The knowledge score was positively associated with full and timely HBV vaccination. In addition, children who received complete and timely HBV vaccination were significantly more likely to live in rural areas (Adjusted OR 4.02, 95% CI 2.79-5.79, P<0.001). Also, children whose parents received vaccination information from health care providers, and had knowledge about HBV risk, had a higher rate of full and timely HBV vaccination (Adjusted OR 1.60, 95% CI 1.13-2.29, and Adjusted OR 1.47, 95% CI 1.01-2.13, P all<0.05). Conclusions: Parents possessed a great deal of incorrect knowledge about HBV. More health education from health care providers should target parents living in specific locations and focus on the benefits of HBV vaccine.

Knowledge, attitude, and intention to practice pre-marital testing among midwifery students in Vietnam

Background@#Hereditary diseases are considered one of the most common causes of death and morbidity in infants and children. It significantly burdens the health system, family, and society. Pre-marital testing is one of the most proactive and effective ways to prevent hereditary diseases, infectious diseases, and congenital abnormalities.@*Purpose@#To examine the level of knowledge and attitudes regarding pre-marital testing and the intention to practice pre-marital testing; and, To identify the correlation between knowledge, attitudes, and intention to practice pre-marital testing among midwifery students.@*Methods@#Adescriptive correlational study was conducted from May to July 2020 among 150 midwifery students at the University of Medicine and Pharmacy at Ho Chi Minh City, Vietnam. The research consists of a questionnaire with four main parts: demographic characteristics, knowledge about pre-marital testing, attitudes toward pre-marital testing, and intention to practice pre-marital testing. Descriptive statistics and univariate analysis were used for data analysis. The significance level of the statistical test was set up at α = .05.@*Results@#The average age of students was 21.73 years old, most of them were unmarried (98%). More than three-quarters (80.7%) of them had good knowledge about pre-marital testing and (88.7%) of them had a positive attitude towards pre-marital testing. Most students (94.7%) have an intention to use a pre-marital test and believe in its benefits. Knowledge was positively correlated with intention to practice pre-marital testing (X2 = 5.10, p = 0.02). Likewise, attitude toward pre-marital testing was positively correlated with the intention to practice pre-marital testing (X2 = 12.57, p < 0.001). @*Conclusions@#The findings emphasized the important role of health education which is a keystone in improving pre-marital knowledge, attitudes, and the practice of pre-marital testing to prevent hereditary diseases and improve people's health.

Removal of Manganese and Copper from Aqueous Solution by Yeast Papiliotrema huenov

Papiliotrema huenov was previously reported to be highly tolerant of a range of extremely toxic heavy metals. This study aimed to identify the potential of P. huenov to remove manganese and copper from aqueous solution. Physical conditions which affect removal of Mn(II) and Cu(II) were determined. Optimal temperature for adsorption of both metal ions was 30°C, and optimal pH for maximum uptake of Mn(II) and Cu(II) were 5 and 6, respectively. Under these conditions, living cells of P. huenov accumulated up to 75.58% of 110 mg/ L Mn(II) and 70.5% of 128 mg/L Cu(II) over 120 h, whereas, the removal efficiency of metal ions by dead cells over 1 h was 60.3% and 56.5%, respectively. These results indicate that living cells are more effective than dead biomass for bioremediation, but that greater time is required. The experimental data extends the potential use of P. huenov in biosorption and bioaccumulation of toxic heavy metals to copper and manganese, two of the most common industrial contaminants.

SP-8356, a (1S)-(-)-Verbenone Derivative, Inhibits the Growth and Motility of Liver Cancer Cells by Regulating NF-κB and ERK Signaling

Liver cancer is a common tumor and currently the second leading cause of cancer-related mortality globally. Liver cancer is highly related to inflammation as more than 90% of liver cancer arises in the context of hepatic inflammation, such as hepatitis B virus and hepatitis C virus infection. Despite significant improvements in the therapeutic modalities for liver cancer, patient prognosis is not satisfactory due to the limited efficacy of current drug therapies in anti-metastatic activity. Therefore, developing new effective anti-cancer agents with anti-metastatic activity is important for the treatment of liver cancer. In this study, SP-8356, a verbenone derivative with anti-inflammatory activity, was investigated for its effect on the growth and migration of liver cancer cells. Our findings demonstrated that SP-8356 inhibits the proliferation of liver cancer cells by inducing apoptosis and suppressing the mobility and invasion ability of liver cancer cells. Functional studies revealed that SP-8356 inhibits the mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways, which are related to cell proliferation and metastasis, resulting in the downregulation of metastasis-related genes. Moreover, using an orthotopic liver cancer model, tumor growth was significantly decreased following treatment with SP-8356. Thus, this study suggests that SP-8356 may be a potential agent for the treatment of liver cancer with multimodal regulation.

Application of the artificial neural network to optimize the formulation of self-nanoemulsifying drug delivery system containing rosuvastatin

The objectives of this study were to optimize the formula of the self-nanoemulsifying drug delivery system (SNEDDS)containing rosuvastatin and to evaluate its physicochemical characteristics. The solubility and compatibility ofrosuvastatin in surfactants, cosurfactants, and oil excipients were evaluated. The D-optimal experimental design,created by JMP 15 software, was used for analyzing the effects of excipients on the physicochemical characteristicsof SNEDDS to optimize the rosuvastatin SNEDDS formula. The generated nanoemulsions from Ros SNEDDS werecharacterized for droplet size, polydispersity index, and entrapment efficiency. As a result, Cremophor RH40, Capryol90, and PEG 400 were selected to develop the pseudoternary phase diagram to identify the area capable of selfforming nanoemulsion. As the percentage of rosuvastatin calcium increased from 8% to 12%, the area for optimizingthe formula of Ros SNEDDS decreased. The Ros SNEDDS prepared according to predicted formulas possessed selfemulsification to form nanoemulsion with average droplet size less than 100 nm, polydispersity index less than 0.3,and rosuvastatin entrapment higher than 90%.

Heavy Metal Tolerance of Novel Papiliotrema Yeast Isolated from Vietnamese Mangosteen

Three yeast strains (Hue-1, Hue-8, and Hue-19) with strong heavy metal tolerance were isolated from mangosteen from Hue city, Vietnam. They exhibited identical phenotype and phylogeny. Sequence analysis of the D1/D2 region of the LSU rRNA gene and the internal transcribed spacer (ITS) region demonstrated that the closest relative of these strains is Papiliotrema sp. with 2.12% and 3.55–3.7% divergence in the D1/D2 domain, and ITS domain, respectively. Based on the physiological, biochemical, and molecular data, the three strains belong to a novel species of Papiliotrema genus, for which the namePapiliotrema huenov sp. nov. is proposed. These strains are highly tolerant of heavy metals compared to other yeasts, being able to grow in the presence of 2 mM Pb (II), 2 mM Cd (II), and up to 5 mM Ni (II), but no growth was observed in the presence of 1 mM As (III).

Inhibitory actions of borneol on the substantia gelatinosa neurons of the trigeminal subnucleus caudalis in mice

The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis(Vc) is the first relay site for the orofacial nociceptive inputs via the thin myelinatedAδ and unmyelinated C primary afferent fibers. Borneol, one of the valuable timehonoredherbal ingredients in traditional Chinese medicine, is a popular treatmentfor anxiety, anesthesia, and antinociception. However, to date, little is known asto how borneol acts on the SG neurons of the Vc. To close this gap, the whole-cellpatch-clamp technique was applied to elucidate the antinociceptive mechanismresponding for the actions of borneol on the SG neurons of the Vc in mice. In thevoltage-clamp mode, holding at –60 mV, the borneol-induced non-desensitizinginward currents were not affected by tetrodotoxin, a voltage-gated Na+ channelblocker, 6-cyano-7-nitro-quinoxaline-2,3-dione, a non-N-methyl-D-aspartate (NMDA)glutamate receptor antagonist and DL-2-amino-5-phosphonopentanoic acid, anNMDA receptor antagonist. However, borneol-induced inward currents were partiallydecreased in the presence of picrotoxin, a -aminobutyric acid (GABA)A receptorantagonist, or strychnine, a glycine receptor antagonist, and was almost suppressedin the presence of picrotoxin and strychnine. Though borneol did not show any effecton the glycine-induced inward currents, borneol enhanced GABA-mediatedresponses. Beside, borneol enhanced the GABA-induced hyperpolarization under thecurrent-clamp mode. Altogether, we suggest that borneol contributes in part towardmediating the inhibitory GABA and glycine transmission on the SG neurons of the Vcand may serve as an herbal therapeutic for orofacial pain ailments.

Inhibitory actions of borneol on the substantia gelatinosa neurons of the trigeminal subnucleus caudalis in mice

The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis(Vc) is the first relay site for the orofacial nociceptive inputs via the thin myelinatedAδ and unmyelinated C primary afferent fibers. Borneol, one of the valuable timehonoredherbal ingredients in traditional Chinese medicine, is a popular treatmentfor anxiety, anesthesia, and antinociception. However, to date, little is known asto how borneol acts on the SG neurons of the Vc. To close this gap, the whole-cellpatch-clamp technique was applied to elucidate the antinociceptive mechanismresponding for the actions of borneol on the SG neurons of the Vc in mice. In thevoltage-clamp mode, holding at –60 mV, the borneol-induced non-desensitizinginward currents were not affected by tetrodotoxin, a voltage-gated Na+ channelblocker, 6-cyano-7-nitro-quinoxaline-2,3-dione, a non-N-methyl-D-aspartate (NMDA)glutamate receptor antagonist and DL-2-amino-5-phosphonopentanoic acid, anNMDA receptor antagonist. However, borneol-induced inward currents were partiallydecreased in the presence of picrotoxin, a -aminobutyric acid (GABA)A receptorantagonist, or strychnine, a glycine receptor antagonist, and was almost suppressedin the presence of picrotoxin and strychnine. Though borneol did not show any effecton the glycine-induced inward currents, borneol enhanced GABA-mediatedresponses. Beside, borneol enhanced the GABA-induced hyperpolarization under thecurrent-clamp mode. Altogether, we suggest that borneol contributes in part towardmediating the inhibitory GABA and glycine transmission on the SG neurons of the Vcand may serve as an herbal therapeutic for orofacial pain ailments.

Knowledge and attitude toward COVID-19 among healthcare workers at District 2 Hospital, Ho Chi Minh City

Objective: To assess the knowledge and attitude toward coronavirus disease-2019 (COVID-19) among healthcare workers at District 2 Hospital in Ho Chi Minh City (HCMC). Methods: A cross-sectional study was performed between January 2020 and February 2020 at District 2 Hospital. A systematic random sampling strategy was carried out and the data was collected through a self-administered questionnaire of the knowledge and attitude of healthcare workers regarding COVID-19. Descriptive analysis was reported to describe the demographic, mean knowledge and attitude score of healthcare workers. Inferential statistics including t-test, ANOVA and Spearman's correlation were used to evaluate the relationship between study variables. Results: A total of 327 eligible healthcare workers had a mean score of knowledge and attitude of 8.17±1.3 (range 4-10) and 1.86±0.43 (range 1-5), respectively. They showed good knowledge and a positive attitude. However, approximately two thirds of the participants knew the mode of transmission, the isolation period and treatment (67.0%, 65.8%, and 58.4%, respectively), and 82.3% and 79.8%, respectively, held positive attitude regarding the risk of personal and family members getting illness. There was a negative correlation between knowledge scores and attitude scores (r=-0.21, P<0.001). Additionally, healthcare workerspredominately used social media to inform themselves about COVID-19 (91.1%). Conclusions: The majority of healthcare workers had good knowledge and positive attitude toward COVID-19. However, the level of some knowledge and attitude lower than that expected for their position level towards the virus. Additional education interventions and campaigns are required for healthcare workers.

The potential efficacy of the E2-subunit vaccine to protect pigs against different genotypes of classical swine fever virus circulating in Vietnam

Polygonatum kingianum rhizome extract alleviates collagen antibody-induced arthritis by modulating proinflammatory cytokine production in mice

Objective: To evaluate the anti-arthritic effects of Polygonatum kingianum rhizome extract using both in vitro and in vivo models.Methods: Lipopolysaccharide-induced RAW 264.7 macrophages were treated with an ethanol extract of Polygonatum kingianum rhizomes at different concentrations to determine nitric oxide and prostaglandin E2 (PGE2) production. For in vivo study, Polygonatum kingianum ethanol extract was further investigated for its anti-inflammatory effect in a mouse model with collagen antibody-induced arthritis. Phytochemical study of Polygonatum kingianum ethanol extract was also performed. Results: Saponins (142 mg/g total yield) was the main component in the Polygonatum kingianum ethanol extract. 5α,8α-ergosterol peroxide, (E,E)-9-oxooctadeca-10,12-dienoic acid and 3-(2?-hydroxy-4?-methoxy-benzyl)-5,7-dihydroxy-8-methyl-chroman-4-one were isolated from the extract. Polygonatum kingianum ethanol extract exhibited potential anti-inflammatory effects by inhibiting nitric oxide and PGE2 production in RAW 264.7 cells in a dose-dependent manner. The level of arthritis in mice with collagen antibody-induced arthritis was significantly reduced (P<0.01) after treatment with Polygonatum kingianum ethanol extract, particularly at a dose of 1?000 mg/kg body weight. Besides, the extract demonstrated the regulatory effects on serum tumor necrosis factor-alpha, interleukin-6, and interleukin-10 in treated mice. Conclusions: Polygonatum kingianum ethanol extract has beneficial effects on inflammatory cytokine regulation and PGE2 inhibition in an experimental mouse model with collagen antibody-induced arthritis. The phytochemical screening reveals that the saponin, as the main component, and sterols (daucosterol and 5α,8α-ergosterol peroxide) from Polygonatum kingianum ethanol extract may contribute to its promising in vitro and in vivo anti-inflammatory activities.

Does conventional freezing affect sperm DNA fragmentation? / 대한생식의학회지

OBJECTIVE: Sperm cryopreservation has been widely used in assisted reproductive technology, as it offers great potential for the treatment of some types of male infertility. However, cryopreservation may result in changes in membrane lipid composition and acrosome status, as well as reductions in sperm motility and viability. This study aimed to evaluate sperm DNA fragmentation damage caused by conventional freezing using the sperm chromatin dispersion test. METHODS: In total, 120 fresh human semen samples were frozen by conventional methods, using SpermFreeze Solution as a cryoprotectant. Routine semen analysis and a Halosperm test (using the Halosperm kit) were performed on each sample before freezing and after thawing. Semen parameters and sperm DNA fragmentation were compared between these groups. RESULTS: There was a significant decrease in sperm progressive motility, viability, and normal morphology after conventional freezing (32.78%, 79.58%, and 3.87% vs. 16%, 55.99%, and 2.55%, respectively). The sperm head, midpiece, and tail defect rate increased slightly after freezing. Furthermore, the DNA fragmentation index (DFI) was significantly higher after thawing than before freezing (19.21% prior to freezing vs. 22.23% after thawing). Significant increases in the DFI after cryopreservation were observed in samples with both normal and abnormal motility and morphology, as well as in those with normal viability. CONCLUSION: Conventional freezing seems to damage some sperm parameters, in particular causing a reduction in sperm DNA integrity.

Antidiabetic and antioxidant activities of red seaweed Laurencia dendroidea

Objective: To investigate antidiabetic and antioxidant activities of the extract and fractions from Vietnamese red seaweed Laurencia dendroidea. Methods: The seaweed Laurencia dendroidea was extracted by using microwave-assisted extraction method in 80% methanol. The seaweed extract was then fractionated using different solvents (n-hexane, chloroform, ethyl acetate, butanol and water). These obtained fractions were evaluated for α -glucosidase inhibitory and antioxidant activities. Antioxidant activities were tested using DPPH, nitric oxide radical scavenging and metal chelating assays. The enzyme inhibition mode was determined using Lineweaver-Burk plot. For acidic and thermal stabilities, the ethyl acetate fraction was treated at pH 2.0 and 100 °C, respectively. The residual inhibitory activity of the fraction was calculated based on the initial inhibitory activity. For in vivo antidiabetic activity, mice were divided into four groups, including normal control, diabetic control, diabetic mice treated with ethyl acetate fraction and diabetic mice treated with gliclazide. Blood glucose level of treated mice during acute and prolonged treatments was measured. To evaluate the toxicity of the ethyl acetate fraction, the body weight changes and activities of liver function enzymes (aspartate transaminase, alanine transaminase and gamma-glutamyl transferase) were carried out. Results: The extract of Laurencia dendroidea showed strong α-glucosidase inhibitory and DPPH radical scavenging activities. Methanolic concentrations affected both α-glucosidase inhibitory and antioxidant activities. A 80% aqueous methanol was the suitable solvent for extraction of enzyme inhibitors and antioxidants. Among solvent fractions, ethyl acetate fraction had the highest inhibitory activities against α -glucosidase with a mixed type of inhibition and the strongest antioxidant activities, and was stable under acidic and thermal conditions. The ethyl acetate fraction treated diabetic mice significantly reduced blood glucose level compared with the diabetic control group (13.16 mmol/L vs. 22.75 mmol/L after 3 hours of treatment). Oral administration of ethyl acetate fraction did not exhibit toxicity at a dose of 100 mg/kg body weight as determined by body weight changes and liver biochemical parameters. Conclusions: Laurencia dendroidea could be a potential source for production of antidiabetic and antioxidative agents.