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 ℃, 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 gammaglutamyl 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.

Objective: To evaluate the anti-microsporidial effects of the active component of Nigella sativa seeds, thymoquinone, against Encephalitozoon intestinalis using an in vitro model. Methods: Anti-microsporidial effect of thymoquinone against Encephalitozoon intestinalis was evaluated by using various concentrations of thymoquinone (0, 1, 5, 10, 15, 20, 30, 35, and 40 μM) and sterile dimethyl sulfoxide. Real time PCR was used to evaluate the inhibitory effects of thymoquinone on the life cycle of Encephalitozoon intestinalis. Results: The cytotoxic effect of thymoquinone on HEK293 cell line was observed with 30, 35, and 40 μM concentrations of thymoquinone after 24, 48, and 72 hours of incubation. It was observed that 10, 15, 20, and 30 μM concentrations of thymoquinone decreased the spore density compared with the control; however, it was significant only at 30 μM. Conclusions: Thymoquinone shows potent anti-microsporidial effects against Encephalitozoon intestinalis in the in vitro model;however, the toxic concentrations of thymoquinone are also toxic to the host cells.

Objective: To evaluate a novel polyherbal formulation (BSVT) containing the standardized extracts from the leaves of Boerhavia diffusa, Solidago virgaurea, Vitex negundo, and thymoquinone in CCl4 induced hepatorenal toxicity in rats. Methods: A total of 36 rats were divided into six groups including normal control, CCl4 (2 mL/kg, i.p.), CCl4 (2 mL/kg, i.p.) + Cystone? (750 mg/kg p.o.), CCl4 (2 mL/kg, i.p.) + BSVT (25 mg/kg, p.o.), CCl4 (2 mL/kg, i.p.) + BSVT (50 mg/kg, p.o.), and CCl4 (2 mL/kg, i.p.) + BSVT (100 mg/kg, p.o.). All treatments were given for four weeks. Serum levels of aspartate transaminase, alanine transaminase, alkaline phosphatase, cholesterol, total protein, serum urea, blood urea nitrogen and creatinine were assessed. Superoxide dismutase, malondialdehyde, and glutathione peroxidase were evaluated in tissue homogenate. The histopathological study of liver and kidney tissues was also done. Results: Aspartate transaminase, alanine transaminase, alkaline phosphatase, cholesterol, serum urea, blood urea nitrogen and creatinine were significantly elevated (P<0.001) while total protein was considerably reduced in the CCl4 group as compared to the normal control (P<0.001), which indicated hepatorenal toxicity. In addition, superoxide dismutase and glutathione peroxidase activities were significantly decreased (P<0.001) while malondialdehyde levels were increased markedly (P<0.001). Treatment with BSVT formulation recovered these parameters towards a normal level in a dose-dependent manner. Conclusions: BSVT formulation ameliorates the hepatorenal toxicity in a dose-dependent manner. Furthermore, clinical studies are required to confirm its efficacy.

Objective: To investigate the anti-inflammatory properties of methanolic extract of Clausena excavata in lipopolysaccharide (LPS)-activated macrophages (J774A.1) and the effect on skin wound in a rat model through determining cytokine levels and gene expressions.Methods: The effects of methanolic extract of Clausena excavata on in vitro viability and TNF-α, IL-6, IL-10, and nitric oxide release by LPS-activated J774A.1 cells were determined. In addition, relative expressions of BAX, BCL-2 and COX-2 genes were examined in healed wounds of rats. Results: The methanolic extract of Clausena excavata was not toxic to J774A.1 cells at the highest dose of 400 μg/mL. It decreased levels of TNF-α and IL-6, while increasing IL-10 level in LPS-activated J774A.1 cells and in the healed wounds of rats. The methanolic extract of Clausena excavata also inhibited nitric oxide production in LPS-activated J774A.1 cells. The BAX and COX-2 genes were downregulated while the BCL-2 gene was upregulated in the healed wound of rats. Conclusions: The methanolic extract of Clausena excavata promotes wound healing via its anti-inflammatory and anti-apoptotic activities.

Objective: To compare limiting dilution assay and real-time PCR methods in Leishmania tropica parasite load measurement in vaccinated mice.Methods: BALB/c mice were vaccinated by Leishmania tropica soluble Leishmania antigen or recombinant Leishmania tropica stress-inducible protein-1 with/without adjuvant. After three vaccinations, mice were challenged by Leishmania tropica promastigotes. Two months after challenge, the draining lymph nodes of mice footpad were removed and parasite load was assayed by limiting dilution assay and real-time PCR methods. Limiting dilution assay was done by diluting tissue samples to extinction in a biphasic medium. For real-time PCR, DNA of the lymph nodes was extracted, equal dilutions of each sample were prepared and hot-start real-time PCR was done using appropriate primers. The data of the two methods were compared by appropriate statistical methods. Results: Both methods were able to measure different levels of parasite load in vaccinated/unvaccinated mice. In addition, wherever parasite load of a group was estimated high (or low) by one method, the estimated parasite load by another method was the same, although statistically significant differences were found between some groups. Conclusions: Both methods lead to approximately similar results in terms of differentiating parasite load of the experimental groups. However, due to the lower errors and faster process, the real-time PCR method is preferred.

Objective: To determine the new M-superfamily conotoxins from molluscivorous snail Conus bandanus in Vietnam. Methods: Conus bandanus venom was fractionated and purified on HPLC system with an analytical reversed-phase C18 column in order to screen small conotoxins. The primary structure of peptide was analyzed by matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry using collision-induced dissociation and confirmed by Edman's degradation method. Results: Five new conotoxins were biochemically characterized from the crude venom of the mollusk-hunting cone snail Conus bandanus, which were collected at Ke Ga reef of the Nha Trang Bay (Vietnam). Each conotoxin had 15 or 16 amino acid residues and shared the same characteristic cysteine framework V as -CC-C-C-CC-. They were termed as Bn3b, Bn3c, Bn3d, Bn3e and Bn3f following the conotoxins nomenclature. Conclusions: The conotoxins Bn3b, Bn3e, and Bn3f are categorized in the mini-M conotoxins of the M1 branch, while conotoxins Bn3c and Bn3d are categorized in the mini-M conotoxins of the M2 branch. The homological analysis reveals that these conotoxins could serve as promising probe compounds for voltage-gated sodium channels.

Objective: To investigate the wound-healing effect of Alocasia longiloba (A. longiloba) petiole extract on wounds in rats.Methods: Twenty-two male Sprague-dawley rats were randomly assigned to receive 10％ solcoseryl gel, phosphate buffer saline, 50％ ethanol, 95％ ethanol and hexane extracts of A. longiloba at 1.5％, 3％ and 6％ doses, respectively. A full thicknesses wound (6 mm) was created on the dorsal of the rat; and all rats were applied with the extract solutions, 10％ solcoseryl gel and phosphate buffer saline once a day topically until day 12. The wound was photographed on day 1, 6 and 12, and the percentage of wound contraction was calculated. On day 12, rats were sacrificed and histological examination of granulation tissue was carried out using haematoxylin & eosin and Masson's Trichrome stain to determine the wound healing effect.Results: In this study, 6％ of 50％ and 95％ ethanol extracts of A. longiloba showed 82.50％ and 82.32％ wound contraction, respectively, and were comparable with 10％ solcoseryl gel (82.30％). Meanwhile, phosphate buffer saline treated group showed the lowest wound contraction (69.86％). Histological assessment of wound treated with 6％ of 95％ ethanol extract of A. longiloba showed distinct epidermal and dermal layer, higher proliferation of fibroblast and more angiogenesis with collagen compared to other wound treated groups. Conclusions: A. longiloba petiole extracts have a wound healing potential and 6％ of 95％ ethanol extract of A. longiloba is more effective. Further studies are required to understand the wound healing mechanism of action of the extract.

Objective: To examine the effects of p-coumaric acid on ethanol-induced kidney injury in Swiss Wistar rats. Methods: Ethanol (25％ v/v) was used to induce nephrotoxicity in rats. p-Coumaric acid was orally administered at 50, 100, or 200 mg/kg body weight. The levels of oxidative parameters were determined; pro-inflammatory biomarkers were analyzed by Western blotting and apoptotic protein was analyzed by immunohistochemistry. Results: Ethanol treated rats showed decreased levels of antioxidants and aberrant production of pro-inflammatory cytokines (IL-6, IL1β, TNF-α), NF-κB activation and imbalance of pro-and anti-apoptotic proteins (Bcl-2, Bax, caspase 3). Meanwhile, p-coumaric acid restored antioxidant levels and decreased the levels of inflammatory cytokines, NF-κB, and pro-apoptotic proteins and increased Bcl-2 expression. Conclusions: p-Coumaric acid ameliorates ethanol-induced kidney injury by restoring antioxidant production and suppressing cellular apoptosis and inhibiting NF-κB expression. p-Coumaric acid should be further investigated as a promising candidate for ethanol-induced kidney toxicity.

Objective: To explore the protective effect of Polygonum minus ethanolic extract on cisplatin-induced neurotoxicity. Methods: In vitro test, total phenolic content assay and DPPH assay were performed to determine the antioxidant activity of Polygonum minus. For in vivo test, 30 male Sprague-Dawley rats were randomly divided into 5 groups: the control group, cisplatin 10 mg/kg, Polygonum minus 100 mg/kg, Polygonum minus 200 mg/kg and Polygonum minus 400 mg/kg. The control group and the cisplatin group were given distilled water whereas Polygonum minus groups received the respective dose of Polygonum minus extract orally for 14 d. On day 15, a single intraperitoneal administration of normal saline was given to the control group; while 10 mg/kg of cisplatin was given to the cisplatin group and Polygonum minus groups. Body weight, signs of illness, daily activity and mortality were observed at least once daily throughout the experimental period. On day 18, the anterior part of the brain was collected and processed for histological and ultrastructural analyses (right hemisphere). The remaining part (left hemisphere) of the brain was assayed to determine malondialdehyde and catalase levels for oxidative stress analyses. Results: Polygonum minus ethanolic extract possessed high phenolic content (977.6 mg GAE/g) and 95.9％ DPPH radical scavenging activities. No mortality was observed in all groups. Rats in the cisplatin group were weak and less active compared to Polygonum minus treated rats. In the cisplatin group, disorganised cellular layers of the cerebral cortex were observed whereas rats treated with low and mid doses of Polygonum minus extract had normal cerebral cortex as in the control group. Mild ultrastructural changes were observed in rats treated with low and mid doses of Polygonum minus extract. Meanwhile, low and mid doses of Polygonum minus extract significantly reduced malondialdehyde level whereas low and mid doses of Polygonum minus extracts groups significantly increased catalase activity compared to the cisplatin group. Conclusions: Polygonum minus ethanolic extract at 100 and 200 mg/kg attenuates cisplatin-induced oxidative stress in the cerebral cortex via its antioxidant activity.

Objective: To evaluate antibacterial activity and the bioactive compounds of 50％ hydro-ethanolic extract of Alpinia zerumbet (A. zerumbet) rhizomes. Methods: Eight reference microbial strains including two Gram-positive bacteria [Staphylococcus aureus (ATCC 29213) and Enterococcus faecalis (ATCC 29212)] and six Gram-negative bacteria [Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATTC 700603), Proteus mirabilis (DMST 8212), Salmonella enterica subsp. enterica serovar Vellore. (ATCC 15611), Shigella flexneri (ATCC 12022) and Pseudomonas aeruginosa (ATCC 27853)], were used to test antimicrobial susceptibility by the broth microdilution method. Bioactive compounds were analyzed by using HPLC. Results: The minimum inhibitory concentration values of A. zerumbet extract were 8 mg/mL for Staphylococcus aureus, Escherichia coli and Shigella flexneri and 16 mg/mL for Enterococcus faecalis and the other four Gram-negative bacilli. HPLC chromatograms revealed that the A. zerumbet extract contained hydroxybenzoic acids, hydroxycinnamic acids and flavonoids. Conclusions: The constituents of A. zerumbet rhizomes could be a potential source of antibacterial compounds, warranting further study of A. zerumbet extract.