Jakkapan Sirithunyalug

Effect of pH on complex formation between debranched waxy rice starch and fatty acids

Complex formations between debranched waxy rice starch (DBS) and fatty acids (FA) of different hydrocarbon chain lengths (8:0, 10:0, 12:0, 14:0, 16:0, and 18:0) were studied in an aqueous solution by measuring the blue colour stained with iodine. The objective of this study was to understand the effects of the solubility and hydrophobicity of guest molecules (FA) on the complex formation with DBS. Lauric acid (12:0) displayed the greatest complex forming ability with DBS by showing the least blue colour developed with iodine. The effect of pH (3-7) on the DBS/FA complex formation was evaluated by measuring the iodine-scanning spectra of the mixture. Short-chain FA (8:0) displayed less complex formation at pH>or=5, above the pK(a) of fatty acid (approximately 4.8), which suggested that the charge formation of the short-chain FA caused a lower partitioning of the FA into the hydrophobic cavity of the DBS single helix. On the contrary, FA of 10:0-18:0 displayed an increased complex formation at pH>5, which could be attributed to increased solubility of these longer-chain FA at a dissociated and ionized form. The hydrocarbon chain length of the FA had an important impact on the extent of the complex formation. A FA that had a shorter hydrocarbon chain was more soluble in an aqueous solution and more readily formed a complex with DBS. At pH 6 and 7 (above the pK(a)), 10:0 formed less inclusion complexes with DBS than did 12:0. Iodine-scanning spectra showed that the absorbances of all iodine-stained DBS/FA solutions at higher wavelength were substantially lower than that of the iodine-stained DBS alone, suggesting that FA preferentially formed inclusion complexes with DBS of longer chains.

Antibacterial Activity and Inhibition of Adherence of Streptococcus mutans by Propolis Electrospun Fibers

Mouth-dissolving fibers with antibacterial activity for the oral cavity were prepared by an electrospinning technique. Propolis extract was used as an active ingredient and polyvinylpyrrolidone (PVP) K90 as the polymer matrix. The morphology and diameter of the fibers were characterized by scanning electron microscopy. Antibacterial activity against Streptococcus mutans and the inhibition of S. mutans adhesion on a smooth glass surface during the biofilm formation were tested. Propolis, 5% (w/v), was combined with a PVP K90 solution, 8% (w/v), with or without Tween 80 including flavor additives and electrospun with an applied voltage of 15 kV. Uniform and smooth fibers of propolis-PVP K90 were obtained. The results showed that electrospun fibers with propolis extract can dissolve and release the propolis in water. Propolis-PVP electrospun fibers showed better antibacterial activity by reduction of bacteria adhesion on a smooth glass surface when compared to some commercial mouthwash products. These results indicated the potential of electrospun fibers to be used as mouth-dissolving fibers for effective antibacterial activity in the oral cavity.

Preparation of glutinous rice starch/polyvinyl alcohol copolymer electrospun fibers for using as a drug delivery carrier

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Preparation of glutinous rice starch nanofibers by electrospinning

Glutinous rice starch (GRS) is produced from glutinous rice which is commonly cultivated in the Northeast of Thailand. GRS contains two types of glucose polymers which are amylose and amylopectin. Glutinous rice starch nanofibers (GNF) can be produced by an electrospinning technique. This is not a complicated method but needs a high voltage power supply. The aim of this study was to understand the production of GNF and physical-chemical properties of GNF. The morphology of GNF was examined by scanning electron microscopy. The characteristics of GNF are high porosity, flake multi-layers and a high swelling power. The Electrospinning technique did not change the chemical structure of GRS based on an FT-IR evaluation. This research revealed the basic characteristics of electrospun glutinous starch for use in various applications in the future.

Effect of Aromatic Substitution of Curcumin Nanoformulations on Their Stability

Curcumin, a poorly water-soluble bioactive compound, was successfully loaded into three different aromatic contents of hydroxypropylmethacrylamide (HPMA)-based polymeric micelles in order to develop water-soluble curcumin nanoformulations (Cur-Nano). The stability study of Cur-Nano was done by keeping the formulations at 4, 30, and 40 °C for 90 days. The physical appearance, curcumin remaining, and particle size of Cur-Nano were examined by visual inspection, high-performance liquid chromatography, and dynamic light scattering, respectively. After the storage period, the Cur-Nano composed of 100% aromatic-substituted polymer exhibited the highest stability of curcumin (80% of curcumin remaining) with a similar particle size as measured on the first day (50–60 nm) in all storage conditions. Curcumin in Cur-Nano composed of 25% and 0% aromatic-substituted polymer was significantly less stable accordingly. The results suggested that aromatic substitution to HPMA-based polymeric micelles can significantly enhance the stability of the loaded curcumin, considerably due to the π-π stacking interactions between the aromatic groups of curcumin and the polymer. It is concluded that curcumin-loaded polymeric micelles with high substituted aromatic content can be promising candidates with good storage stability for further clinical evaluations.

Development of Colorectal-Targeted Dietary Supplement Tablets Containing Natural Purple Rice Bran Oil as a Colorectal Chemopreventive

Colorectal cancer occurs due to various factors. The important risks are dietary lifestyle and inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis. It has been found that the inhibitory enzyme cyclooxygenase-2 (COX-2) in the colorectal region can potentially reduce the risk of colorectal cancer. The present study investigated rice bran oil from natural purple rice bran, which exhibits antioxidant and anti-inflammatory activity. This study aimed to evaluate the bioactive compound content of natural purple rice bran oil (NPRBO) derived from native Thai purple rice and the anti-inflammatory activity of NPRBO in colorectal cancer cells, and to develop a colorectal delivery platform in the form of film-coated tablets. NPRBO from the rice bran of five different Thai purple rice cultivars, namely Khao’ Gam Leum-Phua (KGLP), Khao’ Gam Boung (KGB), Khao’ Gam Thor (KGT), Khao’ Gam Pah E-Kaw (KGPEK), and Khao’ Niaw Dam (KND), were extracted using the supercritical carbon dioxide extraction technique. The amount of γ-oryzanol (ORY), tocotrienols, and tocopherols present in NPRBOs and the in vitro anti-inflammatory activity of NPRBO were investigated. The highest anti-inflammatory NPRBO was transformed into a dry and free-flowing powder by liquisolid techniques. Then, it was compressed into core tablets and coated with Eudragit®L100 and Eudragit® NE30D. The in vitro release study of the film-coated NPRBO tablets was performed in three-phase simulated gastrointestinal media. The cultivar KGLP was superior to the other samples in terms of the ORY, tocotrienol and tocopherol contents and anti-inflammatory activity. Aerosil® was the most suitable absorbent for transforming NPRBO into a free-flowing powder and was used to prepare the NPRBO core tablets. The in vitro KGLP-NPRBO film-coated tablet release profile showed that no ORY was released at gastric pH while 85% of ORY was released at pH 7.4 after 6 h; this would be expected to occur in the colorectal area. Therefore, this study demonstrates the potential of KGLP-NPRBO to prevent colorectal cancer via a specific colorectal dietary supplement delivery system.

Effect of synbiotics on caecal morphology and lesion score in broilers infected with Eimeria tenella.

The extensive use of the anti-coccidial drugs for prevention and control of coccidiosis in poultry has been a major factor in the success of the industry. The aim of this study was to investigate the influence of a synbiotic which combined between 106cfu/mL of Lactobacillus plantalum CMU-FP002, and 2% Shallot extract v/v mix in water on Eimeria tenella infections in broiler chickens. One hundred and thirty-five day-old male broiler chicks were randomly assigned to three cages with three replications per treatment, with treatment groups including: (1) No synbiotic feeding to a non-infected, group; (2) no synbiotic feeding to chicks infected with 20,000 Eimeria tenella sporulated oocysts; and (3) synbiotic feeding to chicks infected with 20,000 Eimeria tenella sporulated oocysts. Lesion scores were assessed by gross pathological examination based on a scale of 0-4 at 0, 3, 6, 9, and 12 days post infection. Untreated broilers infected with E. tenella were found to have highly damaged caeca (P<0.05) at days 6 and 12, whereas broilers infected with E. tenella but treated with the synbiotic also had damaged caeca, but with less damage than infected broilers fed no synbiotic. Broilers fed the synbiotic were also found to have altered epithelial morphology, but less so than the non-treated group. These results indicate that synbiotics may have a preventative effect on coccidiosis in broilers, but do not fully protect against the negative impact of the infection.