Tyrosinase (TYR) is a type III copper oxidase present in fungi, plants and animals. The inhibitor of human TYR plays a vital role in pharmaceutical and cosmetic fields by preventing synthesis of melanin in the skin. To search for an effective TYR inhibitor from various plant extracts, a kinetic study of TYR inhibition was performed with mushroom TYR. Among Panax ginseng, Alpinia galanga, Vitis vinifera and Moringa oleifera, the extracts of V. vinifera seed, A. galanga rhizome and M. oleifera leaf reversibly inhibited TYR diphenolase activity with IC50 values of 94.8 ± 0.2 µg/mL, 105.4 ± 0.2 µg/mL and 121.3 ± 0.4 µg/mL, respectively. Under the same conditions, the IC50 values of the representative TYR inhibitors of ascorbic acid and kojic acid were found at 235.7 ± 1.0 and 192.3 ± 0.4 µg/mL, respectively. An inhibition kinetics study demonstrated mixed-type inhibition of TYR diphenolase by A. galanga and V. vinifera, whereas a rare uncompetitive inhibition pattern was found from M. oleifera with an inhibition constant of Kii 73 µg/mL. Phytochemical investigation by HPLC-MS proposed luteolin as a specific TYR diphenolase ES complex inhibitor, which was confirmed by the inhibition kinetics of luteolin. The results clearly showed that studying TYR inhibition kinetics with plant extract mixtures can be utilized for the screening of specific TYR inhibitors.

The current trend worldwide is searching plant extracts towards prevention of neurodegenerative disorders. This study aimed to investigate the neuroprotective effect of Alpinia galanga leaves (ALE), Alpinia galanga rhizomes (ARE), Vitis vinifera seeds (VSE), Moringa oleifera leaves (MLE), Panax ginseng leaves (PLE) and Panax ginseng rhizomes (PRE) ethanolic extracts on human neuroblastoma (SHSY5Y) cells. The 1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging of VSE and MLE were 81% and 58%, respectively. Ferric-reducing antioxidant power (FRAP) of ALE and MLE (33.57 ± 0.20 and 26.76 ± 0.30 μmol Fe(ΙΙ)/g dry wt., respectively) were higher than for the other extracts. Liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF/MS) revealed MLE active compounds. Intracellular study by nitro-blue tetrazolium (NBT) test showed that MLE and VSE had high O2− scavenging (0.83 ± 0.09 vs. 0.98 ± 0.08 mg/mL, respectively). MLE had the highest ROS scavenging followed by PRE (0.71 ± 0.08 vs. 0.83 ± 0.08 mg/mL, respectively), by 2,7-dichlorodihydrofluorescein diacetate (DCFHDA) assay. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity and neuroprotection tests on SHSY5Y showed that PRE had a better neuroprotective effect but higher cytotoxicity compared to MLE (viable cells 51% vs. 44%, IC50 1.92 ± 0.04 vs. 2.7 ± 0.2 mg/mL, respectively). In conclusion, among the studied plants, MLE has potential for developing as a neuroprotective agent.

Extraction of plant secondary metabolites were prepared and subjected as non-toxic, biodegradable and eco-friendly natural dyes. Two groups of cotton textiles were dyed with crude extracts of Curcuma longa and Hibiscus sabdariffa separately to examine and compare the staining ability of these extracts. Fabrics where treated with three different mordanting techniques using three different mordants which were copper, ferrous sulfates and potassium dichromate. Dyed fabrics were exposed to different conditions including washing with water and detergent as well as exposing to sun light in order to test the stability of the color. As a result Curcuma longa extract had higher potentially dying ability than Hibiscus sabdariffa extract, otherwise using of Potassium dichromate as a mordant gave best color stability compared with other used mordants, while dying of fabrics by premordanting method as exposing fabric samples to the mordants before dying with plant extracts showed the darker shade.

No abstract

Curcuma longa L., which belongs to the Zingiberaceae family, is a perennial herb distributed throughout tropical and subtropical regions of the world, being widely cultivated in Asiatic countries, Curcuminoids are inherent compounds of the species C. longa, there are three main compounds of this pigmented curcuminoid complex, namely, curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Curcumin is the major component of this plant, being responsible for the activities. Crude extract of Curcuma longa rhizomes was prepared by using ethanol and Chemical detection was performed in order to investigate the secondary metabolites compounds of ethanolic crude extract. Reversed high performance liquid chromatography carried out for the detection and estimation of curcumin in the crude extract. Otherwise cytogenetic study of the effect of C. longa crude extract and standard curcumin on the normal human lymphocyte blood cells done after exposure to nickel chloride (NiCl2), furthermore, karyotyping was performed by using MetasystemIkaros. Chemical detection of crude extract showed positive result for alkaloids, tannins, glycosides, phenols, Terpens, flavonoids, cumarines and resins while showed negative result for Saponins and Steroids. While the results of the cytogenetic study revealed that the effect of C. longa crude extract and standard curcumin reduced the genotoxic effect of nickel chloride (NiCl2) on the normal human lymphocyte blood cells. Karyotyping showed that genotoxic effect of nickel chloride appeared as aberration in chromosome number 18. While lymphocytes treated with C. longa crude extract or standard curcumin showed no chromosomal aberration, at the same time no chromosomal aberration were observed after treatment with combination of NiCl2 and crude extract or combination of NiCl2 and standard curcumin which indicated the ability of standard curcumin and C. longa crude extract to prevent the effect of nickel chloride. Further medical cytogenetic and molecular testing to get better understanding the protective role of Curcuma longa rhizomes, crude extract against heavy metal induced chromosomal aberrations in human blood cultures.

The development of functional food products is increasingly gaining lots of interest and popularity among stakeholders. The aim of this study was to evaluate the bioaccessibility of three Lactobacillus sp. starter cultures, including Lacticaseibacillus casei KKU-KK1, Lactiplantibacillus pentosus KKU-KK2, and Lactobacillus acidophilus KKU-KK3, in order to enhance the performance of the probiotic potential of Nham protein hydrolysates in Thai fermented sausage using microencapsulation technology. Probiotic microcapsules were created from a novel wall material made up of a combination of glutinous rice flour and inulin through a freeze-drying process. Accordingly, the results of three formulations of Nham probiotic and spontaneous fermentation (control) characterized by their physicochemical and microbiological characteristics displayed a correlation between an increase in the amount of total acidity, the population of lactic acid bacteria, and the generated TCA-soluble peptides, while the pH and total soluble protein gradually decreased under proteolysis during the fermentation time. The fractionation of Nham protein hydrolysates (NPHs) was prepared using a microwave extraction process: NPH-nham1, NPH-nham2, and NPH-nham3 (10 mg/mL with fermentation time 114 h), exhibited the highest DPPH radical-scavenging activity and FRAP-reducing power capacity as well, compared to NPH-nhamcontrol at p < 0.05. Moreover, those NPHs peptides showed dose-dependent inhibiting of selected pathogenic bacteria (E. coli TISTR 073, S. aureus TISTR 029, and Ent. aerogenes TISTR 1540). Anti-microbial properties of NPHs peptides against gram-negative bacteria were higher than against gram-positive bacteria. In conclusion, the bioaccessibility of NPHs peptides was significantly enhanced by micro-encapsulation and showed a potential bioactive characteristic for developing into a probiotic agent.

<abstract> <p>The demand for healthy food items with a high nutrient value of bioavailability and bioaccessibility has created a need for continuous development of technology and food ingredients like bioactive peptides. This study aimed to investigate seven proteolytic lactic acid bacteria (PLABs) isolated from the <italic>plaa-som</italic> (fermented fish) sample originated from silver BARB species for production of proteolytic enzymes. Proteolytic enzymes produced by (PLABs) were used further to create potent bioactive peptides by hydrolyzing proteins throughout PLAB-probiotics enhancer. Protein derived-bioactive peptides was tested the proteolytic activity on different protein sources and examined bioactivities including antioxidative and antimicrobial effect for further use in functional foods. Results of screened-PLAB strains showed high proteolytic activity namely <italic>Streptococcus thermophilus</italic> strains (KKUPA22 and KKUPK13). These strains have proteolytic system consisting of extracellular and cell-bound enzymes that used for degrading protein in fish flesh protein (FFP) and skim milk (SKM) broth media. Proteolytic activity of tested bacterial enzymes was estimated after incubation at 45, 37, and 50 °C. Furthermore, FFP hydrolysates were formed with various peptides and has small molecular weights (checked by SDS-PAGE) in the range of10.5 to 22 kDa), exhibiting strong activity. Data revealed that <italic>S. thermophilus</italic> strains (KKUPA22 and KKUPK13) had high antioxidant activity in term of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical-scavenging inhibition, and ferric reducing antioxidant power (FRAP) reducing power capacity. Both strains (KKUPA22 and KKUPK13) of <italic>S. thermophilus</italic> have higher antimicrobial activity against Gram-negative bacteria than against Gram-positive bacteria. We have confirmed presence of proteolytic (<italic>prt</italic>) gene regions in <italic>S. thermophilus</italic> strains using specific primers via PCR amplification. Results showed highest homology (100%) with the <italic>prt</italic>S gene of <italic>S. thermophillus</italic> located on the cell envelope proteolytic enzymes (CEPEs) such as serine proteinase. Therefore, it concluded that the proteolytic system of tested PLAB strains able to generate bioactive peptides-derived proteins having active biological property, good mechanism of degradability, and bioaccessibility for further use in catalyzing protein of functional foods.</p> </abstract>

Extraction of plant secondary metabolites were prepared and subjected as non-toxic, biodegradable and eco-friendly natural dyes. Two groups of cotton textiles were dyed with crude extracts of Curcuma longa and Hibiscus sabdariffa separately to examine and compare the staining ability of these extracts. Fabrics where treated with three different mordanting techniques using three different mordants which were copper, ferrous sulfates and potassium dichromate. Dyed fabrics were exposed to different conditions including washing with water and detergent as well as exposing to sun light in order to test the stability of the color. As a result Curcuma longa extract had higher potentially dying ability than Hibiscus sabdariffa extract, otherwise using of Potassium dichromate as a mordant gave best color stability compared with other used mordants, while dying of fabrics by pre-mordanting method as exposing fabric samples to the mordants before dying with plant extracts showed the darker shade.