Fermented Supernatants of Lactobacillus plantarum GKM3 and Bifidobacterium lactis GKK2 Protect against Protein Glycation and Inhibit Glycated Protein Ligation.

With age, protein glycation in organisms increases continuously. Evidence from many studies shows that the accumulation of glycated protein is highly correlated with biological aging and the development of aging-related diseases, so developing a dietary agent to attenuate protein glycation is very meaningful. Previous studies have indicated that lactic acid bacteria-fermented products have diverse biological activities especially in anti-aging, so this study was aimed to investigate the inhibitory effect of the fermented supernatants of Lactobacillus plantarum GKM3 (GKM3) and Bifidobacterium lactis GKK2 (GKK2) on protein glycation. The results show that GKM3- and GKK2-fermented supernatants can significantly inhibit protein glycation by capturing a glycation agent (methylglyoxal) and/or protecting functional groups in protein against methylglyoxal-induced responses. GKM3- and GKK2-fermented supernatants can also significantly inhibit the binding of glycated proteins to the receptor for advanced glycation end products (RAGE). In conclusion, lactic acid bacteria fermentation products have the potential to attenuate biological aging by inhibiting protein glycation.

Lactobacillus plantarum GKM3 Promotes Longevity, Memory Retention, and Reduces Brain Oxidation Stress in SAMP8 Mice.

(1) Background: An age-related cognitive decline is commonly affecting the life of elderly with symptoms involved in progressive impairments to memory and learning. It has been proposed that probiotics could modulate age-related neurological disorders via the gut-brain axis. (2) Methods: To investigate the anti-aging effect of probiotic Lactobacillus plantarum GKM3, both survival tests and cognitive experiments were conducted in the SAMP8 mice model. The six-month-old SAMP8 (n = 20 in each gender) were fed with probiotic GKM3 at a dosage of 5.1 × 109 and 1.0 × 109 cfu/ kg B.W./day until their natural death. Then, the life span was investigated. Three-month-old SAMP8 (n = 10 in each gender) were administered GKM3 for 14 weeks. Then, the behavior tests and oxidation parameters were recorded. (3) Results: GKM3 groups showed significantly increased latency in the passive avoidance test and time of successful avoidance in the active avoidance test. The TBARS and 8-OHdG from mice brains also showed a significant reduction in the groups treated with GKM3. In addition, lower accumulation of the amyloid-ß protein was found in SAMP8 mice brains with the supplement of GKM3. (4) Conclusions: These results indicated that L. plantarum GKM3 delayed the process of aging, alleviated age-related cognitive impairment, and reduced oxidative stress.

An Examination of Lactobacillus paracasei GKS6 and Bifidobacterium lactis GKK2 Isolated from Infant Feces in an Aged Mouse Model.

Supplementary which could maintain normal physiological mechanisms and functions while aging has drawn our attention due to the population aging in recent years. Probiotics have been believed with desirable properties such as antioxidation and anti-inflammatory for delaying the aging process. However, the age-related experiments conducted in the mammalian models with probiotics were few. In this study, we demonstrated the effects of administration of probiotics Lactobacillus paracasei GKS6 (GKS6) and Bifidobacterium lactis GKK2 (GKK2), respectively, at the dosage of 5.0 × 109 cfu/kg BW/day for fourteen weeks in senescence-accelerated mouse prone 8 (SAMP8) mice. The three-month-old SAMP8 mice were divided into three groups: control, mice fed with GKS6, and mice fed with GKK2. There were ten females and ten males in each group. The SAMP8 mice fed with probiotics GKS6 and GKK2 showed a significantly lower degree of aging followed by Takeda's grading method on the eleventh week of the experiment. The GKK2 group showed significantly increased forelimb grip strength in male SAMP8 mice and muscle fiber number in both genders. Compared to the control, both GKS6 and GKK2 presented a significant increase in liver superoxide dismutase and catalase activities. In addition, a significant decrease in the levels of liver thiobarbituric acid-reactive substances was observed in the probiotics group. These results suggested that probiotics GKS6 and GKK2 could act as antioxidants in delaying the process of aging and preventing age-related muscle loss.

Protective effects of Lactobacillus plantarum against chronic alcohol-induced liver injury in the murine model.

Long-term alcohol consumption causes liver injuries such as alcoholic hepatitis, fatty liver, and endotoxemia. Some probiotics were demonstrated to exert beneficial effects in the gastrointestinal tract. The present study was aimed to evaluate the protective effects of Lactobacillus plantarum CMU995 against alcohol-induced liver injury. The mice were orally administered L. plantarum CMU995 for 1 week, followed by the administration of alcohol and different tested substances daily for 6 weeks. The liver injury was examined by measuring the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA), anti-oxidative enzyme, endotoxin, inflammatory cytokines, and lipid accumulation in the liver or serum among different groups. L. plantarum CMU995 exhibited beneficial effects on alcohol-induced liver injury via reduction in the serum concentration of AST, ALT, cholesterol, triglycerides, endotoxin, TNF-α, IL-1ß, and oxidative stress. Furthermore, we also found that the levels of glutathione (GSH), superoxide dismutase (SOD), and intestinal tight junction protein zonula occludens-1 (ZO-1) were considerably higher in L. plantarum CMU995-fed groups when compared with placebo group. Meanwhile, the protective effects were demonstrated biological gradients as controversial dose-dependent. We speculate that L. plantarum CMU995 inhibited the migration of alcohol-derived endotoxin into the blood and liver, thereby improving the intestinal barrier. The present evidence may provide a novel microbiota-based strategy to prevent the alcohol-induced liver injury.

Fermented soymilk and soy and cow milk mixture, supplemented with orange peel fiber or Tremella flava fermented powder as prebiotics for high exopolysaccharide-producing Lactobacillus pentosus SLC 13.

BACKGROUND: A high exopolysaccharide-producing Lactobacillus pentosus SLC 13 strain was isolated from mustard pickles and showed the characteristics of a probiotic. Orange peel fiber powder (OPFP) and Tremella flava fermented powder (TFP) were shown to be potential prebiotics for L. pentosus SLC 13. The present study aimed to further develop new symbiotic fermented lactic acid beverages using SLC 13 with different proportions of cow milk and soymilk as food substrates, as well as with OPFP or TFP as prebiotics. RESULTS: Acidification rate (soymilk groups, 3.02-4.37 mU min-1 ; soymilk/milk mixture groups, 1.33-2.84 mU min-1 ) and fermentation time (soymilk groups, 7.09-9.25 h; soymilk/milk mixture groups, 12.51-27.34 h) indicated that soymilk represents a suitable substrate for SLC 13-mediated fermentation. Moreover, OPFP and TFP induced a higher exopolysaccharide production of SLC 13 and a higher water holding capacity of fermented beverages. Sensory evaluations suggested that soymilk groups fermented with 10 g kg-1 OPFP (SF-1.0P) and that with 5 g kg-1 TFP (SF-0.5T) and also soymilk/milk mixture groups fermented with 5 g kg-1 OPFP (HSMF-0.5P) and that with 10 g kg-1 TFP (HSMF-1.0T) represent potential fermented drinks. Additionally, SF-1.0P and SF-0.5T products could be preserved for at least 21 days at 4 °C, with high viable cell counts (> 8.8 log10 CFU mL-1 ) and water holding capacity. CONCLUSION: In the present study, we developed SF-1.0P and SF-0.5T products as a new symbiotic fermented lactic acid beverages. However, in the future, consumer acceptability could be improved by properly regulating the ratio of sugar to acid or seasoning. © 2019 Society of Chemical Industry.

Rapidly detecting major peanut allergen-Ara h2 in edible oils using a new immunomagnetic nanoparticle-based lateral flow assay.

Ara h2 is a major peanut allergen that induces rashes, vomiting, diarrhea, and anaphylactic shock. Since peanut is a major source in producing edible oils globally, Ara h2 residues can be present in various edible oils. In this work, an immunomagnetic nanoparticle-based lateral flow assay for identifying Ara h2 in edible oils is developed. This assay exhibits high sensitivity with a visual detection limit of 0.1 mg/kg Ara h2 in oil, and favorable specificity in differentiating peanut from seeds and nuts. The calculated CV values of intra- and inter-assay were 6.73-10.21% and 4.75-8.57%, respectively, indicating high reproducibility. In an analysis of 26 oil products, Ara h2 was detected in two peanut oils as 0.122 ±â€¯0.026 mg/kg and 0.247 ±â€¯0.027 mg/kg. The entire method takes 5 h, including a 3.5-h sample preparation. Hence, this method has the potential to be an effective way to screen edible oils for Ara h2.

Strategic ultrasound-induced stress response of lactic acid bacteria on enhancement of ß-glucosidase activity for bioconversion of isoflavones in soymilk.

The purpose of the study is to develop the new methodology of strategic ultrasound treatment on lactic acid bacteria (LAB) to induce stress response for the enhancement of ß-glucosidase activity that can be used for the biotransformation of glucosides into aglycones isoflavones in soymilk. Among the five LAB tested, Lactobacillus acidophilus BCRC 10695 showed the best ability to release ß-glucosidase for further ultrasonic stimulation to induce proper stress response. With ultrasound (20 kHz, amplitude at 20%) to irradiate on L. acidophilus BCRC 10695 at stationary phase of growth for 2 min and 24 h of re-incubation, the ß-glucosidase activity was enhanced to 3.91 U/ml, which was 1.82 times of that without ultrasound treatment. Using the ultrasound-treated L. acidophilus BCRC 10695 to ferment soymilk, the fraction of aglycones in total isoflavones in soymilk was effectively increased from 21.8% initially to 97.9% in 24 h. The strategic ultrasound treatment on L. acidophilus BCRC 10695 demonstrated promotion of ß-glucosidase activity, and this methodology had the potential to be applied in the production of functional soymilk by adding probiotics LAB to increase the bioactive isoflavones and nutritional values for human health.

Complete genome sequence of Lactobacillus pentosus SLC13, isolated from mustard pickles, a potential probiotic strain with antimicrobial activity against foodborne pathogenic microorganisms.

BACKGROUND: Lactobacillus pentosus SLC13 is a high exopolysaccharide (EPS)-producing strain with broad-spectrum antimicrobial activity and the ability to grow in simulated gastrointestinal conditions. SLC13 was isolated from mustard pickles in Taiwan for potential probiotic applications. To better understand the molecular base for its antimicrobial activity and high EPS production, entire genome of SLC13 was determined by PacBio SMRT sequencing. RESULTS: L. pentosus SLC13 contains a genome with a 3,520,510-bp chromosome and a 62,498-bp plasmid. GC content of the complete genome was 46.5% and that of plasmid pSLC13 was 41.3%. Sequences were annotated at the RAST prokaryotic genome annotation server, and the results showed that the genome contained 3172 coding sequences and 82 RNA genes. Seventy-six protein-coding sequences were identified on the plasmid pSLC13. A plantaricin gene cluster, which is responsible for bacteriosins biosynthesis and could be associated with its broad-spectrum antimicrobial activity, was identified based on comparative genomic analysis. Two gene clusters involved in EPS production were also identified. CONCLUSION: This genomic sequence might contribute to a future application of this strain as probiotic in productive livestock potentially inhibiting competing and pathogenic organisms.

Characterization of high exopolysaccharide-producing Lactobacillus strains isolated from mustard pickles for potential probiotic applications.

The aim of this study was to characterize high exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) isolated from mustard pickles in Taiwan for potential probiotic applications. Among 39 collected LAB strains, four most productive EPS-producing strains were selected for further analysis. Comparative analyses of 16S rDNA genes rpoA and pheS sequences demonstrated that these strains were members of Lactobacillus plantarum-group (LPG). NCD 2, NLD 4, SLC 13, and NLD 16 showed survival rates of 95.83% ± 0.49%, 95.07% ± 0.64%, 105.84% ± 0.82%, and 99.65% ± 0.31% under simulated gastrointestinal conditions, respectively. No cytotoxic effects on macrophage RAW 264.7 cells were observed when they were treated with a low dose (1 µg/ml) of stimulants extracted from the tested LAB strains. The production of nitric oxide in RAW 264.7 cells incubated with various LAB stimulants showed a dose-dependent increase. Among the four strains, SLC 13 showed higher inhibitory activity on growth of Enterococcus faecalis (BCRC 12302) and Yersinia enterocolitica (BCRC 10807). NLD 4 showed strong inhibitory activity against Escherichia coli O157:H7 (ATCC 43894) as compared with the other three strains. In summary, our results suggest that Lactobacillus pentosus SLC 13 may be a good candidate for probiotic applications and for development of antibacterial compounds. [Int Microbiol 20(2):75-84 (2017)].

Characterization of high exopolysaccharideproducing Lactobacillus strains isolated from mustard pickles for potential probiotic applications

The aim of this study was to characterize high exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) isolated from mustard pickles in República de China for potential probiotic applications. Among 39 collected LAB strains, four most productive EPS-producing strains were selected for further analysis. Comparative analyses of 16S rDNA genes rpoA and pheS sequences demonstrated that these strains were members of Lactobacillus plantarum-group (LPG). NCD 2, NLD 4, SLC 13, and NLD 16 showed survival rates of 95.83% ± 0.49%, 95.07% ± 0.64%, 105.84% ± 0.82%, and 99.65% ± 0.31% under simulated gastrointestinal conditions, respectively. No cytotoxic effects on macrophage RAW 264.7 cells were observed when they were treated with a low dose (1 μg/ml) of stimulants extracted from the tested LAB strains. The production of nitric oxide in RAW 264.7 cells incubated with various LAB stimulants showed a dose-dependent increase. Among the four strains, SLC 13 showed higher inhibitory activity on growth of Enterococcus faecalis (BCRC 12302) and Yersinia enterocolitica (BCRC 10807). NLD 4 showed strong inhibitory activity against Escherichia coli O157:H7 (ATCC 43894) as compared with the other three strains. In summary, our results suggest that Lactobacillus pentosus SLC 13 may be a good candidate for probiotic applications and for development of antibacterial compounds (AU)

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Combination of ultrasonic irradiation with ionic liquid pretreatment for enzymatic hydrolysis of rice straw.

The application of ultrasonic irradiation and ionic liquids (ILs) in the degradation of rice straw under different processes of pretreatment and enzymatic hydrolysis was investigated. Various substrates for enzymatic hydrolysis by cellulase with and without ultrasound were as follows: untreated rice-straw powder (RS); RS treated by ILs of 1-ethyl-3-methylimidazolium ethylsulfate and trihexyl (tetradecyl) phosphonium decanoate with ultrasound at 300 W/(40 kHz, 28 kHz); RS treated by IL of choline hydroxide ([Ch][OH]) with ultrasound at 300 W/40 kHz (CHRS). In ultrasound-mediated enzymatic hydrolysis, the yield of total reducing sugar (TRS) converted from CHRS was up to 96.22% at 240 min and was greater than that from the other substrates; the TRS yield for CHRS with ultrasound was 19.5% greater than that without irradiation. Lignocellulosic biomass pretreated with [Ch][OH] showed the highest efficiency among the tested ILs, and ultrasound can be applied effectively in rice-straw pretreatment and enzymatic hydrolysis.

Effects of fermentation on antioxidant properties and phytochemical composition of soy germ.

BACKGROUND: Traditional soy-fermented foods, such as miso, douche, natto, and tempeh have been widely used as a dietary supplement in Asian countries, and numerous reports on their phenolics and antioxidant activities have been published. Soy germ contains 10-fold higher phenolics than whole soybean, hence using soy germ as fermentation substrate will be more efficient than whole soybean. RESULTS: Soy germ fermented with Aspergillus niger M46 resulted in a high-efficiency bio-transformation of phenolics and flavonoids to their metabolites, and a diverse secondary metabolic product was also found to response oxidation stress of fungal colonisation. Its antioxidant activity against hydroxyl radicals and superoxide radicals (IC50 = 0.8 and 6.15 µg mL(-1) , respectively) was about 205-fold and 47-fold higher than those of unfermented soy germ (IC50 = 164.0 and 290.48 µg mL(-1) ), respectively. These results were similar to those observed for Trolox, and more active than those of BHT and hesperidin. The ß-glucosidase and α-amylase produced during fermentation were mainly responsible for mobilisation of the phenolics. CONCLUSION: Our results demonstrate that fermented soy germ has the potential to be a good dietary supplement for prevention of oxidative stress-related diseases, and the solid-state bioprocessing strategy could be an innovative approach to enhance the antioxidant activity of soy germ.

Microbiological quality of chicken- and pork-based street-vended foods from Taichung, Taiwan, and Laguna, Philippines.

The microbiological quality of chicken- and pork-based street-food samples from Taichung, Taiwan's night markets (50) and Laguna, Philippines' public places (69) was evaluated in comparison to a microbiological guideline for ready-to-eat foods. Different bacterial contamination patterns were observed between 'hot-grilled' and 'cold cooked/fried' food types from the two sampling locations with 'hot grilled' foods generally showing better microbiological quality. Several samples were found to be unsatisfactory due to high levels of aerobic plate count, coliform, Escherichia coli, and Staphylococcus aureus. The highest counts obtained were 8.2 log cfu g⁻¹, 5.4 log cfu g⁻¹, 4.4 log cfu g⁻¹, and 3.9 log cfu g⁻¹, respectively, suggesting poor food hygiene practices and poor sanitation. Salmonella was found in 8% and 7% of Taichung and Laguna samples, respectively, which made the samples potentially hazardous. None of the samples was found to be positive for Listeria monocytogenes and E. coli O157, but Bacillus cereus was detected at the unsatisfactory level of 4 log cfu g⁻¹ in one Laguna sample. Antimicrobial resistance was observed for Salmonella, E. coli, and S. aureus isolates. Food preparation, cooking, and food handling practices were considered to be contributors to the unacceptable microbiological quality of the street foods. Hence, providing training on food hygiene for the street vendors should result in the improvement of the microbiological quality of street foods. The data obtained in this study can be used as input to microbial risk assessments and in identifying science-based interventions to control the hazards.

The applications of polysaccharides from various mushroom wastes as prebiotics in different systems.

The bases or stipes of mushrooms are normally discarded as low-economic value animal feed and compost. There are no known reports on deriving polysaccharides from these mushroom wastes for use as prebiotics. This study showed that the relatively low concentration (0.1% to 0.5%) of polysaccharides from Lentinula edodes stipe, Pleurotus eryngii base, and Flammulina velutipes base can enhance the survival rate of Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium longum subsp. longum during cold storage. The polysaccharides had synergistic effects with the peptides and amino acids from a yogurt culture to maintain probiotics above 10(7) CFU/mL during cold storage, and they also had significant protective effects on these probiotics in simulated gastric and bile juice conditions to achieve beneficial effects in the host. These results showed that mushroom wastes, which are cheaper than other sources, could be an important, new, alternative source of prebiotics.

Fermentation of rice hull by Aspergillus japonicus under ultrasonic pretreatment.

The application of ultrasound for treating rice hull used as the fermentation substrate for xylooligosaccharides production was investigated. Aspergillus japonicus CY6-1 was selected to produce cellulolytic and xylanolytic enzymes from untreated rice hull (RH) and rice hull treated with ultrasound (USRH-M). The hemicellulose yield was increased to 1.4-fold with ultrasound, and treatment time was greatly shortened from 24h to 1.5h at 80 °C and 300 W/28 kHz. The morphology of RH from various pretreatments was observed with field emission scanning electron microscope (FESEM), revealing the surface structure of USRH-M smoother than that of RH. USRH-M was much easier to be utilized by fungi, to extend the stability of enzyme activity and to increase activities of CMCase, ß-glucosidase, and xylanase compared with those of untreated RH. The final fermentative products were xylotetraose, xylohexaose, and higher molecular weight xylooligosaccharides, achieving xylohexaose yield for USRH-M 80% higher than that for RH group.

Immunomodulatory activities and antioxidant properties of polysaccharides from Monascus-fermented products in vitro.

BACKGROUND: Monascus-fermented products have featured in Chinese cuisine for thousands of years and are widely used as food colourants and dietary materials in many Asian countries. Rice and dioscorea fermented with Monascus purpureus NTU 568 have health-promoting attributes in vitro and in vivo. The aim of this study was to investigate the immunomodulatory and antioxidant effects of polysaccharides from red mould rice (RMRP) and red mould dioscorea (RMDP) in Raw 264.7 cells. RESULTS: The results showed the antioxidant capabilities (including scavenging, chelating, inhibition of lipid peroxidation, and reducing power) of RMRP and RMDP at a concentration of 10 mg mL(-1). RMRP and RMDP also stimulated cell proliferation, nitric oxide production, phagocytosis and cytokine production (including IL1-ß, IL-6 and TNF-α) in Raw 264.7 cells. CONCLUSION: These findings demonstrate that RMRP and RMDP have antioxidant and immunomodulation potential to be developed as novel dietary supplements.

Purification and properties of a novel phenolic antioxidant from Radix astragali fermented by Aspergillus oryzae M29.

The Chinese herb Radix astragalus (RA) has been widely used as a dietary supplement in Asia, and there are numerous reports on its bioactivities. However, there are no reports to date regarding the use of Aspergillus spp. in the culture medium of the RA plant for the production of phenolic antioxidants. In this study, utilizing the fungus Aspergillus to ferment the native RA has successfully resulted in a significant increase in the phenolic contents of RA, and the fermented RA also revealed much better antioxidant activity toward 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals, hydroxyl radical, superoxide radical and peroxyl radical than those of unfermented RA. Among these phenolics, a potent novel antioxidant was isolated and identified as 3,4-di(4'-hydroxyphenyl) isobutyric acid with a molecular weight of 272, by ESI-MS (electrospray ionization mass), ¹H NMR (nuclear magnetic resonance), ¹³C NMR, DEPT (distortionless enhancement by polarization transfer)-NMR, HMQC (heteronuclear multiple quantum coherence), and HMBC (heteronuclear multiple bond correlation) spectra. These data demonstrated that the solid-state bioprocessing strategy could be an innovative approach to enhance the antioxidant activity of RA.

Adherent properties and macrophage activation ability of 3 strains of lactic acid bacteria.

Lactic acid bacteria (LAB) must possess probiotic properties in order to be beneficial to humans and animals. The adherent properties, the acid and bile tolerance as well as the macrophage activation ability of isolated LAB strains were investigated in this study. The adhesion was analyzed following heat, acid, trypsin, and sodium periodate treatments. Production of the cytokine tumor necrosis factor-α (TNF-α) by RAW 264.7 macrophages was also measured after stimulation with heat-killed LAB strains. The viable strains of Lactobacillus fermentum AF7, L. acidophilus GG5, and L. plantarum BB9 were able to tightly adhere to the intestinal Caco-2 cells. In addition, the GG5 strain was not affected by heating, acid, trypsin, or sodium periodate treatment. However, the adhesion of strains AF7 and BB9 was reduced significantly by heating and trypsin treatment. This result suggested the GG5 and AF7 or BB9 strains had different cell-surface adherent factors. TNF-α production by the RAW 264.7 macrophages was induced significantly following stimulation with heat-killed LAB at 10(8) CFU/mL in a dose-dependent fashion. In addition, macrophage activity was similar whether the treatment consisted of live probiotics, or probiotics treated with heat, acid, or trypsin. However, the activity was reduced after treating with sonication. These in vitro results showed that the LAB studied possess probiotic characteristics, such as acid or bile tolerance, adherent capability, and immune activation, and may suggest that these LAB strains retain their probiotic activity as they pass through the gastrointestinal tract.

Anti-Helicobacter pylori activity of fermented milk with lactic acid bacteria.

BACKGROUND: Ten strains of lactic acid bacteria (LAB) were investigated for their anti-Helicobacter pylori effects. The bactericidal activity and organic acid content in spent culture supernatants (SCS) from fermented milk were measured. In addition, the exclusion effect of SCS against H. pylori infection of human gastric epithelial AGS cells was assayed. RESULTS: Three LAB strains, LY1, LY5 and IF22, showed better anti-Helicobacter effects than the other strains. There were no significant differences in the bactericidal activity of LAB strains between original SCS, artificial SCS and SCS treated by heating or protease digestion. However, neutralised SCS lost this activity. These results suggest that the anti-H. pylori activity of SCS may be related to the concentration of organic acids and the pH value but not to protein components. In the AGS cell culture test, both fermented LY5-SCS and artificial LY5-SCS significantly reduced H. pylori infection and urease activity (P < 0.05). CONCLUSION: In this study, in vitro methods were used to screen potential probiotics with anti-H. pylori activity. This may provide an excellent and rapid system for studying probiotics in the functional food and dairy industries.

The impact of transgenic papaya (TPY10-4) fruit supplementation on immune responses in ovalbumin-sensitised mice.

BACKGROUND: A transgenic papaya line (TPY10-4) that is resistant to both papaya ringspot virus (PRSV) and papaya leaf distortion mosaic virus (PLDMV) has been developed in Taiwan. This study investigated the immunomodulatory properties of transgenic TPY10-4 and its native (TCK) papaya fruits using an ovalbumin (OVA)-sensitised mouse model. Both green and ripe papaya fruits at low (0.2 g powder kg(-1) body weight (BW)) and high (1.6 g powder kg(-1) BW) doses were administered to experimental mice by intragastric gavage for 5 weeks. Changes in serum total immunoglobulin A (IgA), IgE, IgG and IgM levels, OVA-specific IgE, IgG1 and IgG2a titres and Th1/Th2 cytokine secretions using splenocytes were determined. RESULTS: Transgenic TPY10-4 or native TCK papaya fruit supplementation did not significantly affect body, visceral organ and relative tissue weights, total IgE antibody levels, OVA-specific IgE and IgG1 antibody titres or OVA-stimulated interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4, IL-5 and IL-10 secretions using splenocytes. However, transgenic papaya fruits markedly increased serum total IgM levels. CONCLUSION: This study suggests that transgenic TPY10-4 papaya fruits do not increase the allergenic potential of OVA by oral administration but may have a protective immunity via increasing the serum total IgM level.