Potato (Solanum tuberosum L. cv. Gogu valley) protein as an antimicrobial agent in the diets of broilers.

Two experiments were conducted to evaluate potato protein (PP, experiment 1) and refined PP (RPP, experiment 2) obtained from Gogu valley tubers as an antimicrobial agent in broiler diets. In both the experiments, 1-d-old male Ross 308 chicks were allotted to 5 treatments and performance, nutrient retention, and microbial populations in excreta and cecum were studied. Dietary treatments were as follows: basal diet (negative control, NC), basal diet with antibiotic (positive control, PC, 10 mg/kg of avilamycin), and low, medium, or high levels of PP (0.25, 0.50, and 0.75%, respectively, in experiment 1) or RPP (200, 400, and 600 mg/kg, respectively, in experiment 2). The overall gain and retention of DM (d 20 to 21) and CP (d 20 to 21 and d 41 to 42) were greater in birds fed PC and high PP diets than birds fed the NC diet. Population of total aerobic bacteria and coliforms was lowest in the cecum and excreta of birds fed the PC diet and highest in birds fed the NC diet. An increase in dietary PP linearly improved BW gain, feed intake, and feed conversion ratio during starter phase and overall BW gain. Also, there was linear improvement in retention of DM (d 20 to 21) and CP (d 20 to 21 and d 41 to 42) and reduced populations of total aerobic bacteria and coliforms in the cecum (d 42) and excreta (d 28 and 42) due to an increase in dietary PP. In the second experiment, the PC diet and diets with increasing levels of RPP had no effect on performance and nutrient retention. Birds fed the PC diet had the lowest microbial population in excreta and cecum, whereas the population of total aerobic bacteria and coliforms in excreta and cecum decreased (linear, P < 0.05) as the level of RPP was increased in the diet. These results suggest that both PP and RPP obtained from Gogu valley potato tubers have in vivo antimicrobial activity.

Potato (Solanum tuberosum L. cv. Gogu valley) protein as a novel antimicrobial agent in weanling pigs.

A total of 280 weaned pigs (Landrace x Yorkshire x Duroc) were used in a 28-d growth study to investigate the effect of feeding different levels of potato proteins on growth performance, nutrient digestibility, immune response, small intestinal morphology, and bacterial populations in feces and large intestine. Pigs (initially 6.42 +/- 0.74 kg of BW and 23 +/- 3 d of age) were randomly allotted to 5 treatments on the basis of BW, each treatment composed of 4 pens, each pen having 14 pigs. Dietary treatments included positive control (PC; basal diet + 150 mg/kg apramycin and 10 mg/ kg colistin sulfate); and potato protein (PP), consisting of the basal diet with 0, 0.25, 0.50, or 0.75% of potato protein. Diets were fed in 2 phases: phase I (d 0 to 14 postweaning) and phase 2 (d 14 to 28 postweaning). Potato protein was extracted from a value-added type of the new potato variety, Solanum tuberosum L. cv. Gogu valley, and was shown to have a minimum inhibitory concentration of 300 to 500 mug/mL. Performance of PC was compared with 0.25 to 0.75% PP, whereas linear and quadratic trends of increasing PP (0 to 0.75% PP) were tested. Over the 28-d trial, pigs fed the PC diets showed improved overall ADG (P < 0.05) and G:F (P = 0.090) compared with pigs fed PP, whereas increasing levels of PP linearly improved ADG (P < 0.05), ADFI (P = 0.052), and G:F (P = 0.098). The digestibility of DM and CP in both the phases was greater in PC than PP, and feeding of PP linearly improved the DM digestibility (P < 0.05) in phase II. The bacterial populations in the feces of pigs fed PC and PP were comparable, except for total bacteria and coliform bacteria in the feces at d 14 and 28, which were decreased in PC; and feeding of PP was effective in linearly reducing the populations of microbes in feces and contents of cecum, colon, and rectum. There was linear increase (P < 0.10) in skin-fold thickness in response to phytohemagglutinin with an increase in PP levels. Haemagglutinin titers on d 21 were greater (P = 0.054) in PC, and at d 28 the haemagglutinin titers were quadratically affected in pigs fed PP (P = 0.070). There was a trend toward a decrease in crypt depth (P = 0.068) and a greater villus height:crypt depth ratio (P = 0.082) of ileum in PC compared with PP. These results suggest that PP may be an alternative to medicated feed with antibiotics because it showed antimicrobial activity by effectively reducing the population of coliform bacteria and also improved the performance of weanling pigs.

Augmentation of macrophage functions by an aqueous extract isolated from Platycodon grandiflorum.

Platycodon grandiflorum has been claimed to have a wide range of health benefits, which include immunostimulation and antitumor activity. The associated biological mechanisms are unclear; however, of the wide diversity of effects, it is believed that their activities may be exerted through several potent effector cells such as macrophages. Therefore, the effects of an aqueous extract from the root of P. grandiflorum (Changkil: CK) on mouse peritoneal macrophage function were investigated. It was found that CK stimulated macrophage proliferation, spreading ability, phagocytosis, cytostatic activity, and nitric oxide production in a dose-dependent manner, and that the production of cytokines such as TNF-alpha, IL-1beta and IL-6 were similarly increased. CK significantly affected secretion at concentrations greater than 10 microg/ml; its maximal effects were at the concentration of 100 microg/ml. Reverse transcription-polymerase chain reaction showed that CK increased the appropriate cytokine mRNAs. These results suggest that CK is a potent enhancer of macrophage function.

Isolation and characterization of a novel antifungal peptide from Aspergillus niger.

A novel antifungal peptide (termed as Anafp) was isolated from the culture supernatant of the filamentous fungi, Aspergillus niger. The whole amino acid sequence of Anafp was determined and the peptide was found to be composed of a single polypeptide chain with 58 amino acids including six cysteine residues. The peptide shows some degree of sequence homology to a cysteine-rich antifungal peptides reported from the seeds of Sinapis alba and Arabidopsis thaliana or the extracellular media of Aspergillus giganteus and Penicillium chrysogenumsome. Cysteine-spacing pattern of Anafp was similar to that of the antifungal peptide from Penicillium chrysogenum. The Anafp exhibited potent growth inhibitory activities against yeast strains as well as filamentous fungi at a range from 4 to 15 microM. In contrast, Anafp did not show antibacterial activity against Escherichia coli and Bacillus subtilis even at 50 microM.

Identification and partial purification of pollen allergens from Artemisia princeps.

The pollen of Artemisia has been considered as the main late summer-autumn allergen source in this country. To identify its allergenic components, Artemisia princeps pollen extracts were separated by 10% sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), and transferred to nitrocellulose membrane, where IgE binding components were detected by the reaction with sera of twenty Artemisia-allergic patients and 125I-anti-human IgE, sixteen components in the molecular range of 10,000 and 85,000 daltons were detected. Twelve bands bound to IgE from 50% of the sera tested, and two bands (37,000, 23,000 daltons) showed the highest (85%) frequency of IgE-binding in twenty sera tested. When the gel of SDS-PAGE with Artemisia pollen extracts was sliced into 11 allergenic groups (AG) and the protein of each AG was obtained by the gel elution method, the wormwool-RAST inhibition test showed that the AG 10 demonstrated to be the most potent, and the AG 7 was the next. Six AGs showed significant responses (more than 100% of wheal size to histamine, 1 mg/ml) on the skin prick test in more than 50% of the patients tested. It is suggested that electrophoretic transfer analysis with SDS-PAGE may be a valuable method for Artemisia allergen identification, and the possibility of partial purification of allergens by employing gel elution is discussed.