Effect of feeding Aspergillus awamori and canola seed on the growth performance and muscle fatty acid profile in broiler chicken.

The aim of this study was to examine effects of dietary supplementation with Aspergillus awamori and feeding canola seed on the growth and fatty acid profile in broilers. Twenty-eight chicks (15 days old) were assigned to the following groups: (1) control, fed a basal diet; (2) awamori, fed the basal diet supplemented with 0.05% A. awamori; (3) canola, fed a diet containing 5% canola seed; and (4) canola + awamori, fed the canola diet supplemented with A. awamori (seven birds/group). Body weight gain was increased by A. awamori but not influenced by canola seed. Breast muscle weight was increased in either awamori or canola groups. Although plasma triglyceride and cholesterol were decreased by feeding A. awamori or canola seed, fat content in the breast muscle were increased, accompanied by decrease in saturated fatty acids and increase in unsaturated fatty acids. Moreover, decreased thiobarbituric acid reactive substance and increased α-tocopherol content in the breast muscle was observed in all experimental groups. In conclusion, these results suggested that feeding canola seed and A. awamori might improve growth performance, and modified muscle fatty acid profile and α-tocopherol content, suggesting that they may improve meat quality.

Aspergillus awamori feeding modifies lipid metabolism in rats.

In the present study, an experiment was conducted to show that A. awamori modifies lipid metabolism in mammals. A total number of 24 rats at 6 weeks of age were divided into 2 groups (10% and 30% fat dietary groups), and each group was further divided into control and experimental groups (6 rats per group). Rats in the experimental groups were given diets containing 0.05% A. awamori. The diets were administered for 3 weeks to evaluate the effects of A. awamori on growth, plasma lipid profile, and the expressions of genes related to lipid metabolism in the liver. After the rats were fed A. awamori, body weight gain was increased, while food intake was decreased; therefore, food efficiency was increased in both A. awamori groups. Plasma triglycerides, LDL cholesterol, and glucose levels were decreased, but plasma HDL cholesterol levels were increased. Furthermore, saturated fatty acids were decreased while; unsaturated fatty acids were increased in the liver. The liver mRNA levels of FAS, ACC, delta-6-desaturase, and HMG-CoA reductase were increased, while the mRNA level of LDL receptor was decreased. From these data, it is proposed that A. awamori could be used as an effective probiotic to prevent lifestyle-related diseases in humans.

Feeding Aspergillus awamori reduces skeletal muscle protein breakdown and stimulates growth in broilers.

This study was conducted to show that dietary supplementation of a fungus, Aspergillus awamori called Koji in Japan, reduces skeletal muscle protein breakdown and stimulates growth in broiler chickens. A total of 30 chicks at 15 days of age was divided into control and two treatment groups (10 birds per treatment). Control group was fed basal diet and treatment groups were fed the basal diets supplemented with A. awamori at levels of 0.05% and 0.2%. The birds were raised for 12 days from 15 to 27 days of age and then the effect on growth, organ weights and plasma 3-methylhistidine concentration and digestibilities of protein and energy was evaluated. The messenger RNAs (mRNAs) of atrogin-1, ubiquitin, proteasome, m-calpain, µ-calpain, ß-actin, myosin and pax-7 in the breast muscle were also measured. Body weight gain and breast muscle weight were increased, although feed intake was decreased by the fungus and thus feed efficiency was increased. Protein and energy digestibilities were increased. Furthermore, plasma 3-methylhistidine concentration was decreased by the fungus. The mRNAs of atrogin-1, ubiquitin, proteasome, m-calpain and µ-calpain were all decreased. The mRNA of ß-actin but not myosin and pax-7 was slightly increased by the fungus. In conclusion, feeding A. awamori improves growth performance because skeletal muscle proteolytic activity is reduced and digestibilities of energy and protein are increased.

The modification of the muscle fatty acid profile by dietary supplementation with Aspergillus awamori in broiler chickens.

The present study was conducted to show that dietary supplementation with a fungus, Aspergillus awamori, modifies muscle fatty acid profiles in broiler chickens. A total of thirty chicks, selected from a group of 100 chicks aged 15 d, were divided into a control group and two treatment groups (ten birds per treatment). The control group was fed a basal diet, and the treatment groups were fed basal diets supplemented with A. awamori at levels of 0·05 and 0·2 %. From the start of the study at 15 d, the birds were raised for an additional 12 d, and growth and the muscle fatty acid profile were evaluated. Although feed intake was decreased by the fungus, body-weight gain and breast muscle weight were increased, and thus, feed efficiency was improved. Abdominal fat and plasma cholesterol and TAG were decreased, while plasma HDL-cholesterol and breast muscle fat content were increased. Interestingly, muscle α-tocopherol content was increased and muscle thiobarbituric acid-reactive substances were decreased by A. awamori. Furthermore, there was an observed decrease in SFA and an increase in unsaturated fatty acids in the muscle fat due to the fungus feeding. The mRNA of fatty acid synthase, acetyl-CoA carboxylase and Δ-6 desaturase in the muscle were all increased, while the mRNA of 3-hydroxyl-3-methylglutaryl-CoA reductase and carnitine palmitoyl transferase 1A were decreased by the fungus. In conclusion, the present study clearly shows that the muscle lipid profile could be modified by the addition of A. awamori to the diet.

Contamination of rice by etofenprox, diethyl phthalate and alkylphenols: effects on first delivery and sperm count in mice.

We observed that first delivery was delayed when a group of paired mice fed with non-organic common rice compared to a group fed with organic rice. This led us to hypothesize that pesticides or other soil contaminants may be responsible for the effect on mice reproduction. We then found that the non-organic rice was contaminated with a pesticide etofenprox and nonylphenol, butylphenol and diethyl phthalate which are used as agricultural detergents or plasticizers of agricultural film, that are all suspected to be estrogenic. Therefore, the chemicals were administered to mice at the levels detected in rice, and we subsequently observed that first delivery and sperm count of the animals were significantly impaired. This study is the first to show that rice contaminated with agricultural chemicals affects reproduction in the mammal.

Effects of feeding hexane-extracts of a shochu distillery by-product on skeletal muscle protein degradation in broiler chicken.

We have found that shochu distillery by-product (SDBP) contains a growth promoting factor that can be extracted with ether. In the present study, we administered hexane-extracts of SDBP (HSDBP) to broiler chickens and observed changes in skeletal muscle protein degradation in order to clarify the mechanism of growth promotion due to SDBP feeding. The pectoralis superficial muscle weight was significantly increased by HSDBP feeding. Plasma N(tau)-methylhistidine concentration was significantly decreased by HSDBP, showing that the rate of muscle protein degradation decreased. It was also found that the expression of mRNA of ubiquitin-proteasome system and calpain was decreased by HSDBP. These results indicate that growth promotion due to SDBP is caused by suppression of skeletal muscle protein degradation, which is related to the ubiquitin-ptoteasome system and calpain.

Triiodothyronine but not thyroxine accelerates myofibrillar proteolysis via ATP production in cultured muscle cells.

These experiments were done to clarify that the differential effects of thyroxine (T(4)) and triiodothyronine (T(3)) on skeletal muscle protein turnover are caused by their roles on ATP production. Primary cultured chick muscle cells were treated with a physiological level of T(4) (60 ng/ml), T(3) (12 ng/ml), or ATP (0.5 mM) for 6 days and the protein content, ATP production, proteasome activity, and myofibrillar protein breakdown were measured. The protein content measured as an index of cell growth was not affected by T(4), T(3), or ATP. The cellular ATP level was increased by T(3) and ATP, but not by T(4). Proteasome activity and N(tau)-methylhistidine (MeHis) release measured as an index of myofiblillar protein breakdown was also increased by T(3) and ATP, but not by T(4). These results indicate that T(3) but not T(4) increases ATP production followed by an increase in proteasome activity, and thus stimulates myofibrillar proteolysis.

Effects of corticosterone on Ca2+ uptake and myofibrillar disassembly in primary muscle cell culture.

This study was done to examine the effects of corticosterone, a glucocorticoid, on Ca2+ uptake, proteolysis, and Ca2+ channels in primary cultures of chick muscle cells, to clarify the mechanism of glucocorticoid action on muscle proteolysis. Chick muscle cells were incubated for 24 h in a medium containing corticosterone (30 ng/ml) when the cells were confluent (6 days). To examine the contribution of Ca2+ channels, nifedipine, a Ca2+ channels antagonist, was used. Ca2+ uptake measured with 45CaCl2 was increased three-fold by corticosterone, with a peak at 12 h after the treatment started. The growth of the cells estimated from the protein content and creatine kinase activity was not affected by corticosterone. Proteolysis, evaluated with [3H]tyrosine as a label of the protein and Ntau-methylhistidine release, was unchanged by corticosterone. However, the amount of easily releasable myofilament as a measure of myofibrillar disassembly in the muscle cells was increased by corticosterone, and prevented by nifedipine. These results show that corticosterone increases Ca2+ uptake and starts myofibrillar protein breakdown.

Effects of the thyroid hormone on differentiation, growth, and proteolysis in cultured muscle cells during serum deprivation.

The actions of the thyroid hormone (T3) are modified by other hormones. Therefore, in the normal cell culture system, with serum as a medium ingredient, it is difficult to eliminate the influences of other hormones derived from the serum. In the present study, two experiments were conducted to clarify the effects of T3 on differentiation, growth and proteolysis (experiment 1), and concerted effects of T3 and insulin (experiment 2) in a serum-free culture with the use of muscle cells originated from chick embryo. Protein content and creatine kinase (CK) activity were examined as indices of growth and differentiation of the muscle cells, respectively, and N(tau)-methylhistidine (MeHis) release was examined as an index of myofibrillar proteolysis. It was observed that T3 suppressed both the muscle differentiation and proteolysis in the serum-free medium (experiment 1), though in our previous experiment they were enhanced by T3 in the serum-supplemented normal medium. On the other hand, T3 increased myofibrillar proteolysis and had no effect on muscle differentiation when insulin was included in the serum-free medium (experiment 2). These results clearly show that the effects of thyroid hormones on muscle differentiation and proteolysis are apparently different when serum is deprived from the medium, and these differential effects of thyroid hormone could be partially explained by an interaction with insulin, one of the growth factors in the serum.