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Importance of amino acid composition to improve skin collagen protein synthesis rates in UV-irradiated mice.

Murakami H, Shimbo K, Inoue Y, Takino Y, Kobayashi H - Amino Acids (2011)

Bottom Line: The FSR of dermal tropocollagen was measured 30 min after a single oral administration of amino acids (1 g/kg) to groups of 5-16 UVB-irradiated mice.Branched-chain amino acids (BCAA, 1.34±0.32), arginine (Arg, 1.66±0.39), glutamine (Gln, 1.75±0.60), and proline (Pro, 1.48±0.26) did not increase the FSR of skin tropocollagen compared with distilled water, which was used as a control (1.56±0.30).However, essential amino acids mixtures (BCAA+Arg+Gln, BCAA+Gln, and BCAA+Pro) significantly increased the FSR (2.07±0.58, 2.04±0.54, 2.01±0.50 and 2.07±0.59, respectively).

View Article: PubMed Central - PubMed

Affiliation: Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, 1-1 Suzuki-cho, Kawasaki, 210-8681, Japan. hitoshi_murakami@ajinomoto.com

ABSTRACT
Skin collagen metabolism abnormalities induced by ultraviolet (UV) radiation are the major causes of skin photoaging. It has been shown that the one-time exposure of UV irradiation decreases procollagen mRNA expression in dermis and that chronic UV irradiation decreases collagen amounts and induces wrinkle formation. Amino acids are generally known to regulate protein metabolism. Therefore, we investigated the effects of UV irradiation and various orally administered amino acids on skin collagen synthesis rates. Groups of 4-5 male, 8-week-old HR-1 hairless mice were irradiated with UVB (66 mJ/cm2) twice every other day, then fasted for 16 h. The fractional synthesis rate (FSR; %/h) of skin tropocollagen was evaluated by incorporating L-[ring-2H5]-phenylalanine. We confirmed that the FSR of dermal tropocollagen decreased after UVB irradiation. The FSR of dermal tropocollagen was measured 30 min after a single oral administration of amino acids (1 g/kg) to groups of 5-16 UVB-irradiated mice. Branched-chain amino acids (BCAA, 1.34±0.32), arginine (Arg, 1.66±0.39), glutamine (Gln, 1.75±0.60), and proline (Pro, 1.48±0.26) did not increase the FSR of skin tropocollagen compared with distilled water, which was used as a control (1.56±0.30). However, essential amino acids mixtures (BCAA+Arg+Gln, BCAA+Gln, and BCAA+Pro) significantly increased the FSR (2.07±0.58, 2.04±0.54, 2.01±0.50 and 2.07±0.59, respectively). This result suggests that combinations of BCAA and glutamine or proline are important for restoring dermal collagen protein synthesis impaired by UV irradiation.

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Plasma insulin concentrations 30 min after oral amino acids administration to UVB-irradiated mice. Arg + Gln (RQ) significantly increased plasma insulin concentrations 30 min after oral administration. However, there was no correlation between plasma insulin concentration and the FSR of skin tropocollagen. We postulate that BCAA + Arg + Gln (BCAARQ), BCAA + Gln (BCAAQ), BCAA + Pro (BCAAP), and the essential amino acids mixture (EAA) increased the FSR of skin tropocollagen independently of insulin. Values are presented as means ± SD. Comparisons with the control group (DW distilled water) were conducted with a Dunnett’s test after ANOVA for multiple comparison (*P < 0.05)
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Fig5: Plasma insulin concentrations 30 min after oral amino acids administration to UVB-irradiated mice. Arg + Gln (RQ) significantly increased plasma insulin concentrations 30 min after oral administration. However, there was no correlation between plasma insulin concentration and the FSR of skin tropocollagen. We postulate that BCAA + Arg + Gln (BCAARQ), BCAA + Gln (BCAAQ), BCAA + Pro (BCAAP), and the essential amino acids mixture (EAA) increased the FSR of skin tropocollagen independently of insulin. Values are presented as means ± SD. Comparisons with the control group (DW distilled water) were conducted with a Dunnett’s test after ANOVA for multiple comparison (*P < 0.05)

Mentions: Plasma insulin concentrations 30 min after oral amino acid administration are shown in Fig. 5. Arg + Gln significantly increased plasma insulin concentrations compared to the DW group (1.14 ± 0.61 vs. 0.56 ± 0.6 nag/ml). However, there was no correlation between plasma insulin concentration and the FSR of skin tropocollagen (r2 = 0.0049; Fig. 6).Fig. 5


Importance of amino acid composition to improve skin collagen protein synthesis rates in UV-irradiated mice.

Murakami H, Shimbo K, Inoue Y, Takino Y, Kobayashi H - Amino Acids (2011)

Plasma insulin concentrations 30 min after oral amino acids administration to UVB-irradiated mice. Arg + Gln (RQ) significantly increased plasma insulin concentrations 30 min after oral administration. However, there was no correlation between plasma insulin concentration and the FSR of skin tropocollagen. We postulate that BCAA + Arg + Gln (BCAARQ), BCAA + Gln (BCAAQ), BCAA + Pro (BCAAP), and the essential amino acids mixture (EAA) increased the FSR of skin tropocollagen independently of insulin. Values are presented as means ± SD. Comparisons with the control group (DW distilled water) were conducted with a Dunnett’s test after ANOVA for multiple comparison (*P < 0.05)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3351609&req=5

Fig5: Plasma insulin concentrations 30 min after oral amino acids administration to UVB-irradiated mice. Arg + Gln (RQ) significantly increased plasma insulin concentrations 30 min after oral administration. However, there was no correlation between plasma insulin concentration and the FSR of skin tropocollagen. We postulate that BCAA + Arg + Gln (BCAARQ), BCAA + Gln (BCAAQ), BCAA + Pro (BCAAP), and the essential amino acids mixture (EAA) increased the FSR of skin tropocollagen independently of insulin. Values are presented as means ± SD. Comparisons with the control group (DW distilled water) were conducted with a Dunnett’s test after ANOVA for multiple comparison (*P < 0.05)
Mentions: Plasma insulin concentrations 30 min after oral amino acid administration are shown in Fig. 5. Arg + Gln significantly increased plasma insulin concentrations compared to the DW group (1.14 ± 0.61 vs. 0.56 ± 0.6 nag/ml). However, there was no correlation between plasma insulin concentration and the FSR of skin tropocollagen (r2 = 0.0049; Fig. 6).Fig. 5

Bottom Line: The FSR of dermal tropocollagen was measured 30 min after a single oral administration of amino acids (1 g/kg) to groups of 5-16 UVB-irradiated mice.Branched-chain amino acids (BCAA, 1.34±0.32), arginine (Arg, 1.66±0.39), glutamine (Gln, 1.75±0.60), and proline (Pro, 1.48±0.26) did not increase the FSR of skin tropocollagen compared with distilled water, which was used as a control (1.56±0.30).However, essential amino acids mixtures (BCAA+Arg+Gln, BCAA+Gln, and BCAA+Pro) significantly increased the FSR (2.07±0.58, 2.04±0.54, 2.01±0.50 and 2.07±0.59, respectively).

View Article: PubMed Central - PubMed

Affiliation: Frontier Research Laboratories, Institute for Innovation, Ajinomoto Co., Inc, 1-1 Suzuki-cho, Kawasaki, 210-8681, Japan. hitoshi_murakami@ajinomoto.com

ABSTRACT
Skin collagen metabolism abnormalities induced by ultraviolet (UV) radiation are the major causes of skin photoaging. It has been shown that the one-time exposure of UV irradiation decreases procollagen mRNA expression in dermis and that chronic UV irradiation decreases collagen amounts and induces wrinkle formation. Amino acids are generally known to regulate protein metabolism. Therefore, we investigated the effects of UV irradiation and various orally administered amino acids on skin collagen synthesis rates. Groups of 4-5 male, 8-week-old HR-1 hairless mice were irradiated with UVB (66 mJ/cm2) twice every other day, then fasted for 16 h. The fractional synthesis rate (FSR; %/h) of skin tropocollagen was evaluated by incorporating L-[ring-2H5]-phenylalanine. We confirmed that the FSR of dermal tropocollagen decreased after UVB irradiation. The FSR of dermal tropocollagen was measured 30 min after a single oral administration of amino acids (1 g/kg) to groups of 5-16 UVB-irradiated mice. Branched-chain amino acids (BCAA, 1.34±0.32), arginine (Arg, 1.66±0.39), glutamine (Gln, 1.75±0.60), and proline (Pro, 1.48±0.26) did not increase the FSR of skin tropocollagen compared with distilled water, which was used as a control (1.56±0.30). However, essential amino acids mixtures (BCAA+Arg+Gln, BCAA+Gln, and BCAA+Pro) significantly increased the FSR (2.07±0.58, 2.04±0.54, 2.01±0.50 and 2.07±0.59, respectively). This result suggests that combinations of BCAA and glutamine or proline are important for restoring dermal collagen protein synthesis impaired by UV irradiation.

Show MeSH
Related in: MedlinePlus