Roasted Barley Extract (Mugi-cha) Containing Cyclo(d‑Phe‑l‑Pro) Prevents Lowering
of the Cutaneous Blood Flow and Skin Temperature under Air Conditioning:
A Randomized, Double-Blind, Placebo-Controlled, Crossover Study
posted on 2018-05-24, 00:00authored byHiroshi Ashigai, Mai Mizutani, Yoshimasa Taniguchi, Yasuko Matsukura, Keiko Nakashima, Emiko Ikeshima, Hiroaki Yajima
Roasted barley extract (RBE), also
known as mugi-cha, is a well-known
healthy non-caffeinated beverage, and its health functionality has
been widely reported. Our previous clinical study showed that RBE
affects the cutaneous blood flow and skin temperature after cold-water
immersion and that cyclo(d-Phe-l-Pro) is responsible
for its effect. In this study, we investigated whether cyclo(d-Phe-l-Pro)-containing RBE prevents the decrease in the
cutaneous blood flow and skin temperature. Subjects remained in the
air-conditioned room while ingesting RBE or a placebo. We measured
the cutaneous blood flow and skin temperature. We evaluated the effect
of RBE administration by two-way repeated measures analysis of variance.
A total of 15 subjects were enrolled. The change in cutaneous blood
flow in the RBE and placebo groups was −0.79 ± 0.38 and
−2.03 ± 0.35 mL min–1 100 g–1, respectively (p value of 0.041). The change in
the skin temperature in the RBE and placebo groups was −1.85
± 0.35 and −3.02 ± 0.30 °C, respectively (p value of <0.001). We also did subclass analysis with
cold-feeling subjects. For the seven subjects who had cold sensation,
the change in the cutaneous blood flow in the RBE and placebo groups
was −0.48 ± 0.58 and −2.56 ± 0.48 mL min–1 100 g–1, respectively (p value of 0.008). The change in the skin temperature in
the RBE and placebo groups was −1.46 ± 0.74 and −2.89
± 0.39 °C, respectively (p value of 0.009).
Thus, RBE containing cyclo(d-Phe-l-Pro) prevents
the decrease in the cutaneous blood flow and skin temperature under
air conditioning.