Enzyme‐Treated Asparagus Extract Promotes Expression of Heat Shock Protein and Exerts Antistress Effects

Abstract

A novel enzyme-treated asparagus extract (ETAS) has been developed as a functional material produced from asparagus stem. Studies were conducted to determine the effect of ETAS on heat shock protein 70 (HSP70) expression and alleviation of stress. HeLa cells were treated with ETAS, and HSP70 mRNA and protein levels were measured using a reverse transcription-polymerase chain reaction (RT-PCR) assay and an enzyme-linked immunosorbent assay (ELISA), respectively. ETAS showed significant increases in HSP70 mRNA at more than 0.125 mg/mL and the protein at more than 1.0 mg/mL. The antistress effect was evaluated in a murine sleep-deprivation model. A sleep-deprivation stress load resulted in elevation of blood corticosterone and lipid peroxide concentrations, while supplementation with ETAS at 200 and 1000 mg/kg body weight was associated with significantly reduced levels of both stress markers, which were in the normal range. The HSP70 protein expression level in mice subjected to sleep-deprivation stress and supplemented with ETAS was significantly enhanced in stomach, liver, and kidney, compared to ETAS-untreated mice. A preliminary and small-sized human study was conducted among healthy volunteers consuming up to 150 mg/d of ETAS daily for 7 d. The mRNA expression of HSP70 in peripheral leukocytes was significantly elevated at intakes of 100 or 150 mg/d, compared to their baseline levels. Since HSP70 is known to be a stress-related protein and its induction leads to cytoprotection, the present results suggest that ETAS might exert antistress effects under stressful conditions, resulting from enhancement of HSP70 expression.

Effects of Enzyme-Treated Asparagus Extract on Heat Shock Protein 70, Stress Indices, and Sleep in Healthy Adult Men

“…In an animal study, we found that ETAS suppressed blood corticosterone elevation, as well as up-regulated HSP70 protein levels of the stomach, liver and kidney, in mice subjected to sleep deprivation when given ETAS (15). Other investigators have reported that ETAS shows neuroprotective effects in vitro and attenuates cognitive impairment in senescence-accelerated mice (17).…”

“…Since the previous study revealed that ETAS significantly increased HSP70 expression level in mice and humans (15), a bigger sample size might be necessary for the current detection procedure. ETAS improved several parameters of the autonomic nervous system (ANS) condition.…”

“…Previous studies demonstrated that a methanolic extract of asparagus seeds regulates blood glucose levels in diabetic rats (13), and the young shoots and the leaves of asparagus alleviate liver cell toxicity induced by ethanol (14). We have developed a new functional material, enzyme-treated asparagus extract (ETAS), from unused stems of asparagus grown in Hokkaido, and observed that ETAS enhances the expressions of HSP70 mRNA and protein in HeLa cells, a human cervical adenocarcinoma cell line (15). From our other study, it was revealed that ETAS contains 5-hydroxymethyl-2-furfural and its derivative, which is a novel compound and named asfural (Fig.…”

Enzyme-Treated Asparagus Extract Attenuates Hydrogen Peroxide-Induced Matrix Metalloproteinase-9 Expression in Murine Skin Fibroblast L929 Cells

“…A human study also demonstrated that serum and salivary cortisol levels in subjects receiving ETAS were lower than those in the placebo group [2]. These anti-stress effects of ETAS are associated with the induction of molecular chaperones such as heat shock protein 70 [1][2][3].…”

“…Growing evidence indicates that enzyme-treated asparagus extract (ETAS) from the unused bottom parts of asparagus (Asparagus officinalis) exhibits a wide variety of beneficial biological actions. For example, intake of ETAS attenuates the elevation of plasma corticosterone levels in sleep-deprived mice [1]. A human study also demonstrated that serum and salivary cortisol levels in subjects receiving ETAS were lower than those in the placebo group [2].…”