Fermented Oyster Extract Attenuated Dexamethasone-Induced Muscle Atrophy by Decreasing Oxidative Stress

Abstract

It is well known that oxidative stress induces muscle atrophy, which decreases with the activation of Nrf2/HO-1. Fermented oyster extracts (FO), rich in γ-aminobutyric acid (GABA) and lactate, have shown antioxidative effects. We evaluated whether FO decreased oxidative stress by upregulating Nrf2/HO-1 and whether it decreased NF-κB, leading to decreased IL-6 and TNF-α. Decreased oxidative stress led to the downregulation of Cbl-b ubiquitin ligase, which increased IGF-1 and decreased FoxO3, atrogin1, and Murf1, and eventually decreased muscle atrophy in dexamethasone (Dexa)-induced muscle atrophy animal model. For four weeks, mice were orally administered with FO, GABA, lactate, or GABA+Lactate, and then Dexa was subcutaneously injected for ten days. During Dexa injection period, FO, GABA, lactate, or GABA+Lactate were also administered, and grip strength test and muscle harvesting were performed on the day of the last Dexa injection. We compared the attenuation effect of FO with GABA, lactate, and GABA+lactate treatment. Nrf2 and HO-1 expressions were increased by Dexa but decreased by FO; SOD activity and glutathione levels were decreased by Dexa but increased by FO; NADPH oxidase activity was increased by Dexa but decreased by FO; NF-κB, IL-6, and TNF-α activities were increased by Dexa were decreased by FO; Cbl-b expression was increased by Dexa but restored by FO; IGF-1 expression was decreased by Dexa but increased by FO; FoxO3, Atrogin-1, and MuRF1 expressions were increased by Dexa but decreased by FO. The gastrocnemius thickness and weight were decreased by Dexa but increased by FO. The cross-sectional area of muscle fiber and grip strength were decreased by Dexa but increased by FO. In conclusion, FO decreased Dexa-induced oxidative stress through the upregulation of Nrf2/HO-1. Decreased oxidative stress led to decreased Cbl-b, FoxO3, atrogin1, and MuRF1, which attenuated muscle atrophy.

Effect of Fermented Sarco Oyster (Crassostrea gigas) Extract on Muscle Strength Enhancement in Postmenopausal Females: A Randomized, Double-Blind, Placebo-Controlled Trial

“…The placebo capsule was identical to the FSO capsule in appearance and was filled with dextrin. In a previous animal study, no toxicity was observed with 100 mg/kg and 200 mg/kg admission of FSO for 28 days [ 14 ]. Therefore, a safe and effective dose of 200 mg/kg was converted to the dose appropriate for a 60 kg adult human based on the body surface area and was calculated as 960 mg/day.…”

Exercise intervention mitigates zebrafish age‐related sarcopenia via alleviating mitochondrial dysfunction

“…For example, ROS have been demonstrated to promote muscle atrophy by activating the ubiquitin‐proteasome pathway [23]. The pathological changes in skeletal muscle atrophy can be prevented by decreasing ROS production [24]. Dihydroethidium staining showed that the ROS content was significantly increased in the skeletal muscle of the MA group compared to that in the CON group, whereas exercise significantly decreased the high ROS levels associated with aging (Fig.…”

Effect of fermented oyster (Crassostrea gigas) extracts and regular walking on muscle strength and mass in older adults with relatively low muscle mass: A randomized controlled trial

“…The placebo was identical to the FO capsule in appearance and was filled with corn starch. Based on the results of a previous animal study, which showed that the minimum efficacious and safe dose of FO was 200 mg/kg ( 10 ), the dose used in the animal subjects was converted to a human equivalent dose based on the person’s body surface area, i.e., 960 mg for individuals weighing 60 kg. In addition, a previous preliminary clinical study had established the safety of FO extracts at 1,000 mg/day ( 11 ).…”

“…Recently, the effects of lactic acid-fermented oyster extract (FO) containing GABA and lactic acid, produced by lactic acid fermentation of oysters, on bone formation ( 7 ), height growth ( 8 ), and exercise performance improvement ( 9 ) have been reported. Also, a previous study showed that GABA-enriched FO reduced muscle proteolysis by increasing mRNA levels of IGF-1 expression in dexamethasone-treated animals ( 10 ). These data suggest that GABA is a potent bioactive compound for improving muscle health ( 11 ).…”

“…These data suggest that GABA is a potent bioactive compound for improving muscle health ( 11 ). Lactic acid fermentation may further increase GABA content ( 9 , 10 ).…”