In Vitro and In Vivo Effects of Fermented Oyster-Derived Lactate on Exercise Endurance Indicators in Mice

Abstract

Exogenous lactate administration has more recently been investigated for its various prophylactic effects. Lactate derived from potential functional foods, such as fermented oyster extract (FO), may emerge as a practical and effective method of consuming exogenous lactate. The current study endeavored to ascertain whether the lactate derived from FO may act on muscle cell biology, and to what extent this may translate into physical fitness improvements. We examined the effects of FO in vitro and in vivo, on mouse C2C12 cells and exercise performance indicators in mice, respectively. In vitro, biochemical analysis was carried out to determine the effects of FO on lactate content and muscle cell energy metabolism, including adenosine triphosphate (ATP) activity. Western blot analysis was also utilized to measure the protein expression of total adenosine monophosphate-activated protein kinase (AMPK), p-AMPK (Thr172), lactate dehydrogenase (LDH), succinate dehydrogenase (SDHA) and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) in response to FO administration. Three experimental groups were formed: a positive control (PC) treated with 1% horse serum, FO10 treated with 10 μg/mL and FO50 treated with 50 μg/mL. In vivo, the effects of FO supplementation on exercise endurance were measured using the Rota-rod test, and Western blot analysis measured myosin heavy-chain 2 (MYH2) to assess skeletal muscle growth, alongside p-AMPK, total-AMPK, PGC-1α, cytochrome C and UCP3 protein expression. Biochemical analysis was also performed on muscle tissue to measure the changes in concentration of liver lactate, lactate dehydrogenase (LDH), glycogen and citrate. Five groups (n = 10/per group) consisted of a control group (CON), exercise group (Ex), positive control treated with Ex and 500 mg/kg Taurine (Ex-Tau), Ex and 100 mg/kg FO supplementation (Ex-FO100) and Ex and 200 mg/kg FO supplementation (Ex-FO200) orally administered over the 4-week experimental period.FO50 significantly increased PGC-1α expression (p < 0.001), whereas both FO10 and FO50 increased the expression of p-AMPK (p < 0.001), in C2C12 muscle cells, showing increased signaling important for mitochondrial metabolism and biogenesis. Muscle lactate levels were also significantly increased following FO10 (p < 0.05) and FO50 (p < 0.001). In vivo, muscle protein expression of p-AMPK (p < 0.05) and PGC-1α were increased, corroborating our in vitro results. Cytochrome C also significantly increased following FO200 intake. These results suggest that the effects of FO supplementation may manifest in a dose-response manner. FO administration, in vitro, and supplementation, in vivo, both demonstrate a potential for improvements in mitochondrial metabolism and biogenesis, and even for potentiating the adaptive effects of endurance exercise. Mechanistically, lactate may be an important molecule in explaining the aforementioned positive effects of FO.

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

“…Lactate is known to have antioxidant effects by modulating Nfr2 and reduced cell death which is induced by ROS [ 44 ]. Through the specialized fermentation process, the oyster extract has enriched GABA and lactate, increasing the oyster’s bioactive properties [ 45 ].…”

“…FO extract was obtained from Marine Bioprocess Co., Ltd. (Gijang, Busan, Korea). For extraction, FO was prepared by fermentation with Lactobacillus brevis BJ20 [ 29 , 45 , 62 , 63 , 64 ], and glutamic acid and dextrin were used on behalf of monosodium glutamate and an excipient, respectively. Glutamate was used as a precursor to producing GABA through a decarboxylation reaction for fermentation with Lactobacillus brevis BJ20 [ 45 , 62 , 63 , 64 ].…”

“…For extraction, FO was prepared by fermentation with Lactobacillus brevis BJ20 [ 29 , 45 , 62 , 63 , 64 ], and glutamic acid and dextrin were used on behalf of monosodium glutamate and an excipient, respectively. Glutamate was used as a precursor to producing GABA through a decarboxylation reaction for fermentation with Lactobacillus brevis BJ20 [ 45 , 62 , 63 , 64 ]. In this study, used FO was the same batch as used that in a previous report [ 45 , 62 , 63 , 64 ], which was composed of 46 g/100 g carbohydrate, 36 g/100 g crude protein, 6.3 g/100 g sugars, 114 mg/g GABA, and 40.3 mg/g lactic acid [ 45 , 64 ].…”

“…Glutamate was used as a precursor to producing GABA through a decarboxylation reaction for fermentation with Lactobacillus brevis BJ20 [ 45 , 62 , 63 , 64 ]. In this study, used FO was the same batch as used that in a previous report [ 45 , 62 , 63 , 64 ], which was composed of 46 g/100 g carbohydrate, 36 g/100 g crude protein, 6.3 g/100 g sugars, 114 mg/g GABA, and 40.3 mg/g lactic acid [ 45 , 64 ]. FO was diluted with saline to adjust the final treatment concentration before use.…”

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

“…They also contain a large amount of phosphorus taurine (based on a 4.2%/dry base) and represent one of the world’s top 10 seafood foods rich in essential minerals such as glycogen, vitamins, iron, and iodine ( 6 ). 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 ).…”