Anti-glycation and anti-oxidative effects of a phenolic-enriched maple syrup extract and its protective effects on normal human colon cells

Abstract

Oxidative stress and free radical generation accelerate the formation of advanced glycation endproducts (AGEs) which are linked to several chronic diseases. Published data suggest that phenolic-rich plant foods, show promise as natural anti-AGEs agents due to their anti-oxidation capacities. A phenolic-enriched maple syrup extract (MSX) has previously been reported to show anti-inflammatory and neuroprotective effects but its anti-AGE effects remain unknown. Therefore, herein, we investigated the anti-glycation and anti-oxidation effects of MSX using biochemical and biophysical methods. MSX (500 μg/mL) reduced the formation of AGEs by 40% in the bovine serum albumin (BSA)-fructose assay and by 30% in the BSA-methylglyoxal (MGO) assay. MSX also inhibited the formation of crosslinks typically seen in the late stage of glycation. Circular dichroism and differential scanning calorimeter analyses demonstrated that MSX maintained the structure of BSA during glycation. In the anti-oxidant assays, MSX (61.7 μg/mL) scavenged 50% of free radicals (DPPH assay) and reduced free radical generation by 20% during the glycation process (electron paramagnetic resonance time scan). In addition, the intracellular levels of hydrogen peroxide induced reactive oxygen species were reduced by 27-58% with MSX (50-200 μg/mL) in normal/non-tumorigenic human colon CCD-18Co cells. Moreover, in AGEs and MGO challenged CCD-18Co cells, higher cellular viabilities and rapid extracellular signal–regulated kinase (ERK) phosphorylation were observed in MSX treated cells, indicating its protective effects against AGEs-induced cytotoxicity. Overall, this study supports the biological effects of MSX, and warrants further investigation of its potential as a dietary agent against diseases mediated by oxidative stress and inflammation.

Phenolic‐enriched maple syrup extract protects human keratinocytes against hydrogen peroxide and methylglyoxal induced cytotoxicity

“…MSX (12.5, 25, and 50 μg/mL) reduced H 2 O 2 ‐ and MGO‐induced ROS production by 44.4%, 59.0%, and 69.4%, and 34.9%, 51.3%, and 56.6%, respectively, as compared to the model group (Figure 2). This is in agreement with our previously reported studies showing that MSX exerts cytoprotective effects by attenuating cellular ROS in normal human colon CCD‐18Co cells 13 and murine microglial BV‐2 cells ( 15,16 ).…”

“…Among these natural products, we reported that phenolic‐enriched extracts of pomegranate fruit ( Punica granatum ) and red maple leaves ( Acer rubrum ) showed potent inhibitory effects against AGEs formation and protected human keratinocytes against oxidative stress induced cytotoxicity ( 12,15,16,21 ). In addition, we also reported that a polyphenol‐enriched maple syrup extract (MSX) showed inhibitory activity against AGEs formation and protective effects against AGEs‐ and MGO‐induced cytotoxicity in normal human colon cells 13 . MSX has also been reported to show a diverse range of biological activities including antioxidant, antidiabetic, anti‐inflammatory, and anti‐neuroinflammatory effects ( 13,15,16,22,23 ) but its skin protective effects in human keratinocytes remain unknown.…”

Glucose‐mediated protein glycation: Contribution of methanolic extract of Ceratonia siliqua L. in protection and in vitro potential inhibition of acetylcholinesterase

“…A number of plant derived compounds showed hypoglycemic properties (Sefi, Fetoui, Makni, & Zeghal, ) such total phenols, flavonoids, terpenoids, and coumarins; reducing glucose levels and increasing the insulin amounts in plasma (Santosh Tupe et al, ). In point of fact, several studies have noted the capacity of phenolic compounds (PC) to inhibit AGEs (Ah Jung et al, ); mainly flavonoids (Liu et al, ). It is also interesting to point out that PC present the ability to scavenge reactive carbonyls through the formation of adducts with them (Wang, Yagiz, Buran, Do Nascimento Nunes, & Gu, ) and show a reducing activity of free radicals contributing to the inhibition of glycation (Adisakwattana et al, ; Ramkissoon, Mahomoodally, Ahmed, & Subratty, ).…”

Anti-Diabetic Effects of Phenolic Extract from Rambutan Peels (Nephelium lappaceum) in High-Fat Diet and Streptozotocin-Induced Diabetic Mice

“…However, these drugs demonstrate significant side effects, including weight gain and gastrointestinal distress. Therefore, finding new potential natural products that prevent DM is necessary [4]. Phenolic compounds are important secondary plant metabolites that determine the sensory and nutritional qualities of fruits, vegetables, and other plant products.…”