Oral Administration of Glucosamine Improves Vascular Endothelial Function by Modulating Intracellular Redox State

Abstract

SummaryGlucosamine, used to treat osteoarthritis, has been shown to have anti-inflammatory and antiatherosclerotic effects in experimental studies. A recent cohort study has demonstrated that the use of glucosamine was significantly associated with decreased total mortality. Vascular endothelial function is a potent surrogate marker of atherosclerosis and cardiovascular mortality where oxidative stress could participate. Therefore, we investigated whether glucosamine improves vascular endothelial function and intracellular redox state. We examined the effects of oral glucosamine administration (3000 mg/day) for 4 weeks on flow-mediated vasodilation (FMD) and intraerythrocyte glutathione parameters in 20 volunteers. Nineteen age-matched volunteers served as controls. Glucosamine administration significantly increased FMD (from 7.0 ± 2.3 to 8.7 ± 2.3%, P = 0.022). In the control group, FMD did not change. Glucosamine administration significantly increased intraerythrocyte total glutathione levels (from 212.9 ± 46.2 to 240.6 ± 49.4 μmol/L, P = 0.006), intraerythrocyte reduced form of glutathione (GSH) levels (from 124.7 ± 42.6 to 155.2 ± 47.7 μmol/L; P = 0.004) and intraerythrocyte GSH/oxidized form of glutathione (GSSG) ratios (from 3.18 ± 1.64 to 3.88 ± 1.61, P = 0.04). In the control group, any glutathione parameters did not change. Moreover, a stepwise multivariate analysis revealed percent change of GSH/GSSG is the only independent predictor for those of FMD (standardized β = 0.58, P = 0.007) in the glucosamine group. Glucosamine administration improved FMD in association with amelioration of intraerythrocyte GSH/GSSG ratios. These results suggest that oral glucosamine administration might improve vascular endothelial function by modulating intracellular redox state. (Int Heart J 2017; 58: 926-932)

Nutraceuticals have potential for boosting the type 1 interferon response to RNA viruses including influenza and coronavirus

“…30 The dietary dose employed in this study is quite high in the context of previous clinical experience -2.5% of a human diet providing 400 g dry weight daily would correspond to 10 g glucosaminebut an intake of 3 g daily would be practical and is within the range of previous clinical experience. 31 Rather high intakes may be required for significant clinical benefit, inasmuch as this compound is rather inefficiently absorbed after oral administration. 32 Toward a practical nutraceutical strategy for coping with RNA virus infections…”

Calorie Restriction Mimetics: Upstream-Type Compounds for Modulating Glucose Metabolism

“…In a clinical trial, oral administration of GlcN improved vascular endothelial function by modulating the intracellular redox state [90]. According to a large-scale epidemiological study on consumers of various dietary supplements, the use of GlcN was associated with a decrease in total mortality [91].…”

Azithromycin and glucosamine may amplify the type 1 interferon response to RNA viruses in a complementary fashion

“…These considerations suggest that azithromycin and high-dose glucosamine may interact in a complementary fashion to boost the type 1 interferon response to RNA viruses by up-regulating activity of both MDA5 and MAVS. Clinically, glucosamine has been administered at up to 3 grams daily without clear adverse consequences [ 10 ]. A dose of 3 grams, 2 or 3 times daily, conceivably could replicate a measure of the marked protection documented in RNA virus-exposed mice.…”