A Novel Glucomannan from Dendrobium officinale Inhibits Obesity and Improves Insulin Sensitivity through Regulating Adipogenesis and Lipid Metabolism.

Abstract

Dendrobium officinale polysaccharides (DOPs), the main active components of D. officinale, exhibit diverse pharmacological activities. Although crude DOPs exhibit antiobesity potential, research investigating purified DOPs remains limited. This study purified a bioactive polysaccharide (DOP-1) from D. officinale and revealed that DOP-1 is a homogeneous glucomannan with a molecular weight (Mw) of 1.09 × 105 Da. The primary backbone of DOP-1 is composed of →4)-α-d-Glcp-(1→, →4,6)-α-d-Glcp-(1→, →4)-β-d-Manp-(1→, and →4)-β-d-2-OAc-Manp-(1→ units, while the side chain features α-d-Glcp-(1→ residues. Animal studies revealed that DOP-1 prevents high-fat diet (HFD)-induced obesity by mitigating weight gain, reducing inflammation, improving glucose and lipid metabolism, and alleviating insulin resistance (IR). Additionally, DOP-1 inhibited 3T3-L1 preadipocyte differentiation and lipid accumulation. Concurrently, DOP-1 enhanced lipolysis, fatty acid oxidation, and browning, ultimately enhancing insulin sensitivity in mature adipocytes. Furthermore, DOP-1 showed similar effects in HFD-fed mice. These findings suggest that DOP-1 holds potential as a functional food for obesity prevention and treatment.