An antidiabetic nutraceutical combination of red yeast rice (<i>Monascus purpureus</i>), bitter gourd (<i>Momordica charantia</i>), and chromium alleviates dedifferentiation of pancreatic β cells in db/db mice

Abstract

Antidiabetic properties of red yeast rice, bitter gourd, and chromium have gained scientific support. This study aimed to test whether a nutraceutical combination of these 3 materials prevented dedifferentiation of pancreatic β cells. Male db/db mice (8 weeks of age) were allocated into four groups (DB, DB/L, DB/M, and DB/H; <i>n</i> = 8-10) and fed a high-fat diet containing 0%, 0.2%, 0.4%, or 1% nutraceutical, respectively, whereas wild-type mice receiving a standard diet served as a healthy control (C; <i>n</i> = 10). The nutraceutical contained 10 mg/g monacolin K, 165 µg/g chromium, and 300 mg/g bitter gourd. After 8-weeks dietary treatment, diabetic syndromes (including hyperglycemia, hyperphagia, excessive drinking, polyuria, glucosuria, albuminuria, and glucose intolerance), were improved by the nutraceutical in a dose-dependent fashion. Decreased insulin and increased glucagon in serum and pancreatic islets in db/db mice were abolished in the DB/H group. Furthermore, supplementation curtailed dedifferentiation of β cells, as evidenced by decreasing the dedifferentiation marker (<i>Aldh1a3</i>) and increasing β-cell-enriched genes and transcription factors (<i>Ins1</i>, <i>Ins2</i>, FOXO1, and NKX6.1), as well as nuclear localization of NKX6.1 in pancreatic islets when compared to the DB group. We concluded that this nutraceutical, a combination of <i>Monascus purpureus</i>, <i>Momordica charantia</i>, and chromium, could be used as an adjunct for type 2 diabetes treatment and delay disease progression by sustaining β-cell function.