British journal of pharmacology 2017 04 13() doi 10.1111/bph.13816
BACKGROUND AND PURPOSE
Approaches to prevent selective and progressive loss of insulin-producing ß-cells in Type 1 diabetes mellitus (T1DM) will help conquer this prevalent and devastating disease. Curcumin (CUR), a natural anti-inflammatory, suppresses diabetes associated inflammation and cell death. However, very high doses have been tested owing to poor oral bioavailability, making it difficult to translate to the clinic.
We recently prepared biodegradable nanosystems encapsulating curcumin (nCUR), resulting in at least 9-fold improvement in oral bioavailability. In the current study, we tested nCUR’s ability to prevent streptozotocin (STZ)-induced inflammation and apoptosis in pancreatic islet/ß-cells.
Nonfasted rats pretreated with 10 or 50 mg/kg nCUR 6 hours prior to STZ challenge had up to 37% reduction in the glucose levels, while plain CUR (50 mg/kg) results in 12% reduction. This is owing to nCUR’s ability to prevent islet/β-cell death evident from TUNEL assay, and H&E staining. Both CUR and nCUR significantly decreased levels of inflammatory cytokines in pancreatic tissue homogenates that correlated well with minimal histiocytic infiltration. The nCUR, rather than CUR pre-treatment prevented 8-oxo-2′-deoxyguanosine (8-oxo-dG), a sensitive biomarker of reactive oxygen species (ROS)-induced DNA damage in pancreas. Our data in normal rodents indicates that 28 days daily dosing with nCUR (25 to 100 mg/kg) did not cause any deleterious health issues by the carrier.
CONCLUSIONS & IMPLICATIONS
Together, these data indicate a potentially translatable dose of nCUR that is safe and efficacious in improving the ß-cell function, possibly preventing T1DM.