Berberine promotes the recruitment and activation of brown adipose tissue in mice and humans.

Brown adipose tissue (BAT) dissipates metabolic energy and mediates non-shivering thermogenesis, thereby boosting energy expenditure. Increasing BAT mass and activity is expected to be a promising strategy for combating obesity; however, few medications effectively and safely recruit and activate BAT in humans. Berberine (BBR), a natural compound, is commonly used as a nonprescription drug to treat diarrhea. Here, we reported that 1-month BBR intervention increased BAT mass and activity, reduced body weight, and improved insulin sensitivity in mildly overweight patients with non-alcoholic fatty liver disease. Chronic BBR treatment promoted BAT development by stimulating the expression of brown adipogenic genes, enhanced BAT thermogenesis, and global energy expenditure in diet-induced obese mice and chow-fed lean mice, Consistently, BBR facilitated brown adipocyte differentiation in both mouse and human primary brown preadipocytes. We further found that BBR increased the transcription of PRDM16, a master regulator of brown/beige adipogenesis, by inducing the active DNA demethylation of PRDM16 promoter, which might be driven by the activation of AMPK and production of its downstream tricarboxylic acid cycle intermediate α-Ketoglutarate. Moreover, chronic BBR administration had no impact on the BAT thermogenesis in adipose-specific AMPKa1 and AMPKa2 knockout mice. In summary, we found that BBR intervention promoted recruitment and activation of BAT and AMPK-PRDM16 axis was indispensable for the pro-BAT and pro-energy expenditure properties of BBR. Our findings suggest that BBR may be a promising drug for obesity and related metabolic disorders in humans partially through activating BAT.

Design, synthesis and biological evaluation of 4,7,12,12a-tetrahydro-5H-thieno[3',2':3,4]pyrido[1,2-b]isoquinolines as novel adenosine 5'-monophosphate-activated protein kinase (AMPK) indirect activators for the treatment of type 2 diabetes.

A series of novel berberine derivatives, 4,7,12,12a-tetrahydro-5H-thieno[3',2':3,4]pyrido[1,2-b]isoquinolines was designed, synthesized, and biologically evaluated for their anti-diabetic activity. Following the evaluation in two types of cells, compounds 4aa, 4bq, and 4bv stimulated glucose consumption (1.8- to 2.3-fold), reduced gluconeogenesis (60-85%), inhibited mitochondria respiratory chain complex I and activated AMPK indirectly. In a db/db mice model, compounds 4bq and 4bv lowered fasting blood glucose at a dose of 120 mg/kg/day. In addition, compounds 4bq and 4bv were found to possess improved pharmacokinetic profiles (bioavailability 45 and 106%, respectively) compared to berberine. Compounds 4bq and 4bv exhibited no obvious hERG inhibition (IC50 > 10 µM).

Malonylginsenosides with Potential Antidiabetic Activities from the Flower Buds of Panax ginseng.

LC-MS-guided phytochemical isolation of malonylginsenosides, featuring neutral elimination of CO2 and C3H2O3 by the negative mode collision-induced dissociation, from the flower buds of Panax ginseng led to the isolation of 19 malonyl-substituted triterpenoid saponins. They include 15 new malonylginsenosides, malonylfloralginsenosides-Re1-Re3 (1-3), -Rb1 and -Rb2 (4, 5), -Rd1-Rd6 (6-11), and -Rc1-Rc4 (12-15), and the known m-Rb1, m-Rc, m-Rb2, and m-Rd (16-19). Compound 11 represents the first dimalonyl saponin isolated from the Panax genus, while 2-4, 9, and 10 are five ginsenosides with single malonylation at the C-20 sugar chain. The antidiabetic activities of nine of these malonyl-substituted ginsenosides (1, 3, 4, 8, 13, and 16-19) and five of the corresponding non-malonyl ginsenosides (Re, Rb1, Rb2, Rc, and Rd) were evaluated by L6 myotubes' glucose consumption and AMPKα2ß1γ1 activation. Ginsenoside Rb2, 1, and 18 promoted glucose consumption of differentiated L6 myotubes, while ginsenosides Rb1, Rb2, and Rd and the malonylginsenosides 4, 8, 13, 16, 17, and 19 activated AMPKα2ß1γ1 (EC50: 0.0168-2.8 µM, fold: 1.7-4.7).

Recyclable Hypervalent-Iodine-Mediated Dehydrogenative Cyclopropanation under Metal-Free Conditions.

A method is developed for the synthesis of cyclopropanes from the C(sp2)-C(sp3) single bonds of ß-keto esters with activated methylene compounds under metal-free conditions in the presence of 5-trimethylammonio-1,3-dioxo-1,3-dihydro-1λ5-benzo[d][1,2]iodoxol-1-ol anion (AIBX), a recyclable water-soluble hypervalent iodine(V) reagent developed by our group. This mild, efficient method has a wide substrate scope and good functional group tolerance and is complementary to existing cyclopropanation strategies. The method can be used to construct polysubstituted ring-fused cyclopropanes and is amenable to further synthetic transformations for construction of complex biologically active molecules as well as asymmetric cyclopropanes (90% de) when a chiral ester auxiliary is used.