1,2,3,4,6-Penta-O-galloyl-d-glucose Interrupts the Early Adipocyte Lifecycle and Attenuates Adiposity and Hepatic Steatosis in Mice with Diet-Induced Obesity.

Phytochemicals that interrupt adipocyte lifecycle can provide anti-obesity effects. 1,2,3,4,6-penta-O-galloyl-d-glucose (PGG) is a tannin with two isomers that occurs widely in plants and exhibits various pharmacological activities. The aim of the investigation is to comprehensively examine effects of PGG isomer(s) on adipocyte lifecycle and diet-induced obesity. Human mesenchymal stem cells (hMSC), 3T3-L1 fibroblasts, and H4IIE hepatoma cells were used to determine the effects of PGG isomers on cell viability and adipogenesis. Mice with diet-induced obesity were generated from male C57/BL6 mice fed with a 45% high fat diet. Oral administration of ß-PGG (0.1 and 5 mg/kg) lasted for 14 weeks. Viability was reduced by repeated PGG treatment in hMSC, preadipocytes, and cells under differentiation. PGG mainly induces apoptosis, and this effect is independent of its insulin mimetic action. In vivo, administration of ß-PGG attenuated shortening of the colon, hyperlipidaemia, fat cells and islet hypertrophy in DIO mice. Hepatic steatosis and related gene expression were improved along with glucose intolerance. Increased serum adiponectin, leptin, and glucagon-like peptide-1 levels were also observed. In conclusion, repeated PGG treatment interrupts the adipocyte lifecycle. PGG administration reduces adiposity and fatty liver development in DIO mice, and therefore, PGG could aid in clinical management of obesity.

Hydroxysafflor Yellow A Confers Neuroprotection from Focal Cerebral Ischemia by Modulating the Crosstalk Between JAK2/STAT3 and SOCS3 Signaling Pathways.

Natural bioactive compounds have increasingly proved to be promising in evidence- or target-directed treatment or modification of a spectrum of diseases including cerebral ischemic stroke. Hydroxysafflor yellow A (HSYA), a major active component of the safflower plant, has drawn more interests in recent year for its multiple pharmacological actions in the treatment of cerebrovascular and cardiovascular diseases. Although the Janus kinase signaling, such as JAK2/STAT3 pathway, has been implicated in the modulation of the disease, the inhibition or activation of the pathway that contributed to the neuronal prevention from ischemic damages remains controversial. In this study, a series of experiments were performed to examine the dose- and therapeutic time window-related pharmacological efficacies of HSYA with emphasis on the HSYA-modulated interaction of JAK2/STAT3 and SOCS3 signaling in the MCAO rats. We found that HSYA treatment significantly rescued the neurological and functional deficits in a dose-dependent manner in the MCAO rats within 3 h after ischemia. HSYA treatment with a dosage of 8 mg/kg or higher markedly downregulated the expression of the JAK2-mediated signaling that was activated in response to ischemic insult, while it also promoted the expression of SOCS3 coordinately. In the subsequent experiments with the use of the JAK2 inhibitor WP1066, we found that the treatment of WP1066 alone or combination of WP1066/HSYA all exhibited inhibitory effects on JAK2-mediated signaling, while there was no influence on the SOCS3 activity of corresponding efficacious data in the MCAO rats, suggesting that excessive activation of JAK2/STAT3 might be necessary for HSYA to provoke SOCS3-negative feedback signaling. Taking together, our study demonstrates that HSYA might modulate the crosstalk between JAK2/STAT3 and SOCS3 signaling pathways that eventually contributed to its therapeutic roles against cerebral ischemic stroke.

Hydroxysafflor Yellow A (HSYA) Improves Learning and Memory in Cerebral Ischemia Reperfusion-Injured Rats via Recovering Synaptic Plasticity in the Hippocampus.

Hydroxysafflor yellow A (HSYA) is the major active chemical component of the safflower plant flower, which is widely used in Chinese medicine for cerebrovascular and cardiovascular disease treatment. Recent studies have demonstrated that HSYA exerts neuroprotective effect on cerebral ischemia, such as neuronal anti-apoptosis, antioxidant activity and oxygen free radical-scavenging. However, whether and how HSYA has a protective effect on cognitive impairment induced by cerebral ischemia reperfusion remains elusive. In the present study, by using the middle cerebral artery occlusion (MCAO) model, we found that 8 mg/kg and 16 mg/kg HSYA administration by common carotid artery (CCA) injection improved impaired cognitive function in Morris water maze (MWM) and passive avoidance tasks, but not 4 mg/kg HSYA treatment, suggesting that HSYA treatment in a certain concentration can improve cognitive impairment in MCAO rats. Furthermore, we found that 8 mg/kg HSYA treatment rescued the impaired long-term potentiation (LTP) in hippocampus of MCAO rats. Taken together, these results for the first time demonstrate that HSYA has the capacity to protect cognitive function and synaptic plasticity against cerebral ischemia-reperfusion injury, and provide a new insight that HSYA may be a promising alternative for recovery of cognitive dysfunction after brain ischemic injury.

Modeling of hydrogen bonds in monohydrated 2,4-dithiothymine: an ab initio and AIM study.

Twelve tautomers of 2,4-dithiothymine are calculated at the MP2/6-31+G(d) level, and the most stable one is referred to the di-keto form (P12). Then four H-bonded complexes between P12 and water are optimized at the MP2/6-31+G(d) level of theory. The calculation of vibrational frequencies and natural bond orbital analysis are also carried out at the same level to investigate the hydrogen bonds involved in all the systems. Within all the four complexes, three types of hydrogen bonds are formed, in which the O-H...S and N-H...O bonds are the normal bonds with the X-H bond elongation and red shift of the corresponding stretch frequencies, while the C-H...O interaction is an improper, blue-shifting hydrogen bond accompanied with the contraction of the C-H bond and a blue shift of the C-H stretch frequency. The topological properties are investigated with the atoms-in-molecules (AIM) theory. The NMR chemical shielding for the isolated and the four monohydrated 2,4-dithiothymine are calculated using the "gauge-including atomic orbital" (GIAO) method. The 1H chemical shifts are influenced by the formation of hydrogen bonds.