Tanshinol borneol ester (DBZ) is a novel experimental compound that consists of two chemical structural units from danshensu and borneol. It exhibits efficacious anti-ischemic and anti-atherosclerosis activities in rats. A fecal metabolomics based on Liquid Chromatography-Mass Spectrometry combined with clinical histopathology and blood lipid estimation was employed to assess the efficacy and the metabolic changes caused by administration of DBZ in atherosclerotic rats. There were the typical pathological features of atherosclerosis and significantly increased levels of TC, TG and LDL-C in the atherosclerotic rat group. Nevertheless, atherosclerotic rats administered both DBZ (at a dose of 40 mg kg−1) and simvastatin (at a dose of 20 mg kg−1) showed good therapeutic effects. The results of the metabolomics studies showed that 55 differential metabolites such as sebacic acid, enterodiol, nonanedioic acid, dodecanedioic acid, cholic acid, 13(S)-HPODE, deoxycholic acid, some phosphatidylglycerol and phosphatidic acids were found, indicating that abnormal metabolism occurred in the pathways of fatty acid oxidation, linoleic acid metabolism, bile acid biosynthesis and glycerophospholipid metabolism in atherosclerotic rats. Compared to those in the model group, the contents of 41 differential metabolites showed a tendency to recover to a healthy level after DBZ administration. Metabolomics studies suggested that DBZ exhibited good treatment efficacy against atherosclerosis by adjusting disturbed metabolic pathways related to atherosclerosis. This study could provide an experimental basis for DBZ's application to act as a candidate drug with anti-atherosclerosis activity.
α-Asaronol from Acorus tatarinowii (known as “Shichangpu” in Traditional Chinese medicine) has been proved to possess more efficient antiepileptic activity and lower toxicity than α-asarone (namely “Xixinnaojiaonang” as an antiepileptic drug in China) in our previous study. However, the molecular mechanism of α-asaronol against epilepsy needs to be known if to become a novel antiepileptic medicine. Nuclear magnetic resonance (NMR)-based metabolomics was applied to investigate the metabolic patterns of plasma and the brain tissue extract from pentylenetetrazole (PTZ)-induced seizure rats when treated with α-asaronol or α-asarone. The results showed that α-asaronol can regulate the metabolomic level of epileptic rats to normal to some extent, and four metabolic pathways were associated with the antiepileptic effect of α-asaronol, including alanine, aspartate, and glutamate metabolism; synthesis and degradation of ketone bodies; glutamine and glutamate metabolism; and glycine, serine, and threonine metabolism. It was concluded that α-asaronol plays a vital role in enhancing energy metabolism, regulating the balance of excitatory and inhibitory neurotransmitters, and inhibiting cell membrane damage to prevent the occurrence of epilepsy. These findings are of great significance in developing α-asaronol into a promising antiepileptic drug derived from Traditional Chinese medicine.
Small GTPase or Ras superfamily, including Ras, Rho, Rab, Ran and Arf, are fundamental in regulating a wide range of cellular processes such as growth, differentiation, migration and apoptosis. They share structural and functional similarities for binding guanine nucleotides and hydrolyzing GTP. Dysregulations of Ras proteins are involved in the pathophysiology of multiple human diseases, however there is still a stringent need for effective treatments targeting these proteins. For decades, small GTPases were recognized as 'undruggable' targets due to their complex regulatory mechanisms and lack of deep pockets for ligand binding. NMR has been critical in deciphering the structural and dynamic properties of the switch regions that are underpinning molecular switch functions of small GTPases, which pave the way for developing new effective inhibitors. The recent progress of drug or lead molecule development made for small GTPases profoundly delineated how modern NMR techniques reshape the field of drug discovery. In this review, we will summarize the progress of structural and dynamic studies of small GTPases, the NMR techniques developed for structure-based drug screening and their applications in early-stage drug discovery for small GTPases.