Development and validation of LC-MS/MS method for determining the metabolic stability, pharmacokinetics, and dose proportionality of a novel anti-inflammatory cofilin inhibitor.

A novel small molecule cofilin inhibitor (SZ-3) has recently become the focus of investigation for targeting neuroinflammation in different neurodegenerative diseases. In the present study, the metabolic stability, blood-brain barrier (BBB) penetration, and tissue concentration of SZ-3 were evaluated to support our future studies. In silico drug metabolism prediction was investigated using the StarDrop WhichP450 module. LC-MS/MS method was developed and validated to quantify the SZ-3 for in-vitro and in-vivo studies. The in-vitro metabolic stability was performed using human liver microsomes (HLMs), and the in-vivo pharmacokinetics were investigated in mice after a single intraperitoneal (IP) injection or oral (P.O.) administration, followed by a collection of blood and brain samples at different time points. The dose-proportionality was also evaluated after a single IP injection of three ascending doses (5, 10, and 25 mg/kg). In-vitro results showed that SZ-3 has a moderate intrinsic clearance (Clint) value of 17.42 ml/min/mg with a half-life (t1/2) value of 39.77 mins, indicative of good bioavailability. In vivo study revealed that SZ-3 was rapidly absorbed, entered the brain, and yielded a good concentration of the unbound drug after IP and oral administration. However, the higher maximum concentration (Cmax) values of IP and P.O. (2244 ng/ml and 1069 ng/g, respectively) revealed that the IP administration led to higher blood and brain concentrations than the P.O. Furthermore, Cmax and area under the curve (AUC) of SZ-3 increased in a dose-proportional manner between the three ascending doses. These results will guide us in optimizing the dosing regimen for future SZ-3 pharmacological studies targeting neuroinflammation.

The influence of gut microbiota alteration on age-related neuroinflammation and cognitive decline.

Recent emerging research on intestinal microbiota and its contribution to the central nervous system during health and disease has attracted significant attention. Age-related intestinal microbiota changes initiate brain aging and age-related neurodegenerative disorders. Aging is one of the critical predisposing risk factors for the development of neurodegenerative diseases. Maintaining a healthy gut microbiota is essential for a healthy body and aging, but dysbiosis could initiate many chronic diseases. Understanding the underlying mechanisms of gut microbiota alterations/dysbiosis will help identify biomarkers for aging-related chronic conditions. This review summarizes recent advances in microbiota-neurodegenerative disease research and will enhance our understanding of gut microbiota dysbiosis and its effects on brain aging.

The role of cofilin in age-related neuroinflammation.

Aging brain becomes susceptible to neurodegenerative diseases due to the shifting of microglia and astrocyte phenotypes to an active "pro-inflammatory" state, causing chronic low-grade neuroinflammation. Despite the fact that the role of neuroinflammation during aging has been extensively studied in recent years, the underlying causes remain unclear. The identification of relevant proteins and understanding their potential roles in neuroinflammation can help explain their potential of becoming biomarkers in the aging brain and as drug targets for prevention and treatment. This will eventually reduce the chances of developing neurodegenerative diseases and promote healthier lives in the elderly. In this review, we have summarized the morphological and cellular changes in the aging brain, the effects of age-related neuroinflammation, and the potential role of cofilin-1 during neuroinflammation. We also discuss other factors contributing to brain aging and neuroinflammation.

Analytical studies on the 2-naphthoyl substituted-1-n-pentylindoles: Regioisomeric synthetic cannabinoids.

The six 1-n-pentyl-2-, 3-, 4-, 5-, 6- and 7-(2-naphthoyl)-indoles each have the same substituents attached to the indole ring, identical elemental composition (C24H23NO) yielding identical nominal and accurate masses. The electron ionization mass spectra of the 2-naphthoyl substituted isomers share equivalent major fragment ions resulting from cleavage of the groups attached to the central indole nucleus with some differences in relative abundances. These six regioisomers were successfully resolved on an Rtx-5 and Rxi-17Sil MS stationary phases and the molecules having both substituent groups on the same side of the indole ring (1,2- and 1,7-substituents) show the least retention. The more linear molecules have higher relative retention properties. A comparison of the GC properties of the 1-naphthoyl- and 2-naphthoyl groups attached at identical positions of the indole ring showed higher GC retention for the 2-naphthoyl substituted isomer in all cases evaluated. The amide inverse isomers (1-naphthoyl-3-n-pentylindoles) were separated from the 1-n-pentyl-3-naphthoyl-indoles on an Rtx-200 stationary phase. The two inverse amide isomers having the 1- and 2-naphthoyl groups substituted at the 1-position of the indole ring elute before either of the N-alkyl-indole isomers having the 1- and 2-naphthoyl groups substituted at the 3-position of the indole ring. The amide inverse isomers yield EI mass spectra easily distinguishing these amides from the ketone isomers having the naphthoyl groups at the indole 3-position.

GC-MS differentiation of the six regioisomeric dimethoxybenzoyl-1-pentylindoles: Isomeric cannabinoid substances.

The six regioisomeric 1-pentyl-3-dimethoxybenzoylindoles can be differentiated by a combination of EI-MS and FT-IR spectra. The six regioisomeric 1-n-pentyl-3-(dimethoxybenzoyl)-indoles represent potential designer modifications in the synthetic cannabinoid drug category. The analytical properties and methods of regioisomeric differentiation were developed in this study. The base peaks in these six spectra allow these compounds to be subdivided into three groups of two compounds each, the m/z 334 ion is the base peak for the 2,4- and 2,6-dimethoxybenzoyl isomers (compounds 2 and 4), the 2,3- and 2,5-dimethoxybenzoylindole isomers (compounds 1 and 3) show the m/z 200 ion of base peak intensity and the 3,4- and 3,5-isomers (compounds 5 and 6) show the molecular ion as the base peak, m/z 351. The four isomers having a methoxy group substituted at the ortho position show a unique fragment ion occurring at [M-17](+). An interesting fragment ion at m/z 200 is significant in the 2,3 and 2,5 isomers and completely absent in the 3,4 and 3,5 isomers. Minor peaks for m/z 200 appear in the mass spectra of the 2,4 and 2,6-isomers. This set of regioisomeric compounds was well resolved by capillary gas chromatography on a dimethylpolysiloxane stationary phase. The elution order appears related to the degree of substituent crowding in the dimethoxybenzoyl group. FTIR spectra provide useful data for differentiation among these regioisomeric compounds. Infrared absorption spectral data provide distinguishing and characteristic information to individualize the regioisomers in this set of compounds.