Propentofylline reverses delayed remyelination in streptozotocin-induced diabetic rats

Propentofylline Improves Thiol-Based Antioxidant Defenses and Limits Lipid Peroxidation following Gliotoxic Injury in the Rat Brainstem

Propentofylline (PROP) is a methylated xanthine compound that diminishes the activation of microglial cells and astrocytes, which are neuronal cells strongly associated with many neurodegenerative diseases. Based on previously observed remyelination and neuroprotective effects, PROP has also been proposed to increment antioxidant defenses and to prevent oxidative damage in neural tissues. Since most neurodegenerative processes have free radicals as molecular pathological agents, the aim of this study was to evaluate the antioxidant effects of 12.5 mg·kg^-1·day^-1 PROP in plasma and the brainstem of Wistar rats exposed to the gliotoxic agent 0.1% ethidium bromide (EB) for 7-31 days. The bulk of the data here demonstrates that, after 7 days of EB treatment, TBARS levels were 2-fold higher in the rat CNS than in control, reaching a maximum of 2.4-fold within 15 days. After 31 days of EB treatment, lipoperoxidation in CNS was still 65% higher than that in the control. Clearly, PROP treatment limited the progression of lipoperoxidation in EB-oxidized CNS: it was, for example, 76% lower than in the EB-treated group after 15 days. Most of these effects were associated with PROP-induced activity of glutathione reductase in the brainstem: the EB + PROP group showed 59% higher GR activity than that of the EB or control groups within 7 days. In summary, aligning with previous studies from our group and with literature about MTXs, we observed that propentofylline (PROP) improved the thiol-based antioxidant defenses in the rat brainstem by the induction of the enzymatic activity of glutathione reductase (GR), which diminished lipid oxidation progression and rebalanced the redox status in the CNS.

Synthesis and evaluation of novel xanthine-acrylamides and xanthine-acrylates as insecticidal agents

BACKGROUND

The design and discovery of novel pesticidal agents according to bioactive natural products is an important aspect of agrochemical innovation. New xanthine derivatives derived from natural xanthine or methylxanthines are rich resources that possess great potential to afford new active pesticidal molecules. Herein novel xanthine derivatives were designed through a strategy of combining the methylxanthine caffeine skeleton with the acrylamide or acrylate motif of cinnamic acid derivatives.

RESULTS

A series of novel (E)-3-(1,3,7-trimethyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-8-yl)acrylic acid derivatives, caffeine-(E)-acrylamides and caffeine-(E)-acrylates, were synthesized and confirmed via melting points, ¹ H NMR, ¹³ C NMR and high-resolution mass spectrometry. A single crystal of compound I12 was obtained to illustrate the trans-configuration of the vinyl double bond. Preliminary insecticidal evaluations showed that some of the compounds had favorable insecticidal potentials against Mythimna separata Walker at 200 mg L^-1 . Some of the compounds exhibited excellent insecticidal activity against Plutella xylostella L. at low test concentrations, e.g. I18 and I24 with LC₅₀ values of 0.0435 and 0.0133 mg L^-1 , respectively, were found to be more potent than the insecticide control triflumuron. The structure-activity relationship (SAR) analysis is also given in detail.

CONCLUSION

Compounds I12, I18, I24 and I26 generated from the integration of natural methylxanthine (caffeine) and acrylate moieties could be novel insecticidal leading compounds for further structural optimization. The SAR analysis may bring a new inspiration to the extensive and deep investigations on new xanthine derivatives in the agrochemical area.

Xanthine scaffold: scope and potential in drug development

Medicinal plants have been the basis for discovery of various important marketed drugs. Xanthine is one such lead molecule. Xanthines in various forms (caffeine, theophylline, theobromine, etc) are abode in tea, coffee, cocoa, chocolate etc. giving them popular recognition. These compounds are best known for their diverse pharmaceutical applications as cyclic nucleotide phosphodiesterase inhibition, antagonization of adenosine receptor, anti-inflammatory, anti-microbial, anti-oxidant and anti-tumor activities. These properties incentivize to use xanthine as scaffold to develop new derivatives. Chemical synthesis contributes greater diversity in xanthine based derivatisation. With highlighting the existing challenges in chemical synthesis, the present review focuses the probable solution to fill existing lacuna. The review summarizes the available knowledge of xanthine based drugs development along with exploring new xanthine led chemical synthesis path for bringing diversification in xanthine based research. The main objective of this review is to explore the immense potential of xanthine as scaffold in drug development.

Effect of chronic intraperitoneal aminoguanidine on memory and expression of Bcl-2 family genes in diabetic rats

Long-term hyperglycemia associates with memory defects via hippocampal cells damaging. The aim of the present study was to examine the effect of 1 month of i.p. injections of AG on passive avoidance learning (PAL) and hippocampal apoptosis in rat. Eighty male rats were divided into 10 groups: control, nondiabetics and STZ-induced diabetics treated with AG (50, 100, 200, and 400 mg/kg, i.p.). PAL and the Bcl-2 family gene expressions were determined. Diabetes resulted in memory and Bcl-2 family gene expression deficits. AG (50 and 100 mg/kg) significantly improved the learning and Bcl-2, Bcl-xl, Bax, and Bak impairment in diabetic rats. However, negative effects were indicated by higher doses of the drug (200 and 400 mg/kg). Present study suggests that 1 month of i.p. injections of lower doses of AG, may improve the impaired cognitive tasks in STZ-induced diabetic rats possibly by modulating Bcl-2 family gene expressions.