Kinetics and metabolism of apocynin in the mouse brain assessed with positron-emission tomography

Exploring antithrombotic mechanisms and effective constituents of Lagopsis supina using an integrated strategy based on network pharmacology, molecular docking, metabolomics, and experimental verification in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Thrombosis is a common cause of morbidity and mortality worldwide. Lagopsis supina (Stephan ex Willd.) Ikonn.-Gal. ex Knorring is an ancient Chinese herbal medicine used for treating thrombotic diseases. Nevertheless, the antithrombotic mechanisms and effective constituents of this plant have not been clarified.

AIM OF THE STUDY

This work aimed to elucidate the pharmacodynamics and mechanism of L. supina against thrombosis.

MATERIALS AND METHODS

Systematic network pharmacology was used to explore candidate effective constituents and hub targets of L. supina against thrombosis. Subsequently, the binding affinities of major constituents with core targets were verified by molecular docking analysis. Afterward, the therapeutic effect and mechanism were evaluated in an arteriovenous bypass thrombosis rat model. In addition, the serum metabolomics analysis was conducted using ultra-high performance liquid chromatography coupled with Q-Exactive mass spectrometry.

RESULTS

A total of 124 intersected targets of L. supina against thrombosis were predicted. Among them, 24 hub targets were obtained and their mainly associated with inflammation, angiogenesis, and thrombosis approaches. Furthermore, 9 candidate effective constituents, including (22E,24R)-5α,8α-epidioxyergosta-6,22-dien-3β-ol, aurantiamide, (22E,24R)-5α,8α-epidioxyergosta-6,9 (11),22-trien-3β-ol, lagopsinA, lagopsin C, 15-epi-lagopsin C, lagopsin D, 15-epi-lagopsin D, and lagopsin G in L. supina and 6 potential core targets (TLR-4, TNF-α, HIF-1α, VEGF-A, VEGFR-2, and CLEC1B) were acquired. Then, these 9 constituents demonstrated strong binding affinities with the 6 targets, with their lowest binding energies were all less than -5.0 kcal/mol. The antithrombotic effect and potential mechanisms of L. supina were verified, showing a positively associated with the inhibition of inflammation (TNF-α, IL-1β, IL-6, IL-8, and IL-10) and coagulation cascade (TT, APTT, PT, FIB, AT-III), promotion of angiogenesis (VEGF), suppression of platelet activation (TXB2, 6-keto-PGF1α, and TXB2/6-keto-PGF1α), and prevention of fibrinolysis (t-PA, u-PA, PAI-1, PAI-1/t-PA, PAI-1/u-PA, and PLG). Finally, 14 endogenous differential metabolites from serum samples of rats were intervened by L. supina based on untargeted metabolomics analysis, which were closely related to amino acid metabolism, inflammatory and angiogenic pathways.

CONCLUSION

Our integrated strategy based on network pharmacology, molecular docking, metabolomics, and in vivo experiments revealed for the first time that L. supina exerts a significant antithrombotic effect through the inhibition of inflammation and coagulation cascade, promotion of angiogenesis, and suppression of platelet activation. This paper provides novel insight into the potential of L. supina as a candidate agent to treat thrombosis.

Neuroprotective role of apocynin against pentylenetetrazole kindling epilepsy and associated comorbidities in mice by suppression of ROS/RNS

Epilepsy is a neurological disease that transpires due to the unusual synchronized neuronal discharge within the central nervous system, which drives repetitious unprovoked seizures. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is a complex enzyme accountable for reactive oxygen species (ROS) production, neurodegeneration, neurotoxicity, memory impairment, vitiates normal cellular processes, long term potentiation, and thus, implicated in the pathogenesis of epilepsy. Therefore, the present study was sketched to examine the neuroprotective effect of apocynin, NADPH oxidase inhibitor in pentylenetetrazole kindling epilepsy, and induced comorbidities in mice. Mice (either sex) were given pentylenetetrazole (35 mg/kg, i.p.) every other day up to 29 days, and a challenge test was executed on the 33^rd day. Pretreatment with apocynin (25, 50, and 100 mg/kg, i.p.) was carried out from 1^st to 33^rd day. Rotarod and open field test were performed on the 1^st, 10^th, 20^th, and 30^th days of the study. Animals were tutored on the morris water maze from 30^th to 33^rd day, and the retention was registered on the 34^th day. Tail suspension test and elevated plus maze were sequentially performed on the 32^nd and 33^rd day of the study. On the 34^th day, animals were sacrificed, and their brains were isolated to conduct biochemical estimation. NADPH oxidase activation due to chronic pentylenetetrazole treatment resulted in generalized tonic-clonic seizures, enhanced oxidative stress, remodeled neurotransmitters' level, and resulted in comorbidities (anxiety, depression, and memory impairment). Pretreatment with apocynin significantly restricted the pentylenetetrazole induced seizure severity, ROS production, neurotransmitter alteration, and comorbid conditions by inhibiting the NADPH oxidase enzyme.

Pharmacology of apocynin: a natural acetophenone

Apocynin is a naturally occurring acetophenone, found in the roots of Apocynum cannabinum and Picrorhiza kurroa. Various chemical and pharmaceutical modifications have been carried out to enhance the absorption and duration of action of apocynin, like, formulation of chitosan-based apocynin-loaded solid lipid nanoparticles, chitosan-oligosaccharide based nanoparticles, and biodegradable polyanhydride nanoparticles. Apocynin has been subjected to a wide range of experimental screening and has proved to be useful for amelioration of a variety of disorders, like diabetic complications, neurodegeneration, cardiovascular disorders, lung cancer, hepatocellular cancer, pancreatic cancer, and pheochromocytoma. Apocynin has been primarily reported as an NADPH oxidase (NOX) inhibitor and prevents translocation of its p47^phox subunit to the plasma membrane, observed in neurodegeneration and hypertension. However, recent studies highlight its off-target effects that it is able to function as a scavenger of non-radical oxidant species, which is relevant for its activity against NOX 4 mediated production of hydrogen peroxide. Additionally, apocynin has shown inhibition of eNOS-dependent superoxide production in diabetic cardiomyopathy, reduction of NLRP3 activation and TGFβ/Smad signaling in diabetic nephropathy, diminished VEGF expression and decreased retinal NF-κB activation in diabetic retinopathy, inhibition of P38/MAPK/Caspase3 pathway in pheochromocytoma, inhibition of AKT-GSK3β and ERK1/2 pathways in pancreatic cancer, and decreased FAK/PI3K/Akt signaling in hepatocellular cancer. This review aims to discuss the pharmacokinetics and mechanisms of the pharmacological actions of apocynin.

An Effective NADPH Oxidase 2 Inhibitor Provides Neuroprotection and Improves Functional Outcomes in Animal Model of Traumatic Brain Injury

Traumatic brain injury (TBI) has become a leading cause of death and disability all over the world. Pharmacological suppression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) can inhibit oxidative stress which is implicated in the pathology of TBI. GSK2795039 was reported to target NOX2 to inhibit [Formula: see text] and ROS production. The present study aimed to investigate the effect of GSK2795039 on NOX2 activity and neurological deficits in a TBI mouse model. TBI mouse model was established by a weight-drop to mouse skull. GSK2795039 at a dose of 100 mg/kg was administrated to mice 30 min before TBI. NOX2 expression and activity were detected by Western blot and biochemical method. Neurological damage and apoptosis were detected by behavioral test and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. GSK2795039 significantly inhibited NOX2 expression and activity in the TBI mouse model. It also attenuated TBI-induced neurological deficits, apoptosis, and neurological recovery. The results indicate that GSK2795039 can be used as a potential drug for TBI treatment.