Fertility and early embryonic development toxicity and toxicokinetic study of KFP-H008 in Sprague-Dawley rats.

The novel potassium competitive acid blocker, KFP-H008, developed to overcome the shortcomings of proton pump inhibitors. In this study, KFP-H008 was administered by oral gavage at doses of 0 (control), 15, 45, and 150 mg/kg to Sprague-Dawley rats (24 animals per sex per group). Body weight, food consumption, mortality, sexual cycle, mating behavior, pregnancy, sperm motility, and relative organ weights were evaluated. In a concomitant toxicokinetic (TK) study (10 animals per sex per group), plasma TK parameters and tissue distribution of KFP-H008 were tested. There were obvious effects at the dosage of 150 mg/kg to male rats with decreases of prostate weight and lower weight gain; to female rats with lower weight gain, hair off, and lower corpus luteum count. There were no effects on litter parameters. Time to reach maximum plasma concentrations for KFP-H008 was between 0.5 and 1.0 hr for the 15 and 45 mg/kg groups, while for the 150 mg/kg group it had a delay to 2 hr. Overall, the NOAEL of KFP-H008 was considered to be 45 mg/kg in both genders and the TK study shows that exposure (area under the curve) of male rats was about 1,091.0 ± 530.8 µg/Lhr and to female rats was 1,030.5 ± 512.5 µg/Lhr. Administration of KFP-H008although reaches the reproductive organs, it demonstrated no significant effects on reproductive organs, it did not affect mating, fertility, pregnancy, growth, or morphologic development.

Attenuated Blood-Brain Barrier Dysfunction by XQ-1H Following Ischemic Stroke in Hyperlipidemic Rats.

Following ischemic stroke, blood-brain barrier (BBB) is disrupted and is further aggravated with the corresponding incidence of hyperlipidemia. BBB breakdown promotes inflammation infiltration into the brain, which exacerbates cerebral ischemic injury as a result. Here, we report that 10-O-(N,N-dimethylaminoethyl)-ginkgolide B methanesulfonate (XQ-1H), a novel analog of ginkgolide B, alleviates BBB breakdown in hyperlipidemic rats and protects endothelial cells against inflammatory response. Middle cerebral artery occlusion (MCAO) modeled ischemic stroke in rats. Before surgery, these rats were fed a cholesterol-rich diet to induce an experimental hyperlipidemic condition. Additionally, lipopolysaccharide (LPS) incubation with rat brain microvessel endothelial cells (rBMECs) was applied to mimic hyperlipidemia-induced inflammatory injury of BBB. The results indicated more severe infarct size, increased BBB permeability, excessive secretion of pro-inflammatory cytokines, and exaggerated inflammation infiltration of the brain in hyperlipidemic rats following MCAO when compared to rats fed with normal diet. XQ-1H protected BBB integrity, lessoned brain edema and inflammation penetration, downregulated MMP-9 and VCMA-1 expressions, and extenuated ischemic infarction. XQ-1H alleviated LPS-induced inflammatory response in rBMECs, characterized by promoting cell viability, inhibiting TNF-α, IL-1ß, and IL-6 releasing, and downregulating NF-κB inflammatory signal and downstream proteins, such as VCAM-1 and iNOS. In conclusion, the present study shows that XQ-1H stabilizes BBB function following ischemic stroke in hyperlipidemic rats, and the possible mechanisms may be related to inflammation inhibition.

Therapeutic time window for treatment of focal cerebral ischemia reperfusion injury with XQ-1h in rats.

Pervious experimental studies have shown that XQ-1h has beneficial neuroprotective effect in the cerebral ischemia reperfusion injury. However, the therapeutic time window for treatment of focal cerebral ischemia reperfusion injury with XQ-1h is not clear. Under chloral hydrate anesthesia, transient focal cerebral ischemia was induced in rats by 2h of middle cerebral artery occlusion (MCAO), followed by 24h of reperfusion. Saline as vehicle or XQ-1h at the doses of 31.2, 15.6 and 7.8 mg/kg i.v. was administered at 0.5, 1, 2, 3h after induction of ischemia. Subsequently, 24h after MCAO brain edema, infarct volume, neurological deficits and cerebral blood flow were evaluated. Administrations of XQ-1h at the doses of 31.2mg/kg at 0.5, 1, and 2h after reperfusion of MCAO significantly reduced infarct rate (%) by 75.6% (5.2 ± 1.7), 66.2% (7.2 ± 1.9), and 47.9% (11.1 ± 1.2), respectively. XQ-1h (31.2mg/kg) treatment, 0.5, 1, and 2h after reperfusion produced significant improvement in neurological score compared to vehicle-treated group (P<0.01). Administrations of XQ-1h at the doses of 31.2mg/kg and 15.6 mg/kg at 0.5, 1, and 2h after reperfusion of MCAO significantly increased cerebral blood flow (mv) by 16.9 ± 1.9, 11.7 ± 1.3, 9.5 ± 1.0, respectively (P<0.01). In conclusion the therapeutic time window of XQ-1h for cerebral ischemia reperfusion injury is within 2h. Interestingly, we also discovered that the therapeutic time window of XQ-1h is deeply related with the activity of scavenging oxidative stress products. Further studies need to be conducted more drug combination therapy programs in order to assess the potential clinical application of XQ-1h.

Isolation and structure characterization of related impurities in 10-O-(N,N-dimethylaminoethyl)-ginkgolide B methanesulfonate (XQ-1H) bulk drug and quantitation by a validated RP-LC.

10-O-(N,N-dimethylaminoethyl)-ginkgolide B methanesulfonate (XQ-1H), a novel active derivative of ginkgolide B, is a platelet-activating factor antagonist which is being under clinical trial. Two unknown related impurities were observed in analysis of XQ-1H bulk drug. A scaling up preparative liquid chromatography (Prep LC) was used for isolation of the two impurities. Based on LC-MS/MS and nuclear magnetic resonance (NMR) spectra, they were characterized as 10-O-(N,N-dimethylaminoethyl)-11,12-seco-ginkgolide B (imp-1) and 10-O-(N,N-dimethylaminoethyl)-11,12,2,15-diseco-3,14-dehydroginkgolide B (imp-2), respectively. A reversed-phase liquid chromatography (RP-LC) was developed for simultaneous determination of XQ-1H as well as imp-1 and imp-2. Main variables that significantly influence the chromatographic procedure were optimized and efficient chromatographic separation was achieved on a CN column with mobile phase consisting of 5mM dipotassium hydrogen phosphate (pH 7.5) and methanol delivered in a gradient mode at the flow rate of 1.0mLmin(-1). The method was validated and found to be suitable to check the quality of bulk samples of XQ-1H at test concentration of 5.0mgmL(-1) for a 20microL injection volume.

Blood brain barrier permeability and therapeutic time window of Ginkgolide B in ischemia-reperfusion injury.

The goal of this study was to estimate the blood brain barrier (BBB) permeability of Ginkgolide B in normal condition and models of ischemia both in vivo and in vitro. A sensitive LC-MS/MS analytical method was developed to determinate accurately the concentration of Ginkgolide B in cell, plasma and brain tissue. The injured rat brain microvessel endothelial cells (RBMECs) induced by Na(2)S(2)O(4) served as a hypoxia/reoxygenation model in vitro. Intracellular concentration of Ginkgolide B increased in injured cells in a concentration-dependent manner. As a model of in vivo-ischemia/reperfusion, we performed middle cerebral artery occlusion (MCAO) in rats. Concentration of Ginkgolide B in the brain tissues showed higher in cerebral ischemia-reperfused animals than that in normal rats. To evaluate potential clinical effect of Ginkgolide B, we determined therapeutic time window in MCAO rats. Up to i.v. administration at 2h after reperfusion of rats, Ginkgolide B could decrease infarction volume and brain edema, exerting significant protective effect in cerebral ischemia injury. In conclusion, Ginkgolide B could pass through BBB, especially after ischemia-reperfusion injury of brain, and might be therapeutically effective for ischemia/reperfusion injury of human brain.

Blood-brain barrier breakdown by PAF and protection by XQ-1H due to antagonism of PAF effects.

Hypoxia and reoxygenation set in motion a series of events, including blood-brain barrier breakdown. We examined the content and effect of platelet-activating factor (PAF), which was increased in the rat brain microvessel endothelial cells (RBMECs) during hypoxia and reoxygenation. MTT method was used to assay cell damage; ELISA analysis was used to estimate PAF release after hypoxia and reoxygenation injury; and RT-PCR and Western blotting method were used to assess gene and protein expressions of inducible nitric-oxide synthase (iNOS) in RBMECs under PAF damage. PAF affected intracellular free Ca(2+) levels, increasing [Ca(2+)](i), which caused up-regulation of iNOS. We also examined the blood-brain barrier protective effect of XQ-1H, a novel ginkgolide B derivative. Pretreatment with XQ-1H (10 microM and 3 microM) for 24 h significantly antagonized PAF receptor and inhibited the increase in intracellular calcium concentration and the up-regulation of iNOS in response to PAF under hypoxia and reoxygenation in vitro.