Anticonvulsant effects of isopimpinellin and its interactions with classic antiseizure medications and borneol in the mouse tonic-clonic seizure model: an isobolographic transformation

BACKGROUND

Overwhelming evidence indicates that some naturally occurring coumarins and terpenes are widely used in folk medicine due to their various therapeutic effects affecting the brain. Antiseizure medications (ASMs) are the principal treatment option for epilepsy patients, although some novel strategies based on naturally occurring substances are intensively investigated. This study was aimed at determining the influence of isopimpinellin (ISOP-a coumarin) when administered either separately or in combination with borneol (BOR-a monoterpenoid), on the antiseizure potencies of four classic ASMs (carbamazepine (CBZ), phenytoin (PHT), phenobarbital (PB), and valproate (VPA)) in the mouse model of maximal electroshock-induced (MES) tonic-clonic seizures.

MATERIALS

Tonic-clonic seizures were evoked experimentally in mice after systemic (ip) administration of the respective doses of ISOP, BOR, and classic ASMs. Interactions for two-drug (ISOP + a classic ASM) and three-drug (ISOP + BOR + a classic ASM) mixtures were assessed isobolographically in the mouse MES model.

RESULTS

ISOP (administered alone) had no impact on the anticonvulsant potencies of four classic ASMs. Due to the isobolographic transformation of data, the combination of ISOP + VPA exerted an antagonistic interaction, whereas the two-drug mixtures of ISOP + CBZ, ISOP + PHT, and ISOP + PB produced additive interactions in the mouse MES model. The three-drug combinations of ISOP + BOR with CBZ and PHT produced additive interactions, while the three-drug combinations of ISOP + BOR with PB and VPA exerted synergistic interactions in the mouse MES model.

CONCLUSIONS

The most intriguing interaction was that for ISOP + VPA, for which the addition of BOR evoked a transition from antagonism to synergy in the mouse MES model.

Isopimpinellin extends antiangiogenic effect through overexpression of miR-15b-5p and downregulating angiogenic stimulators

BACKGROUND

Angiogenesis is the formation of new blood vessels from an existing vasculature through a series of processes such as activation, proliferation, and directed migration of endothelial cells. Angiogenesis is instrumental in the metastatic spread of tumors. Isopimpinellin, a furanocoumarin group of phytochemicals, is an anticarcinogenic agent. However, no studies have proven its antiangiogenic effects. The current study thus aimed to screen the antiangiogenic effect of isopimpinellin.

METHODS AND RESULTS

Human Umblical Vein Endothelial Cell (HUVEC) as an in vitro model and zebrafish embryos as an in vivo model was used in this study. The experimental results showed that isopimpinellin effectively inhibited HUVEC proliferation, invasion, migration, and tube formation, which are the key steps in angiogenesis by markedly suppressing the expression of pro-angiogenic genes VEGF, AKT, and HIF-1α. In addition, isopimpinellin exerts its anti-angiogenic effect through the regulation of miR-15b-5p and miR-542-3p. Furthermore, in zebrafish embryos, isopimpinellin inhibited the development of intersegmental vessels (ISVs) through the significant downregulation of all pro-angiogenic genes vegf, vegfr2, survivin, angpt-1, angpt-2, and tie-2.

CONCLUSION

Collectively, these experimental findings offer novel insights into the antiangiogenic nature of isopimpinellin and open new avenues for therapeutic approaches.

Root extract of water dropwort, Oenanthe javanica (Blume) DC, induces protein and gene expression of phase I carcinogen-metabolizing enzymes in HepG2 cells

Background

Cytochrome P450 (CYP) isoenzymes are an important phase I enzyme system. In the present study, we investigated the effects of Oenanthe javanica (Blume) DC on CYP1A1 and CYP1A2.

Findings

Whole plants were completely dried and then divided into leaves, stems, and roots for extraction. The human liver hepatocellular carcinoma cell line HepG2 was treated with ethanol extracts of these organs for 72 h and mRNA and protein expression levels were assessed. The root extract of O. javanica significantly elevated the expression of both CYP1A1 and CYP1A2 mRNAs (by 68 and 102 %, respectively). Similarly, the CYP1A1 and CYP1A2 protein levels were increased by the root extract (by 112 and 157 %, respectively). The effects of the root extract were much more pronounced than those of leaf and stem extracts. Subsequent GC–MS analysis revealed that the levels of major coumarin derivatives, xanthotoxin, bergapten, and isopimpinellin, were significantly higher in O. javanica root extracts than in leaf or stem extracts. Of note, 5 μM xanthotoxin (the most abundant furanocoumarin in O. javanica) induced the expression of CYP1A1 mRNA as well as CYP1A2 mRNA and protein, albeit the CYP1A1 protein level was elevated only at 10 μM xanthotoxin.

Conclusions

Although it is difficult to extrapolate such effects to metabolic outcomes because of the inherent limitations of in vitro experiments, it is important to note that dietary exposure to O. javanica may modulate phase I enzymes and thereby affect various xenobiotic metabolism.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-2078-8) contains supplementary material, which is available to authorized users.