Lipid-accumulated reactive astrocytes promote disease progression in epilepsy.

Reactive astrocytes play an important role in neurological diseases, but their molecular and functional phenotypes in epilepsy are unclear. Here, we show that in patients with temporal lobe epilepsy (TLE) and mouse models of epilepsy, excessive lipid accumulation in astrocytes leads to the formation of lipid-accumulated reactive astrocytes (LARAs), a new reactive astrocyte subtype characterized by elevated APOE expression. Genetic knockout of APOE inhibited LARA formation and seizure activities in epileptic mice. Single-nucleus RNA sequencing in TLE patients confirmed the existence of a LARA subpopulation with a distinct molecular signature. Functional studies in epilepsy mouse models and human brain slices showed that LARAs promote neuronal hyperactivity and disease progression. Targeting LARAs by intervention with lipid transport and metabolism could thus provide new therapeutic options for drug-resistant TLE.

Different influences on tacrolimus pharmacokinetics by coadministrations of zhi ke and zhi shi in rats.

Tacrolimus, an immunosuppressant with narrow therapeutic window, has been used widely in transplant patients. Grapefruit juice and pomelo have been reported to increase the blood levels of tacrolimus. Zhi Ke and Zhi Shi, the ripe peels and unripe fruits of Citrus aurantium which is chemotaxonomically related to grapefruit and pomelo, are in wide use in clinical Chinese medicine. To investigate the possible interaction of these two Citrus herbs with tacrolimus, male Sprague-Dawley rats were orally given tacrolimus (1.5 mg/kg) with and without Zhi Ke and Zhi Shi decoctions in a cross-over design. Blood samples were withdrawn via cardiopuncture at specific time and quantitated by a microparticle enzyme immunoassay. In addition, to explore the mechanism of interaction, LS 180 cell line was used for the transport study of rhodamine 123, a typical substrate of P-glycoprotein (P-gp). The results showed that Zhi Shi significantly decreased the C(max) and AUC(0-t) of tacrolimus by 72.4% and 72.0%, respectively, whereas Zhi Ke did not affect tacrolimus pharmacokinetics. LS 180 cell line study indicated that Zhi Shi increased the efflux activity of P-gp, enabling us to explain the decreased oral bioavailability of tacrolimus caused by Zhi Shi. Hence, we suggest that Zhi Shi be contraindicated for transplant patients treated with tacrolimus to reduce the risk of allograft rejection.

Tissue distribution of naringenin conjugated metabolites following repeated dosing of naringin to rats.

Background: Naringin is a major antioxidant in Citrus fruits and herbs. To clarify molecular forms distributed to various tissues, we investigated tissue distribution of naringin and relevant metabolites in rats after repeated dosing. Methods: Male Sprague-Dawley rats were orally administered naringin (210 mg/kg) twice daily for eight days. At 6 h post the 17th dose, various tissues including liver, kidney, heart, spleen and brain were collected and analyzed by HPLC method before and after hydrolysis with ß-glucuronidase and sulfatase, individually. Results: The free forms of naringin and naringenin were not detected in all the tissues assayed. Liver contained the highest concentration of naringenin sulfates, followed by spleen, heart, brain and kidney. Naringenin glucuronides were present in liver and kidney, but not in spleen, brain and heart. Conclusion: The bioavailability of naringenin glucuronides and sulfates supported its application for personalized medicine.

Citrus grandis peel increases the bioavailability of cyclosporine and tacrolimus, two important immunosuppressants, in rats.

Citrus grandis peel (CGP) is a beverage ingredient and a medicinal herb in Oriental countries. Cyclosporine and tacrolimus, important immunosuppressants with narrow therapeutic windows, are widely used in transplant patients. This study investigated the effects of co-administering CGP on the bioavailability of cyclosporine and tacrolimus. Male Sprague-Dawley rats were orally administered tacrolimus or cyclosporine with and without CGP. The concentrations of cyclosporine and tacrolimus in blood were assayed by monoclonal fluorescence polarization immunoassay and microparticle enzyme immunoassay, respectively. P-glycoprotein- and cytochrome P 450 3A4 (CYP3A4)-associated mechanisms were investigated by using everted rat intestinal sac and recombinant CYP3A4 isozyme. The results showed that CGP significantly increased the bioavailability of cyclosporine and tacrolimus by 100.0% and 234.7%, respectively. Ex vivo studies indicated that the interaction was mediated by the inhibition of CYP3A4. We suggest that CGP is contraindicated for transplant patients treated with cyclosporine or tacrolimus to minimize the risk of intoxication.