Metabolic profiles in plasma of patients with herpes labialis based on GC-MS.

OBJECTIVE: This study aims to compare the plasma metabolic profiles of patients with herpes labialis with healthy controls and identify the biomarkers of herpes labialis. SUBJECTS AND METHODS: We collected 18 patients with herpes labialis and 20 healthy individuals. Plasma samples from both groups were analyzed using gas chromatography-mass spectrometry (GC-MS). RESULTS: According to the principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), we found that metabolic profiles had changed in patients with herpes labialis compared to the controls. By further selecting the different metabolites according to the variable importance in the projection (VIP) and p valve of t-tests, we found that acetic acid, pyroglutamic acid, alanine, ethanedioic acid, cyclohexaneacetic acid, pyruvic acid, d-mannose, phosphoric acid, l-amphetamine, and citric acid were decreased in patients with herpes labialis, while sedoheptulose and ethylamine were increased. Pathway analysis showed that herpes labialis may affect the amino acid and energy metabolism. CONCLUSIONS: Our findings may contribute to elucidating the metabolic basis of herpes labialis and provide a new perspective for further research on the "Shang-Huo" state in traditional Chinese medicine (TCM).

Analysis of brain metabolites by gas chromatography-mass spectrometry reveals the risk-benefit concerns of prednisone in MRL/lpr lupus mice.

OBJECTIVE: Neuropsychiatric systemic lupus erythematosus (NPSLE) is a common cause of disability in systemic lupus erythematosus (SLE). This study aims to investigate the metabolic changes in the hypothalamus and frontal cortex in lupus-prone MRL/lpr mice. METHODS: Metabolic changes were analyzed using gas chromatography-mass spectrometry (GC-MS). RESULTS: According to the principal component analysis (PCA), the metabolic profiles were different between the frontal cortex and hypothalamus, but they were comparable between MRL/lpr and MRL/MpJ mice (16 weeks of age). By OPLS-DA, eight cortical and six hypothalamic differential metabolites were identified in MRL/lpr as compared to MRL/MpJ mice. Among these differential metabolites, we found a decrease of N-acetyl-L-aspartate (NAA, a potential marker of neuronal integrity), an increase of pyruvate and a decrease of glutamate in the frontal cortex but not in the hypothalamus. Prednisone treatment (3 mg/kg from 8 weeks of age) relieved the decrease of NAA but further increased the accumulation of pyruvate in the frontal cortex, additionally affected eight enriched pathways in the hypothalamus, and led to significant imbalances between the excitation and inhibition in both the frontal cortex and hypothalamus. CONCLUSION: These results suggest that the frontal cortex may be more preferentially affected than the hypothalamus in SLE. Prednisone disrupted rather than relieved metabolic abnormalities in the brain, especially in the hypothalamus, indicating that the risk-benefit balance of prednisone for SLE or NPSLE remains to be further evaluated.

A Transient Upregulation of Glutamine Synthetase in the Dentate Gyrus Is Involved in Epileptogenesis Induced by Amygdala Kindling in the Rat.

Reduction of glutamine synthetase (GS) function is closely related to established epilepsy, but little is known regarding its role in epileptogenesis. The present study aimed to elucidate the functional changes of GS in the brain and its involvement in epileptogenesis using the amygdala kindling model of epilepsy induced by daily electrical stimulation of basolateral amygdala in rats. Both expression and activity of GS in the ipsilateral dentate gyrus (DG) were upregulated when kindled seizures progressed to stage 4. A single dose of L-methionine sulfoximine (MSO, in 2 µl), a selective GS inhibitor, was administered into the ipsilateral DG on the third day following the first stage 3 seizure (just before GS was upregulated). It was found that low doses of MSO (5 or 10 µg) significantly and dose-dependently reduced the severity of and susceptibility to evoked seizures, whereas MSO at a high dose (20 µg) aggravated kindled seizures. In animals that seizure acquisition had been successfully suppressed with 10 µg MSO, GS upregulation reoccurred when seizures re-progressed to stage 4 and re-administration of 10 µg MSO consistently reduced the seizures. GLN at a dose of 1.5 µg abolished the alleviative effect of 10 µg MSO and deleterious effect of 20 µg MSO on kindled seizures. Moreover, appropriate artificial microRNA interference (1 and 1.5×10(6) TU/2 µl) of GS expression in the ipsilateral DG also inhibited seizure progression. In addition, a transient increase of GS expression and activity in the cortex was also observed during epileptogenesis evoked by pentylenetetrazole kindling. These results strongly suggest that a transient and region-specific upregulation of GS function occurs when epilepsy develops into a certain stage and eventually promotes the process of epileptogenesis. Inhibition of GS to an adequate degree and at an appropriate timing may be a potential therapeutic approach to interrupting epileptogenesis.

Chronic h1-antihistamine treatment increases seizure susceptibility after withdrawal by impairing glutamine synthetase.

AIM: To investigate the effect of chronic H1-antihistamine treatment on seizure susceptibility after drug withdrawal in nonepileptic rats and to further study its relation to glutamine synthetase (GS), which is the key enzyme for glutamate metabolism and gamma aminobutyric acid (GABA) synthesis. METHODS: After drug withdrawal from a 2-week treatment with diphenhydramine or pyrilamine, seizure susceptibility was determined by amygdaloid kindling or pentylenetetrazol model; meanwhile, the GS expression or activity was analyzed. The glutamine, glutamate, and GABA contents were measured by high-performance liquid chromatography. RESULTS: Seizure susceptibility significantly increased in amygdaloid kindling and pentylenetetrazol model 10 days after drug withdrawal from a 2-week treatment with H1-antihistamines. Meanwhile, GS activity and expression in the cortex or hippocampus decreased simultaneously with a marked decline of glutamine and GABA content. Comparable inhibition of GS activity by methionine sulfoximine was also sufficient to increase the susceptibility, while supplementation with glutamine reversed the high susceptibility 10 days after diphenhydramine withdrawal. Moreover, the seizure susceptibility increased 10 days after diphenhydramine withdrawal in wild-type mice but not in histidine decarboxylase knockout mice, which lack histamine. CONCLUSIONS: Chronic H1-antihistamine treatment produces long-lasting increase in seizure susceptibility in nonepileptic rodents after drug withdrawal and its mechanism involves impairment of GS through blocking the action of histamine.

Relative contribution of small and large intestine to deglycosylation and absorption of flavonoids from Chrysanthemun morifolium extract.

The flower of Chrysanthemum morifolium Ramat (CM) is an established part of traditional Chinese medicine (TCM). Luteolin and apigenin flavonoids are the effective components of the CM extract (CME); however, they exist in the orally consumed CME as glycosides. The present study was carried out to determine the relative contribution of the small and large intestine to the deglycosylation and absorption of flavonoids from CME using a rat model system. The distribution of luteolin and apigenin in rat gastrointestinal (GI) luminal contents, tissues, and plasmas was assessed after the oral administration of CME. The hydrolysis and absorption of CME flavonoids in different rat GI segments were further evaluated by using in situ ligated models and cell-free extracts prepared from rat GI segments. The results demonstrated that after the oral administration of CME, the magnitude of deglycosylation in rats was surprisingly high (about 30%) in the stomach and upper intestine within the first 5 min after ingestion, and early absorption in the plasma was detected. The results from site-limited administration revealed that the stomach was the initial hydrolysis site, while the duodenum was the first effective absorption site for CME flavonoids. Diminishing microbial flora in the jejunum had no significant effect on the hydrolysis of the flavonoids from CME, but the cell-free extracts prepared from rat GI segments demonstrated a strong ability to hydrolyze. Taken together, our findings suggest that enteric disposition contributes to the pharmacokinetics of luteolin and apigenin after oral administration of CME. Moreover, the upper digestive tract plays a key role in the hydrolysis and absorption of flavonoids in CME.

Therapeutic time window of low-frequency stimulation at entorhinal cortex for amygdaloid-kindling seizures in rats.

The present study was designed to determine whether low-frequency stimulation (LFS) of the entorhinal cortex(EC) has an anticonvulsive effect, and whether LFS delivered at different times plays different roles. We found that LFS of the EC immediately or 4 s after kindling stimulation had an anticonvulsive effect, and that the latter had a better effect on both kindling and kindled seizures. However, LFS delivered after the cessation of afterdischarge or 10 s after the kindling stimulation, augmented the epileptic activity. So the EC is a potential target for LFS to interfere with epilepsy. Our findings suggest that even in the duration of afterdischarge, there exists a "time window" for LFS treatment, indicating that the time delay of closed-loop stimulation is crucial for LFS treatment.

Mode-dependent effect of low-frequency stimulation targeting the hippocampal CA3 subfield on amygdala-kindled seizures in rats.

Brain stimulation with low-frequency stimulation (LFS) is emerging as an alternative treatment for refractory epilepsy. The present study aimed to investigate the effects of LFS targeting the hippocampal CA3 subfield in different modes on amygdala-kindled seizures in Sprague-Dawley rats. When fully kindled seizures were achieved by daily electrical stimulation of the amygdala, LFS (15 min train of 0.1 ms pulses at 1 Hz and 100 microA) of the CA3 was applied in several modes. Post-treatment with LFS significantly reduced the severity of and susceptibility to evoked seizures, whereas pre-treatment with LFS resulted in a similar but much weaker inhibition of seizures. Interestingly, prior consecutive daily application of LFS in the absence of kindling stimulation did not reduce subsequent evoked seizures, but abolished the anti-epileptic effect of post-treatment. These results indicated that LFS of the CA3 is able to reduce kindled seizures in a mode-dependent manner without cumulative feature. The hippocampal CA3 subfield could be considered as a potential target for epilepsy treatment using LFS, and should be delivered in an appropriate stimulation mode.