Modulation of the immune system has recently been shown to be involved in the pharmacological effects of old antiepileptic drugs and in the pathogenesis of epilepsy. Therefore, the most recent guidelines for immunotoxicological evaluation of drugs were consulted to investigate the immunomodulatory effects of lamotrigine, a newer antiepileptic drug, in BALB/c mice. These included the in vivo effects of lamotrigine on delayed-type hypersensitivity (DTH) response to sheep red blood cell (SRBC) antigens, hemagglutination titer assays and hematological changes. In vitro effects of lamotrigine on ConA-induced splenocyte proliferation and cytokine secretion were assessed. The results showed that lamotrigine treatment significantly increased the DTH response to SRBC in the mouse model of this study. This was accompanied by a significant increase in relative monocyte and neutrophil counts and in spleen cellularity. Lamotrigine significantly inhibited ConA-induced splenocyte proliferation in vitro and it significantly inhibited IL-2 and TNF-α secretion in ConA-stimulated splenocytes. In conclusion, the results demonstrated significant immunomodulatory effects of lamotrigine in BALB/c mice. These data could expand the understanding of lamotrigine-induced adverse reactions and its role in modulating the immune system in epilepsy.

Marrubium vulgare (Lamiaceae) is frequently used in traditional medicine to treat many illnesses from ancient times. Its beneficial effects include antibacterial, antioedematogenic, and analgesic activities. This study was designed to evaluate the antioxidant and anti-inflammatory activities of organic and aqueous extracts of the leaves, the flowers, the stems, and the roots of Marrubium vulgare. The total phenolic and flavonoid contents as well as the antioxidant and the anti-inflammatory effects of methanol, chloroform, ethyl acetate, and aqueous extracts have been investigated by using different in-vitro methods. It was found that the ethyl acetate extract from Marrubium vulgare stems had the highest total phenolic content, while the ethyl acetate extract from the leaves yielded a high concentration of flavonoids. The ethyl acetate extract from the stems exhibited the highest activity in scavenging of 2,2-diphenyl- 1-picrylhydrazyl (DPPH), as well as in protecting erythrocytes. The leaves aqueous extract exhibited the highest ferrous chelating activity and its methanolic extract was found to be the strongest inhibitor of lipid peroxidation in β-carotene bleaching assay. The leaves chloroform extracts as well as the flowers methanol, chloroform, and ethyl acetate extracts were found to decrease the pro-inflammatory tumor necrosis factor alpha (TNF-α) cytokine levels in a dose-dependent manner. On the other hand, the flowers methanolic extract and the leaves methanol, ethyl acetate, and aqueous extracts decreased the interleukin-1 beta (IL- 1β) release. It was also found that the methanol extract from the flowers and the chloroform extract from the stems of Marrubium vulgare inhibited interleukin-8 (IL-8) release. This study provides a scientific basis for the traditional use of Marrubium vulgare as an anti-inflammatory agent and for the plant to be considered as an important resource of natural antioxidants.

Tigecycline is a glycylcycline antibiotic approved by the FDA for the treatment of complicated infections. Despite its effectiveness, the FDA announced a warning of increasing mortality associated with its use. There is, however, no clear explanation for this side effect. Previous reports found a possible effect of tigecycline on leukocyte proliferation and proinflammatory cytokine release. We t herefore i nvestigated the effect of tigecycline on the immune components and response in Balb/c mice in vivo and in vitro. It was found that tigecycline enhanced lymphocyte proliferation and significantly increased cellular infiltration within the footpad, as based on DTH testing, but reduced the hemagglutination titer. In splenocyte cultures, tigecycline suppressed splenocyte proliferation with IC50 3-5 mmol L-1, significantly increased IL-2 secretion and reduced IL-17 secretion in a dose dependent mode. In conclusion, tigecycline is safe at therapeutic and sub-therapeutic doses, but it could still have an immunomodulatory effect at higher doses. Use of higher doses of tigecycline requires further investigation.