Electroacupuncture Attenuates Immune-Inflammatory Response in Hippocampus of Rats with Vascular Dementia by Inhibiting TLR4/MyD88 Signaling Pathway.

OBJECTIVE: To investigate whether electroacupuncture (EA) alleviates cognitive impairment by suppressing the toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) signaling pathway, which triggers immune-inflammatory responses in the hippocampus of rats with vascular dementia (VaD). METHODS: The experiments were conducted in 3 parts and in total the Sprague-Dawley rats were randomly divided into 8 groups by a random number table, including sham, four-vessel occlusion (4-VO), 4-VO+EA, 4-VO+non-EA, sham+EA, 4-VO+lipopolysaccharide (LPS), 4-VO+LPS+EA, and 4-VO+TAK-242 groups. The VaD model was established by the 4-VO method. Seven days later, rats were treated with EA at 5 acupoints of Baihui (DV 20), Danzhong (RN 17), Geshu (BL 17), Qihai (RN 6) and Sanyinjiao (SP 6), once per day for 3 consecutive weeks. Lymphocyte subsets, lymphocyte transformation rates, and inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor α(TNF-α) were measured to assess immune function and inflammation in VaD rats. Transmission electron microscopy was used to observe the ultrastructure of nerve cells in the hippocampus. The levels of TLR4, MyD88, IL-6, and TNF-α were detected after EA treatment. TLR4/MyD88 signaling and cognitive function were also assessed after intracerebroventricular injection of TLR4 antagonist TAK-242 or TLR4 agonist LPS with or without EA. RESULTS: Compared with the 4-VO group, EA notably improved immune function of rats in the 4-VO+EA group, inhibited the protein and mRNA expressions of TLR4 and MyD88 in the hippocampus of rats, reduced the expressions of serum IL-6 and TNF-α (all P<0.05 or P<0.01), and led to neuronal repair in the hippocampus. There were no significant differences between the 4-VO+LPS+EA and 4-VO+EA groups, nor between the 4-VO+TAK-242 and 4-VO+EA groups (P>0.05). CONCLUSIONS: EA attenuated cognitive impairment associated with immune inflammation by inhibition of the TLR4/MyD88 signaling pathway. Thus, EA may be a promising alternative therapy for the treatment of VaD.

Chemical composition, antimicrobial activity and antioxidant activity of Litsea cubeba essential oils in different months.

In this study, the chemical composition, antimicrobial and antioxidant activities of Litsea cubeba essential oils extracted in different months were analysed. Results showed that the essential oil contents of fruits collected in June, July and August were 3.47%, 5.02% and 5.64%, respectively, and contained 13, 17 and 17 components, respectively. Neral and geranial were the main components and accounted for 54.76%. The essential oil extracted from fruits collected in July had the highest antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium, and it was the most effective based on the OH· scavenging activity test. The essential oil extracted from fruits collected in August was the most effective based on the test for DPPH· scavenging activity and ferric reducing antioxidant power. Considering the contents, chemical compositions and antimicrobial and antioxidant activities, the appropriate harvest time for L. cubeba essential oils is from July to August.