Oral magnesium prevents acetaminophen-induced acute liver injury by modulating microbial metabolism.

Acetaminophen overuse is a common cause of acute liver failure (ALF). During ALF, toxins are metabolized by enzymes such as CYP2E1 and transformed into reactive species, leading to oxidative damage and liver failure. Here, we found that oral magnesium (Mg) alleviated acetaminophen-induced ALF through metabolic changes in gut microbiota that inhibit CYP2E1. The gut microbiota from Mg-supplemented humans prevented acetaminophen-induced ALF in mice. Mg exposure modulated Bifidobacterium metabolism and enriched indole-3-carboxylic acid (I3C) levels. Formate C-acetyltransferase (pflB) was identified as a key Bifidobacterium enzyme involved in I3C generation. Accordingly, a Bifidobacterium pflB knockout showed diminished I3C generation and reduced the beneficial effects of Mg. Conversely, treatment with I3C or an engineered bacteria overexpressing Bifidobacterium pflB protected against ALF. Mechanistically, I3C bound and inactivated CYP2E1, thus suppressing formation of harmful reactive intermediates and diminishing hepatocyte oxidative damage. These findings highlight how interactions between Mg and gut microbiota may help combat ALF.

[Effect of electroacupuncture on insulin sensitivity and TLR4/ IκBα/ NF-κB signaling in hypothalamus of obese rats with insulin resistance].

OBJECTIVE: To observe the effects of electroacupuncture on the hypothalamic Toll-like receptor 4 (TLR4)/ inhibitor nuclear factor kappa-B α(IκBα)/nuclear factor-κB (NF-κB) signaling pathway in obese insulin resistance (OIR) rats，so as to explore the mechanism of EA underlying improving of insulin resistance. METHODS: Rats were randomly divided into normal, model and EA groups, with 8 rats in each group. The rat model of OIR was established by feeding with high-fat diet for 8 weeks. EA(2 Hz，1 mA)was applied to unilateral"Zusanli"(ST36),"Fenglong"(ST40),"Zhongwan"(CV12)and"Guanyuan"(CV4)for 10 min, 3 times a week for 8 weeks. The body mass, fasting blood glucose(FBG) and postprandial blood glucose (PBG) were measured before and after 2、4、6、8 weeks' intervention. An intraperitoneal injection glucose tolerance test and hyperglycemic clamps were applied to test insulin resistance. The expression of TLR4、p-IκBα、NF-κB p65、TNF-α、IL-1ß mRNA and protein in hypothalamus was detected by quantitative real-time PCR and Western blot, separately. RESULTS: Compared with the normal group, the body mass and PBG of the model group were significantly increased (P<0.01); glucose infusion rate(GIR) was significantly reduced (P<0.01); in the IPGTT test, the increase in blood glucose was significantly greater after 90 and 120 min of glucose injection(P<0.01); the hypothalamus TLR4, NF-κB p65，p-IκBα, TNF-α, IL-1ß mRNA and protein expressions were all significantly increased (P<0.01). After EA intervention, the body weight and PBG were significantly down-regulated after 6 weeks and 2 weeks of intervention (P<0.05, P<0.01); GIR were significantly up-regulated after 8 weeks of intervention (P<0.05); In the IPGTT test, the increase in blood glucose 60 min after glucose injection was significantly down-regulated (P<0.05); hypothalamus TLR4, NF-κB p65，p-IκBα, TNF-α, IL -1ß mRNA and protein expression were significantly down-regulated (P<0.01). CONCLUSION: EA can reduce the body weight of OIR rats and improve IR, which may be related to down-regulating the hypothalamic TLR4/IκBα/NF-κB signaling pathway.

[Effects of electroacupuncture on inflammatory response and intestinal mucosal barrier in obese rats with insulin resistance].

OBJECTIVE: To observe the effects of electroacupuncture (EA) on inflammatory response and intestinal mucosal barrier in obese rats with insulin resistance, and to explore the mechanism of EA on improving insulin resistance in rats. METHODS: Among 45 Wistar male rats, 15 rats were randomly selected and fed with common diet. After eight weeks, 10 rats were randomly selected and divided into the normal group. The remaining 30 rats were fed with high-fat diet for 8 weeks to establish obesity model of rat, among 28 rats with successful model of obesity, 20 rats were randomly selected and divided into the model group and EA group, 10 rats in each one. At the same time, 3 rats in the model group and the EA group were randomly selected for hyperinsulinemia-euglycemic clamp operation to determine whether the insulin resistance model was successful. After model establishment, the rats in the EA group were intervented with EA at "Zhongwan" (CV 12), "Guanyuan" (CV 4), "Zusanli" (ST 36) and "Fenglong" (ST 40) with continuous wave, frequency of 2 Hz and intensity of 1 mA; "Zusanli" (ST 36) and "Fenglong" (ST 40) were used alternately on both sides; the needles were sustained for 10 min; EA was given once every other day, three times a week for a total of 8 weeks. During the intervention, the rats in the normal group and the model group were fixed but not intervented. The body mass and postprandial blood sugar were measured in each group before and after 8-week intervention. After 6-week intervention, 3 rats in each group were clamped to detect systemic insulin sensitivity. Before the rats were killed, blood was taken from the apex of the heart to detect the serum insulin content. After the rats were killed, the mRNA levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in liver and adipose tissue and occlidin and ZO-1 in colon tissue were detected by Real time-PCR; the protein expression levels of occludin and ZO-1 in colon tissue were detected by Western blot method. RESULTS: Compared with the normal group, the body mass, postprandial blood sugar and serum insulin content in the model group were increased significantly, the glucose infusion rate (GIR) was decreased significantly (all P<0.01), the mRNA expressions of TNF- and IL-6 in liver and adipose tissue were increased (P<0.05, P<0.01), the mRNA and protein expressions of ZO-1 in colon tissue were decreased significantly (both P<0.01), and the mRNA expression of occludin was significantly decreased (P<0.01). Compared with the model group, the body mass, postprandial blood sugar, serum insulin content, mRNA expressions of TNF-a and IL-6 in liver and adipose tissue were significantly decreased (P<0.01, P<0.05), GIR was significantly increased (P<0.01), and the mRNA and protein expressions of ZO-1 in colon tissue were increased (P<0.01, P<0.05). CONCLUSION: EA could decrease blood sugar and increase insulin sensitivity. Its mechanism may be related to inhibiting the expression of inflammatory factors and improving intestinal mucosal barrier.

Acupuncture and moxibustion reduces neuronal edema in Alzheimer's disease rats.

To examine the possible correlation of aberrant Wnt signaling and pathological changes in Alzheimer's disease, we established a rat model of Alzheimer's disease and measured axin and ß-catenin expression in the hippocampus. Rats were pretreated with moxibustion or electroacupuncture, or both, at Baihui (GV20) and Shenshu (BL23). Axin expression was lower, ß-catenin expression was greater, and neuronal cytoplasmic edema was visibly prevented in the rats that had received the pretreatments. Our results suggest that the mechanism underlying the neuroprotective effect of acupuncture and moxibustion in Alzheimer's disease is associated with axin and ß-catenin expression in the Wnt signal transduction pathway.

[Effects of electroacupuncture on microvascular ultrastructure and VEGF expression of the right cerebral cortex in focal cerebral ischemia/reperfusion injury rats].

OBJECTIVE: To study the protective effects of electroacupuncture (EA) on the cortical microvasculature in rats with focal cerebral ischemia/reperfusion injury (CI/RI). METHODS: Eighty SD rats were randomly divided into: normal group (n = 8), sham-operation (sham) group (n = 8), model group (n = 32) and EA group (n = 32). The II/II model was established by occlusion of the middle cerebral artery for 30 min and reperfusion for 1 day (d), 2 d, 4 d and 8 d respectively. EA was applied to "Baihui" (GV20), "Shuigou" (GV 26) and bilateral "Zusanli" (ST 36) areas for 30 min, once daily for 1 d, 2 d, 4 d and 8 d. The right cortical microvascular ultrastructure was examined with transmission electron microscopy and cerebral vascular endothelial growth factor (VEGF) mRNA expression was detected by quantitative real-time PCR. RESULTS: The microvascular ultrastructure of the right cerebral cortex was severely injured in rats of the model group whereas greatly improved in rats of EA group. VEGF mRNA expression of the right cerebral cortex was increased significantly in the model group (P < 0.05, P < 0.01) and further upregulated in the EA group (P < 0.01). CONCLUSION: EA intervention can alleviate the injury of microvascular ultrastructure of focal ischemic cerebral tissue and upregulate cerebral VEGF mRNA expression, suggesting a role of EA in protecting the ischemic brain tissues by facilitating the angiogenesis of capillary vessels and the function reconstruction of the damaged microvasculature.

[Effect of electroacupuncture of different acupoints on the excitability of detrusor muscle and the expression of BDNF and TrkB in the spinal cord of rats with urinary retention due to spinal cord injury].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of different acupoints on the expression of brain-derived neurotrophic factor (BDNF) and tropomyosine receptor kinase B (TrkB) in the spinal cord and the excitability of detrusor muscle of the uninary bladder in rats with urinary retention owing to spinal cord injury (SCI). METHODS: A total of 100 female SD rats were randomly divided into normal, sham-operation (sham), model, EA-Guanyuan (CV 4), and EA-Shuidao (ST 28) groups, with 20 cases in each. SCI induced urinary retention model was established by using weight dropping method. EA (1 mA, 2 Hz/15 Hz) was applied to "Guanyuan" (CV 4) and "Shuidao" (ST 28) respectively for 20 min, once a day for 10 days. The excitability (tone, contraction frequency) of the detrusor muscle of the bladder was detected in vitro by using electrophysiological method, and the expression of BDNF and TrkB in spinal cord was determined by immunohistochemistry staining. RESULTS: In comparison with normal control and sham groups, the tension and the contraction frequency of detrusor muscle in model group lowered significantly (P<0.05), while compared with model group, both the tension and contraction frequency of detrusor muscle increased pronouncedly in EA-CV 4 and EA-ST 28 groups (P<0.05), and the effect of EA-CV 4 was apparently superior to that of EA-ST 28 (P<0.05). In comparison with normal and sham groups, the BDNF and TrkB immunoreaction positive cells in the spinal cord were significantly more in model group (P<0.05). Compared with model group, those of EA-CV 4 and EA-ST 28 groups were obviously further increased (P<0.05), and the effect of EA-CV 4 group was markedly superior to that of EA-ST 28 group (P<0.05). CONCLUSION: EA of CV 4 and ST 28 can raise the excitability of the smooth muscle of the uninary bladder in rats with SCI-induced urinary retention, which may be related to its effects in upregulating the expression of BDNF and TrkB in the spinal cord. The effects of EA of CV 4 were evidently superior to those of EA of ST 28.