28-Day Oral Chronic Toxicity Study of Arctigenin in Rats.

Arctium lappa (burdock) is the most popular daily edible vegetable in China and Japan because of its general health tonic effects. Previous studies focused on the beneficial role of Arctigenin but neglected its potential side-effects and toxicities. In the present study, the sub-chronic toxicity profile of Arctigenin following 28 days of consecutive exposure was investigated in rats. The results showed that during the drug exposure period, Arctigenin-12 mg/kg administration resulted in focal necrosis and lymphocytes infiltration of heart ventricular septal muscle cells. In the kidney cortical zone, the renal tubular epithelial cells were swollen, mineralized, and lymphocyte infiltrated. In the liver, the partial hepatocyte cytoplasm showed vacuolation and fatty changes, focal necrosis, and interstitial lymphocyte infiltration. In the rats that underwent 36 mg/kg/day administration, there was bilateral testis and epididymis atrophy. In the lung and primary bronchus, erythrocytes and edema fluid were observed. Changes of proestrus or estrus were observed in the uterus, cervix, and vagina intimal epithelial cells. Lymphocytic focal infiltration occurred in the prostate mesenchyme. The high dosage of Arctigenin only decreased the body weight at day 4. At the end of the recovery period, histopathological changes were irreversible, even after withdrawal of the drug for 28 days. Focal necrosis still existed in the heart ventricular septal muscle cells and hepatocytes. Lymphocyte infiltrations were observed in the heart, renal cortex, hepatocyte, and pancreas exocrine gland. Meanwhile, atrophy occurred in the testicles and pancreas. In addition, in the Arctigenin-12 mg/kg group, creatinine (CREA) and brain weight were both significantly increased. The toxicokinetical study demonstrated that Arctigenin accumulated in the organs of rats. The food consumption, hematological, and biochemical parameters were not associated with the above results. These contradictory results might result from the lesions induced by Arctigenin, which were not sufficiently serious to change the parameters. These results suggest that Arctium lappa should be consumed daily with caution because of the potential toxicity induced by Arctigenin. According to all results, the lowest observed adverse effect level (LOAEL) was induced by 12 mg/kg daily exposure to Arctigenin, and the No-observed-adverse-effect-level (NOAEL) should be lower than 12 mg/kg.

Icaritin Improves Antibody-Induced Thrombocytopenia in a Mouse Model by Regulating T-cell Polarization.

Previous studies have shown that icaritin (ICT) has significant protective effects on immune thrombocytopenia (ITP), and the present study aimed to discuss the mechanism of this protective effect from the aspect of regulating T-cell polarization by an antibody-induced ITP mice model. Mice were given rat anti-mouse CD41 antibody (MWReg30) by intraperitoneal injection for 7 d to produce ITP model. At the same time, ICT was administrated at 10 mg/kg/d orally for 9 d. Peripheral blood platelets were counted by hematology analyzer. Spleen index was also tested. Spleen T-helper cell (Th), cytotoxic T-cell (CTL), Th1, Th2, Th17, regulatory T-cell (Treg), and follicular helper T-cell (Tfh) were quantified by flow cytometry. Serum Th1/Th2/Th17 cytokines were tested by mouse Th1/Th2/Th17 cytometric bead array (CBA) kit and transforming growth factor beta (TGF-ß) were analyzed by enzyme-linked immunosorbent assay (ELISA) kit. The results indicated that ICT (10 mg/kg) protected against MWReg30-induced ITP, as evidenced by increased blood platelets and decreased spleen index. In addition, the imbalance of Th/CTL in ITP mice spleen was regulated by ICT. Meanwhile, ICT inhibited Th1, Th17, and Tfh and improved Th2 and Treg in ITP mice spleen. Furthermore, the results of CBA and ELISA suggested that ICT decreased serum Th1- and Th17-related cytokines and increased Th2 cytokines, as well as promoted the release of TGF-ß. These results demonstrated that the protective effect of ICT on ITP was mediated by regulating T-cell polarization.

[Effects of serum derived from rats undergone auricular acupuncture intervention on expression of TNF-alpha mRNA, cell adhesion factor-1 and vascular intercellular adhesion molecule-1 proteins of incubated cerebral microvascular endotheliocytes with diabetic injury].

OBJECTIVE: To observe the protective effect of serum derived from rats undergone auricular electroacupuncture (EA) stimulation on the incubated cerebral microvascular endotheliocytes with diabetic injury so as to investigate the underlying mechanism of cholinergic anti-inflammatory action. METHODS: SD rats were randomized into normal group (n = 10), diabetic model group (n = 6), auricular EA group (n = 8), vagotomy + EA group (n = 7, received ipsilateral vagotomy before auricular EA stimulation), atropine + EA group (n = 8), hexamethonium + EA group (n = 7) and alpha-bungarotoxin + EA group (n = 7). Diabetic mellitus model was established by feeding the rats with high sugar, high fat forage and intraperitoneal injection of 1% streptozotocin injection (STZ, 35 mg/kg). EA was applied to ipsilateral "Yi-Dan"-point and "Er-Shenmen" for 30 min, once daily for 10 days. Atropine (0.1 mg/kg, an anticholinergic drug), hexamethonium (10 mg/kg, an antagonist of the nicotinic acetylcholine receptors located in sympathetic and parasympathetic ganglia) and alpha-bungarotoxin (1.0 microg/kg, a type of alpha-neurotoxin that is known to bind irreversibly and competitively to the nicotinic acetylcholine receptors) were given to the rats by tail venous injection, respectively, before ipsilateral auricular EA intervention, once daily for 10 days. Blood samples from rats of each group were then collected. Normally cultured rat brain microvascular endotheliocytes were randomly divided into the same 7 groups. The diabetic-like damage model of cerebral microvascular endotheliocytes was established in the 6 groups except the normal group by adding the fluid containing glucose (20 mmol/L), insulin (100 mU/L) and oxidized low density lipoprotein (200 mg/L) to the culture medium. After 48 hours' incubation, the conditional culture solutions were collected for filtration and degerming. Morphological changes and cellular ultra-microstructure were examined using light microscope and transmission electron microscope, respectively. Tumor necrosis factor-alpha (TNF-alpha) mRNA expression of the cultured microvascular endotheliocytes was assayed using RT-PCR, and the soluble cell adhesion factor-1 (sICAM-1) and soluble vascular intercellular adhesion molecule-1 (sVCAM-1) concentrations in 1 mL culture fluid were measured using ELISA. RESULTS: Compared to the normal control group, the cultured cerebral microvascular endotheliocytes in the model group displayed a cluster-like or floating state, enlargement of the space, and increase of refractivity under light microscope, and showed swelling of the mitochondria with broken cristae and expansion of the space and even with membrane fusion or disappearance under electron microscope. This situation was relatively lighter in both auricular EA and atropine groups, and severe in the vagotomy, hexamethonium and alpha-bungarotoxin groups. TNF-alpha mRNA expression and sICAM-1 and sVCAM-1 concentrations were significantly higher in the model group than in the normal group, but significantly lower in both auricular EA group and atropine group than in the model group (P < 0.01, P < 0.05). No remarkable diffe-rences were found among the model, vagotomy, hexamethonium and alpha-bungarotoxin groups in the levels of TNF-alpha mRNA expression and sICAM-1 and sVCAM-1 concentrations (P > 0 05). CONCLUSION: Auricular EA intervention rat serum can lighten diabetic cellular injury, suppress TNFalpha mRNA expression and reduce ICAM-1 and sVCAM-1 concentrations of rat cerebral microvascular endotheliocytes, which is closely associated with the intact vagus nerve and normal nicotinic acetylcholine receptors in rats.