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Aloe-emodin (AE) is one of the most important active components of Rheum officinale Baill. The present study aimed to investigate that AE could attenuate scopolamine-induced cognitive deficits via inhibiting acetylcholinesterase (AChE) activity and modulating oxidative stress. Kunming (KM) mice were received intraperitoneal injection of scopolamine (2 mg/kg) to induce cognitive impairment. Learning and memory performance were assessed in the Morris water maze (MWM). After behavioral testing, the mice were sacrificed and their hippocampi were removed for biochemical assays (superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), AChE and acetylcholine (ACh)). In vitro, we also performed the AChE activity assay and H₂O₂-induced PC12 cells toxicity assay. After 2 h exposure to 200 μM H₂O₂ in PC12 cells, the cytotoxicity were evaluated by cell viability (MTT), nitric oxide (NO)/lactate dehydrogenase (LDH) release and intracellular reactive oxygen species (ROS) production. Our results confirmed that AE showed significant improvement in cognitive deficit in scopolamine-induced amnesia animal model. Besides, it increased SOD, GPx activities and ACh content, while decreased the level of MDA and AChE activity in AE treated mice. In addition, AE was found to inhibit AChE activity (IC₅₀ = 18.37 μg/ml) in a dose-dependent manner. Furthermore, preincubation of PC12 cells with AE could prevent cytotoxicity induced by H₂O₂ and reduce significantly extracellular release of NO, LDH and intracellular accumulation of ROS. The study indicated that AE could have neuroprotective effects against Alzheimer's disease (AD) via inhibiting the activity of AChE and modulating oxidative stress.

Abstract: Ethnopharmacological relevance: Carthamus red isolated from safflower (Carthamus tinctorius L., a Chinese traditional medicine) is evaluated for antioxidant and hepatoprotective activity. Materials and methods: Carthamus red was isolated from a Na2CO3 extract of safflower and its analysis was carried out by HPLC/MS. Acute toxicity study was determined and the antioxidant activity was investigated using various established in vitro systems. An in vivo study against CCl4-induced liver injury was also conducted and compared with that of silymarin, a known hepatoprotective drug. Results: Carthamus red did not show any toxicity and mortality up to 2000mg/kg dose, and it showed strong antioxidant ability in vitro. In the in vivo study, carthamus red treatment lowered the serum levels of ALT, AST, ALP and total protein in liver damage rat models. Meanwhile, Nrf2, GSTα and NQO1 expressions were up-regulated at the protein level by carthamus red intervention. Additionally, the activities of antioxidant enzymes and level of GSH were elevated by carthamus red intervention, while the content of TBARS, which is an oxidative stress marker, was lessened. HE stain analysis showed that the condition of liver damage was mitigated. Conclusion: This study demonstrates that carthamus red may serve as a candidate with strong a hepatoprotective effect and antioxidant activity in liver damage. [Copyright &y& Elsevier]