Yuk-Mi-Jihwang-Tang, a Traditional Korean Multiple Herbal Formulae, Improves Hippocampal Memory on Scopolamine Injection-Induced Amnesia Model of C57BL/6 Mice

Pharmacological Effects of Gami-Yukmijihwang-Tang on the Lipopolysaccharide-Induced Hippocampus Oxidation and Inflammation via Regulation of Sirt6

Yukmijihwang-Tang is widely used in traditional Korean medicine to treat age-related disorders. In the present study, we re-prescribed Gami-Yukmijihwang-Tang (YJT), which is slightly modified from Yukmijihwang-Tang by adding more medicinal plants to evaluate its pharmacological effects on underlying mechanisms against repeated lipopolysaccharide (LPS)-injection-induced neuroinflammation in the hippocampus regions. C57BL/6J male mice (16–24 weeks old) were divided into six groups: (1) the control group (DW with 0.9% saline injection), (2) LPS group (DW with LPS injection), YJT groups ((3) 100, (4) 200, or (5) 400 mg/kg of YJT with LPS injection), and (6) glutathione (GSH) group (100 mg/kg of GSH with LPS injection), respectively. Mice were orally administrated with various doses of YJT or glutathione (GSH) for the first five days. Neuroinflammation in the hippocampus region was induced by repeated injection of LPS during the last three days. As predicted, LPS not only increased oxidative stress–related markers including malondialdehyde, 4-hydroxynonenal, nitrotryptophan, and hydrogen peroxide, but also drastically enhanced inflammatory reactions including nitric oxide, inducible nitric oxide synthase, p65, and toll-like receptor 4, respectively. YJT administration, on the other hand, notably decreased the above pathological alterations by enhancement of antioxidant capacities such as superoxide dismutase and catalase activities. To explain the underlying pharmacological actions of YJT, we focused on a representative epigenetic regulator, a nicotinamide adenine dinucleotide + (NAD+)–dependent chromatin enzyme, Sirtuin 6 (Sirt6). Neuroinflammation in hippocampus regions depleted Sirt6 at the protein level and this alteration directly affected the nuclear factor erythroid 2–related factor (Nrf2)/hemeoxygenase (HO)-1 signaling pathway in the LPS group; however, YJT significantly recovered the Sirt6 protein levels, and it could recover the abnormal status of Nrf2/HO-1 signaling pathways in the hippocampus regions. Additionally, Sirt6 led to the up-regulation of GSH sub-enzymes of mRNA expression and protein levels of total GSH content. These findings suggest that YJT can protect against LPS-induced neuroinflammation and oxidative stress by regulating the Sirt6-related pathways and normalizing the GSH redox cycle.

Efficacy of Yukmijihwang-tang on symptoms of Alzheimer disease: A protocol for systematic review and meta-analysis

BACKGROUND

Alzheimer disease (AD) is the most common cause of dementia, which may lead to severe memory loss and other cognitive disorders. Yukmijihwang-tang (YMJ), a type of Korean traditional herbal medicine, has been shown to be effective against neurodegenerative diseases. Although a meta-analysis on the efficacy of YMJ on AD exists, the study had some limitations, and there have been several newly published studies assessing the effect of YMJ. Therefore, the purpose of this study is to evaluate the efficacy and safety of YMJ as a treatment for AD through a meta-analysis.

METHODS

A systematic search of the following electronic databases will be conducted to identify eligible studies: MEDLINE (PubMed), Elsevier (EMBASE), The Cochrane Central Register of Controlled Trials (CENTRAL), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Korean Medical Database (KMBASE), Oriental Medicine Advanced Searching Integrated System (OASIS), Korean Traditional Knowledge Portal, Citation Information by NII (CiNii), China National Knowledge Infrastructure (CNKI). All randomized controlled trials assessing the efficacy and safety of YMJ on the symptoms of AD will be included. Two independent reviewers will perform article retrieval, deduplication, data screening, data extraction, quality evaluation, and data analyses using RevMan version 5.4. The Cochrane risk of bias tool will be used to assess the quality of the trials.

RESULTS

This study will provide synthesis of the cognitive function measured with neuropsychological tests, behavioral and psychological symptoms of dementia (BPSD), and activities of daily living (ADL) measured using validated scales. The clinical effective rate and adverse events will also be analyzed to assess the efficacy and safety of YMJ for treating AD.

CONCLUSION

This systematic review will provide evidence for the efficacy and safety of YMJ in AD.

ETHICS AND DISSEMINATION

Ethical approval is not required because individual patient data will not be included in this study. The study findings will be disseminated through conference presentations.

Walnut Oil Prevents Scopolamine-Induced Memory Dysfunction in a Mouse Model

For thousands of years, it has been widely believed that walnut is a kind of nut that has benefits for the human body. Walnut oil, accounting for about 70% of walnut, mainly consists of polyunsaturated fatty acids. To investigate the effect of walnut oil on memory impairment in mice, scopolamine (3 mg/kg body weight/d) was used to establish the animal model during Morris Water Maze (MWM) tests. Walnut oil was administrated orally at 10 mL/kg body weight/d for 8 consecutive weeks. The results showed that walnut oil treatment ameliorated the behavior of the memory-impaired mice in the MWM test. Additionally, walnut oil obviously inhibited acetylcholinesterase activity (1.26 ± 0.12 U/mg prot) (p = 0.013) and increased choline acetyltransferase activity (129.75 ± 6.76 U/mg tissue wet weight) in the brains of scopolamine-treated mice (p = 0.024), suggesting that walnut oil could prevent cholinergic function damage in mice brains. Furthermore, walnut oil remarkably prevented the decrease in total superoxide dismutase activity (93.30 ± 5.50 U/mg prot) (p = 0.006) and glutathione content (110.45 ± 17.70 mg/g prot) (p = 0.047) and the increase of malondialdehyde content (13.79 ± 0.96 nmol/mg prot) (p = 0.001) in the brain of scopolamine-treated mice, indicating that walnut oil could inhibit oxidative stress in the brain of mice. Furthermore, walnut oil prevented histological changes of neurons in hippocampal CA1 and CA3 regions induced by scopolamine. These findings indicate that walnut oil could prevent memory impairment in mice, which might be a potential way for the prevention of memory dysfunctions.