Cryptotanshinone Alleviates Oxidative Stress and Reduces the Level of Abnormally Aggregated Protein in Caenorhabditis elegans AD Models.

Alzheimer's disease (AD) is one of the leading causes of dementia. As the first common neurodegenerative disease, there are no effective drugs that can reverse the progression. The present study is to report the anti-AD effect of cryptotanshinone (CTS), a natural product isolated from Salvia castanea. It is found that it can alleviate AD-like features associated with Aß1-42 toxicity in muscle cells as well as neuronal cells of Caenorhabditis elegans (C. elegans). Further studies showed that CTS reduced the level of reactive oxygen species (ROS) in nematodes, up-regulated the expression of sod-3, and enhanced superoxide dismutase activity. Cryptotanshinone reduced the level of Aß monomers and highly toxic oligomers in C. elegans while inhibiting the abnormal aggregation of polyglutamine protein. In addition, CTS upregulated the expression of hsp-16.2 and downregulated the expression of ace-2. These results suggested that CTS could alleviate oxidative stress and reduce the level of abnormally aggregated proteins and has the potential to be developed as an anti-AD drug candidate.

Two new aromatic derivatives from Codonopsis pilosula and their α-glucosidase inhibitory activities.

The ethanol extract of the roots of Codonopsis pilosula was subjected to chromatographic fractionation, which result in the isolation and characterization of two new aromatic derivatives 2,3-dihydroxypropyl 2,4-dihydroxy-3,6-dimethylbenzoate (1) and 2-oxopropyl 3-hydroxy-4-methoxybenzoate (2), along with three known compounds pilosulinene A (3), pollenfuran B (4) and (+)-pinoresinol (5). Their structures were demonstrated by HRESIMS and spectroscopic methods including NMR and IR. It is worth noting that compound 4 was isolated for the first time from the genus Codonopsis. The potential hypoglycemic properties of compounds 2-5 were evaluated by measuring their α-glucosidase inhibitory effects. As a result, compounds 2 and 3 showed weak α-glucosidase inhibitory activities with IC50 values of 154.8 ± 11.0 µM and 24.0 ± 2.2 µM, respectively.[Formula: see text].

Polyoxygenated sesquiterpenoids from Salvia castanea and their potential anti-Alzheime's disease bioactivities.

Salvia castanea (Family Labiatae), a perennial fragrant herb with castaneous flowers, is mainly distributed in areas with an altitude of 2500-3750 m. The roots of this plant were used as a tea drink by local residents to strengthen physical health. The aim of present study was to acquire secondary metabolites of the ethanol extract obtained from the whole plant of S. castanea and to evaluate their potential anti-Alzheimer's disease. Six new sesquiterpene lactones, salcastanins A-F (1-6), together with three known guaiane-type sesquiterpenoids nubiol (7), nubdienolide (8), and nubenolide (9), were separated from the whole plant of S. castanea. The structures of these compounds were determined by HRESIMS and NMR experiments. The absolute configurations of 1-6 were ascertained by electronic circular dichroism (ECD) experiments. The humanized Caenorhabditis elegans AD pathological model was used to evaluate anti-Alzheimer's disease (AD) activities of 1-9. The results showed the compounds 1-3 and 7 significantly delayed AD-like symptoms of worm paralysis phenotype, which could be used as novel anti-AD candidates.

Isolation, Characterization, and Possible Anti-Alzheimer's Disease Activities of Bisabolane-Type Sesquiterpenoid Derivatives and Phenolics from the Rhizomes of Curcuma longa.

One new bisabolane-type sesquiterpenoid, together with four known bisabolane-type sesquiterpenoid derivatives and seven phenolics, was isolated from the rhizomes of Curcuma longa. Their structures were elucidated by extensive spectroscopic (IR, HR-ESI-MS, and NMR) data analysis. The possible anti-Alzheimer's disease (AD) activities of the isolated compounds were also evaluated using Caenorhabditis elegans AD pathological model, and 1ß-hydroxybisabola-2,10-dien-4-one had the highest possible anti-AD activity.

Eupulcherol A, a triterpenoid with a new carbon skeleton from Euphorbia pulcherrima, and its anti-Alzheimer's disease bioactivity.

Eupulcherol A (1), a novel triterpenoid with an unprecedented carbon skeleton, was isolated from Euphorbia pulcherrima. Its structure was determined by comprehensive analysis of spectroscopic data, including HRESIMS and 1D and 2D NMR, and the absolute configuration was defined by single crystal X-ray diffraction analysis. Biological studies showed that compound 1 possessed anti-Alzheimer's disease (AD) bioactivity, which could delay paralysis of transgenic AD Caenorhabditis elegans. A plausible biogenetic pathway for eupulcherol A (1) was also proposed.

Narjatamanins A and B, a pair of novel epimers possessing a 2,3-seco-iridoid skeleton with an unusual 1,10-oxygen bridge from Nardostachys jatamansi and evaluation of their effects on worm paralysis in AD C. elegans.

Narjatamanins A (1) and B (2), a pair of epimers possessing a novel 2,3-seco-iridoid skeleton with an unusual 1,10-oxygen bridge, were isolated from the whole plants of Nardostachys jatamansi. Their structures were elucidated by a combination of various spectroscopic methods, including HRESIMS, IR and 1D and 2D NMR techniques. The absolute configurations of 1 and 2 were established by electronic circular dichroism (ECD) calculations. The pharmacological activities of 1 and 2 to alleviate AD-like symptoms were also evaluated using the Caenorhabditis elegans Alzheimer's disease (AD) pathological model, and narjatamanins A (1) and B (2) showed statistically significant delay in the worm paralysis phenotype of AD-like symptoms.