Natural sesquiterpen lactones as acetylcholinesterase inhibitors

Abstract

Background and the purpose of the study: The amount of elder people who suffer from Alzheimer disease is continuously increasing every year. Cholinesterase inhibitors have shown to be effective in alleviating the symptoms of the disease, thus opening a field of research for these treatments. Herbal products, owning a reputation as effective agents in many biological studies are now drawing attention for inhibiting acetylcholinesterase, in other words, Alzheimer disease. In the present study, the ability of three sesquiterpene lactones from Inula oculus-christi and I. aucheriana to inhibit AChE has been evaluated through Ellman assay. Materials and Methods: Gaillardin and pulchellin C were obtained from I. oculus-christi and britannin from I. aucheriana by chromatographic methods. They were dissolved in methanol in concentration of 3 mg/mL and the AChEI activity of the compounds was determined by Ellman method using Acethylthiocholine iodide as the substrate and 5, 5'-dithiobis-2-nitrobenzoic acid as the reagent, in 96-well plates at 405 nm. Results: AChEI activity of the examined compounds was obtained as 67.0, 25.2 and 10.9% in concentration of 300 μg/L for gaillardin, britannin and pulchellin C, respectively. Conclusion: Among the three sesquiterpene lactones, gaillardin with 67% inhibition of AChE could be considered a good candidate for future Alzheimer studies.

Non-Alkaloid Cholinesterase Inhibitory Compounds from Natural Sources

“…Several terpenoids from natural sources have been reported as cholinesterase inhibi-tors [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. The compounds 1 – 11 , as shown in Supplementary Material ( Table S1 ), are of the Abietane-type diterpene skeletons isolated from Salvia austriaca , Salvia glutinosa , Caryopteris mongolica, and Perovskia atriplicifolia [ 14 , 15 , 16 ].…”

Caffeoylquinic Acids, Cytotoxic, Antioxidant, Acetylcholinesterase and Tyrosinase Enzyme Inhibitory Activities of Six Inula Species from Bulgaria

“…Inulavosin, a melanogenesis inhibitor isolated from I. nervosa , reduced the melanin content without affecting either the enzymatic activities or the transcription of tyrosinase or Tyrp1 in B16 melanoma cells . Gaillardin, a sesquiterpene lactone isolated from I. oculus‐christi chloroform extract showed reasonable inhibition of acetylcholinesterase enzyme (67 %) at a concentration of 300 μg/mL …”

Alantolactone and Isoalantolactone Prevent Amyloid β25–35‐induced Toxicity in Mouse Cortical Neurons and Scopolamine‐induced Cognitive Impairment in Mice

“…Thus, the protective effects of AL and IAL from scopolamine‐induced cognitive impairment could depend on their ability to stimulate Nrf2 signaling and thereby induce antioxidant enzymes, although some sesquiterpenoids were found to inhibit AChE effectively (Hajimehdipoor et al, ). Furthermore, Nrf2 −/− mice showed consistently lower cognitive capabilities than wild‐type mice, confirming that antioxidant enzymes play an important role in cognitive function and memory.…”