The effects of carvacrol and p‐cymene on Aβ_1‐42‐induced long‐term potentiation deficit in male rats

Abstract

AimsAlzheimer's disease (AD) is the most common type of dementia in which oxidative stress plays an important role. In this disease, learning and memory and the cellular mechanism associated with it, long‐term potentiation (LTP), are impaired. Considering the beneficial effects of carvacrol (CAR) and p‐cymene against AD, their effect was assessed on in vivo hippocampal LTP in the perforant pathway (PP)‐dentate gyrus (DG) pathway in an Aβ1‐42‐induced rat model of AD.MethodsMale Wistar rats were randomly assigned to five groups: sham: intracerebroventricular (ICV) injection of phosphate‐buffered saline, Aβ: ICV Aβ1‐42 injections, Aβ + CAR (50 mg/kg), Aβ + p‐cymene (50 mg/kg), and Aβ + CAR + p‐cymene. Administration of CAR and p‐cymene was done by gavage daily 4 weeks before and 4 weeks after the Aβ injection. The population spike (PS) amplitude and field excitatory postsynaptic potentials (fEPSP) slope were determined in DG against the applied stimulation to the PP.ResultsAβ‐treated rats exhibited impaired LTP induction in the PP‐DG synapses, resulting in significant reduction in both fEPSP slope and PS amplitude compared to the sham animals. Aβ‐treated rats consumed either CAR or p‐cymene separately (but not their combination), and showed an enhancement in fEPSP slope and PS amplitude of the DG granular cells.ConclusionsThese data indicate that CAR or p‐cymene can ameliorate Aβ‐associated changes in synaptic plasticity. Surprisingly, the combination of CAR and p‐cymene did not yield the same effect, suggesting a potential interaction between the two substances.

A Comparison between Bulgarian Tanacetum parthenium Essential Oil from Two Different Locations

“…The anti-oxidant and anti-inflammatory potential could attribute to the gastroprotective effect of the substance revealed in an ethanol-induced gastric ulcer in rats [169]. Moreover, p-cymene can prevent beta-amyloid-caused synaptic plasticity impairment in a rat model of Alzheimer's disease [170] and is reported to possess vasorelaxant [171,172] and anti-tumor effects [161], the latter being mainly manifested when p-cymene is associated with metals in complexes such as ruthenium [173] and osmium [174]. As a natural antimicrobial component, p-cymene in low concentrations could increase the shelf life of un-pasteurised fruit juices [175].…”

Essential Oil Molecules Can Break the Loop of Oxidative Stress in Neurodegenerative Diseases

“…In Wistar rats, orally administered carvacrol was able to counteract the effects of the intracerebroventricular (ICV) injection of amyloid Aβ1-42. Aβ-treated rats exhibited impaired long-term potentiation (LTP) induction in the dentate gyrus, but carvacrol ameliorated Aβ-associated changes in synaptic plasticity [66]. Carvacrol's potential in managing and treating AD and PD has been recently clearly reviewed by Javed and coauthors [67].…”