Effects of Hypericum scabrum extract on dentate gyrus synaptic plasticity in high fat diet-fed rats

Abstract

High-fat diet (HFD) can induce deficits in neural function, oxidative stress, and decrease hippocampal neurogenesis. Hypericum (H.) scabrum extract (Ext) contains compounds that could treat neurological disorders. This study aimed to examine the neuroprotective impacts of the H. scabrum Ext on hippocampal synaptic plasticity in rats that were fed HFD. Fifty-four male Wistar rats (220 ± 10 g) were randomly arranged in six groups: (1) HFD group; (2) HFD + Ext300 group; (3) HFD + Ext100 group; (4) Control group; (5) Ext 300 mg/kg group; (6) Ext 100 mg/kg group. These protocols were administrated for 3 months. After this stage, a stimulating electrode was implanted in the perforant pathway (PP), and a bipolar recording electrode was embedded into the dentate gyrus (DG). Long-term potentiation (LTP) was provoked by high-frequency stimulation (HFS) of the PP. Field excitatory postsynaptic potentials (EPSP) and population spikes (PS) were recorded at 5, 30, and 60 min after HFS. The HFD group exhibited a large and significant decrease in their PS amplitude and EPSP slope as compared to the control and extract groups. In reverse, H. scabrum administration in the HFD + Ext rats reversed the effect of HFD on the PS amplitude and EPSP slope. The results of the study support that H. scabrum Ext can inhibit diminished synaptic plasticity caused by the HFD. These effects are probably due to the extreme antioxidant impacts of the Ext and its capability to scavenge free radicals.

Usage of encapsulated Hypericum scabrum in Ayran and determination of antioxidant, phenolic and sensory properties

“…HS extract is a powerful source of antioxidant on the account of its composition. Omidi et al (2020) determined that HS contains flavonoids such as quercitrin and quercetin that can scavenge the free radicals. Previous studies revealed that TPC amount of microcapsule is quite high when compared with its extract form.…”

The effects of carvacrol and p‐cymene on Aβ1‐42‐induced long‐term potentiation deficit in male rats

“…LTP data were normalized to the mean value of fEPSP slopes and PS amplitude recorded before LTP induction (Equation 3 ). 43 , 51 , 52 p ‐values less than 0.05 were regarded as significant. …”

Learning and Memory Impairment Induced by Amyloid Beta Peptide and Effects of Thymol on Hippocampal Synaptic Plasticity in Rats Fed a High-Fat Diet That Received Amyloid Beta

“…Oxidative stress is responsible for the pathogenesis of several diseases, including memory deficits caused by oxidative damage in rats and humans. The brain undergoes severe damage under oxidative stress due to the abundance of unsaturated fatty acids, lower antioxidant protection, redox-active metals (Fe, Cu), and high oxygen concentrations [7,23,29].…”

“…However, AD treatment via antioxidants is met with great suspicion, as most of them can hardly cross the BBB. Accordingly, smaller antioxidant molecules or non-toxic carriers can provide favorable modifications for the current complications [25,26,29].…”