Ocimum sanctum extract preserves neuronal echotexture and controls seizure in lithium-pilocarpine induced status epilepticus rats

Abstract

Objective: To investigate the effect of Ocimum sanctum hydroalcoholic extract (OSHE) on seizure control and neuronal injury in rats with lithium-pilocarpine-induced status epilepticus (SE). Methods: SE was induced by administering lithium chloride followed by pilocarpine 24 h later. OSHE was administered either alone or in combination with valproate (VPA) 3 days before SE induction until 14 days post-SE induction. Seizure parameters were recorded on day 1 (0-3 h), day 1-3 and day 4-14 post-SE. On day 14 post-SE, neurobehavioural tests (elevated plus maze and passive avoidance) were done followed by total antioxidant capacity, neuron-specific enolase, immunohistochemistry, and electron microscopic assessment in the hippocampus and cortex tissue. Results: OSHE+VPA provided more significant seizure protection (75%) than VPA (62.5%), OSHE (62.5%), or SE control (12.5%) (overall P=0.003). The latency to stage-3/4 seizures was increased and the number of stage-3/4 seizures was reduced in all treatment groups compared to the SE control group (P=0.002 and <0.001, respectively). The OSHE+VPA group also had better memory retention than other treatment groups (P<0.001) in the passive avoidance test. Total antioxidant capacity level was significantly higher and neuron-specific enolase was lower in the OSHE and OSHE+VPA groups compared to the SE control group. Electron microscopic study showed significant myelin sheath damage (67.5%, P<0.05) and axonal degeneration (51.8%, P<0.001) in the hippocampus of the SE control group, which were alleviated by OSHE or OSHE+VPA treatment. In immunohistochemical analysis, the OSHE, OSHE+VPA, and VPA groups had a significantly higher number of viable neurons and less neuronal loss compared to the SE control in the hippocampus (P<0.001). Conclusions: OSHE either alone or in combination with VPA shows better seizure control by preservation of neuronal echotexture and reducing oxidative stress in the hippocampus.

Keywords

Status epilepticus / Ocimum sanctum / Seizure protection / Neuronal injury / Electron microscopy

Conflict of interest statement

The authors declare that they have no conflict of interest.

Funding

The authors received no extramural funding for the study.

Data availability statement

The data supporting the findings of this study are available from the corresponding authors upon request.

Authors’ contributions

SCS designed the study and approved final version to be published. SCS, SSP, DS, and SS conducted the study, performed the analytic calculations and drafted the article. SCS, MT and SSP contributed to critical revision of the article. TCN facilitated transmission electron microscopy assessment and image interpretation. AN facilitated the immunohistochemistry assessment and image interpretation.

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The Publisher of the Journal remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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