Neuroprotective effects of flavonoids extracted from licorice on kainate-induced seizure in mice through their antioxidant properties

Abstract

Abstract:A relationship between status epilepticus (SE) and oxidative stress has recently begun to be recognized. To explore whether the flavonoids extracted from licorice (LFs) have any protective effect on kainate (KA)-induced seizure in mice, we treated mice with LFs before and after KA injection. In KA-treated mice, we found that superoxide dismutase (SOD) activity decreased immediately after the onset of seizure at 1 h and then increased at 6 h. It returned to baseline 1 d after seizure and then increased again at 3, 7, and 28 d, while malondialdehyde (MDA) content remained at a high level at 1 h, 6 h, 3 d, 7 d, and 28 d, indicating a more oxidized status related to the presence of more reactive oxygen species (ROS). Treatment with LFs before KA injection reversed the seizure-induced change in SOD activity and MDA content at 1 h, 6 h, 3 d, 7 d, and 28 d. Treatment with LFs after seizure decreased KA-induced SOD activity and MDA content at 7 and 28 d. Also, LF pre-and post-KA treatments decreased seizure-induced neuronal cell death. Subsequently, Morris water maze tests revealed that the escape latency was significantly decreased and the number of target quadrant crossings was markedly increased in the LF-treated groups. Thus, our data indicate that LFs have protective effects on seizure-induced neuronal cell death and cognitive impairment through their anti-oxidative effects.

Status epilepticus: Using antioxidant agents as alternative therapies

“…Although the use of antioxidants as a therapy against epilepsy has been described since 1970s, extensive studies on the use of antioxidants for treatment of SE have been reported since 2000. Different studies have demonstrated the use of antioxidants in SE, for the treatment of SE, indicating that pretreatment with vitamin E, vitamin C, coenzyme Q10, N-acetyl-cysteine, 7-nitroindazole, melatonin and various plant extracts or flavonoids reduces lipid oxidation and restores the activities of SOD, CAT and NOS and the levels of GSH in the rat hippocampus, striatum or cortex (82)(83)(84)(85)(86)(87)(88)(89)(90)(91)(92)(93)(94)(95)(96)(97)(98)(99)(100). The complete information is available upon request.…”

Effect of tualang honey against KA-induced oxidative stress and neurodegeneration in the cortex of rats

“…Kainic acid (KA), a neurotoxicant extracted from red alga, Digenea simplex, is widely used to induce seizures and to explore the mechanism of excitotoxicity and neurodegeneration. Studies on KA-induced animal experimental model have shown series of clinical manifestations and pathological changes upon KA administration on rodents such as seizures [2], behavioral changes of rodents [3, 4], oxidative stress [5, 6] and neuropathological lesions akin to those found in patients with TLE [7]. …”

“…Many studies have tested or reported the protective effect of various types of natural products against KA-induced excitotoxicity models [3, 8–11]. Many of natural products possess antioxidant activity that enables them to protect against KA –induced neuronal degeneration and KA-induced seizures.…”

Review of the use of botanicals for epilepsy in complementary medical systems — Traditional Chinese Medicine

“…Licorice flavonoids, the major bioactive components of licorice root, have demonstrated various antioxidant, antitumor, and antiviral biochemical activities [80][81][82]. One recent study demonstrated that the licorice flavonoid extract has protective effects on seizure-induced neuronal cell death and cognitive impairment through its antioxidative effects [83]. This finding may suggest a potential use in the prevention and treatment of seizure-induced brain injury.…”