KR20060125756A - Utilization of vinpocetine to avoid complications in particular those associated to hearing which occur with epilepsy, and treatment thereof - Google Patents

Abstract

The present invention relates to the utilization of vinpocetine and the derivatives thereof which can be develop while keeping the same effects for the treatment of epilepsy and its complications. The results obtained show that vinpocetine inhibits all alterations of waves of RATC which accompany the cortical epileptic activity during the ictal and post-ictal period in two experimental models of epilepsy in vivo, that vinpocetine also inhibits the marked loss of hearing and the characteristics changes of EEG which are induced by two convulsive agents which differ in their action mechanism. These findings indicate that the capacity of vinpocetine as antiepileptic drug has no adverse secondary effects.

Description

Utilization of vinpocetin for the prevention and treatment of complications, especially hearing-related complications, with epilepsy

The present invention relates to the use of vinpocetine and derivatives thereof which maintain the same effect on the treatment of epilepsy and its complications, in particular complications related to the auditory pathway.

One of the major problems of epilepsy is not only caused by the disease (Prevey et al., 1998 Epilepsy Res. 30: 1; Jokeit and Ebner 1999 J. Neurol . Neurosurg. Psychiatry 67: 44; Theodore et al., 1999 Neurology 52: 132 Meador 2001 Epilepsy Behav. 2: 307) caused by treatment with commonly used antiepileptic drugs (Gates 2000 Epilepsy Behav . 1: 153; Kwan and Brodie 2001 Lancet 357: 216; Brunbech and Sabers 2002 Drugs 62: 593; Schmidt 2002 Epilepsy Res. 50: 21) Harmful cognitive and behavioral consequences.

The association of auditory brainstem nuclei in the pathophysiology of systemic epilepsy is indicated by alterations in the latency and / or size of the late wave of the auditory brainstem response (ABR) observed in patients with systemic epilepsy (Rodin et al ., 1982 Clin . Electroencephalogr 13:. 154; Mervaala such as 1986 Epilepsia 27: 542; Phillips, such as 1990 Clin Electroencephalogr 21:.. 135 ; Soliman such as 1993 Ear Hear 14: 235; Kohsaka, such as 1999 Brain Res 837:. 277; Kohsaka , such as 2001 Brain Res . 903: 53). Acute epilepsy induced by two seizure agents in non-drug animals is accompanied by abnormal ABR waves and significant hearing loss (Nekrassov and Sitges 2003 Epilepsy Res. 53: 245).

ABR is a far-field induced potential consisting of several waves that occur within 10 ms after auditory stimulation. Since the late wave changes in ABR indicate alterations in certain auditory brainstem nuclei (Hughes, JR, Fino, JJ, 1985 J. Clin . Neurophysiol . 2: 355), ABR is a disease of retro-cochlear lesions. It is commonly used for clinical diagnosis. In addition, the ABR threshold is used for the clinical diagnosis of hearing sensitivity, as progressively higher intensity stimuli (in dB) are required for the induction of ABR as hearing sensitivity decreases. Thus, raising the ABR threshold is an objective decision for hearing loss.

In addition, antiepileptic drugs, including carbamazepine, valproate, phenytoin, phenobarbital, clonazepam and vigabatrin, are not only hearing loss, It also causes abnormalities in ABR waves (Mervaala et al . 1987 Electroencephalogr . Clin . Neurophysiol . 68: 475; Armon et al . 1990 Neurology 40: 1896; Hirose et al . 1990 Electroencephalogr . Clin . Neurophysiol. 75: 543; Yuksel et al . 1995 Childs Nerv . Syst. 11: 474; De la Cruz and Bance 1999 Arch Otolaryngol Head Neck Surg . 125: 225; Zgorzalewicz and Galas-Zgorzalewicz 2000 Clin . Neurophysiol . 111: 2150).

Vinpocetin (ethyl apovincarmine-22-oate), discovered in the late 1960s, has been successfully used for the treatment of cerebrovascular-derived central nervous system disorders for decades. In animal models of hypoxia and ischemia, vinpocetin has a beneficial effect on neuronal damage (King 1987 Arch. Int . Pharmacodyn . Ther . 286: 299; Araki et al. 1990 Res .. Exp .. Med. 190: 19).

More recently, vinpocetin has also been used to improve memory based on previous studies in animals and humans (Subhan and Hindmarch 1985 Eur . J. Clin . Pharmacol. 28: 567; Bhatti and Hindmarch 1987 Int . Clin . Psychopharmacol 2: 325; DeNoble 1987 Pharmacol Biochem Behav 26:.... 183).

Vinpocetin is a Na ⁺ channel blocker (Erdo et al. 1996 Europ . J. Pharmacol . 314: 69). It has been found by the present inventors that vinpocetin selectively inhibits neurotransmitter release induced by an increase in anterior synaptic Na ⁺ channel permeability at the nerve endings isolated in the brain (Sitges and Nekrassov, 1999 Neurochem . Res. . 24: 1587; Trejo, including 2001 Brain Res 909:. 59) . Furthermore, in vivo in guinea pigs, vinpocetin has been shown to affect ABR wave alterations, hearing loss and amikacin (Nekrassov and Sitges 2000 Brain Res. 868: 222) and other aminoglycoside antibiotics (unpublished results). It has been found by the inventors that long term inhibition of lethality induced by

There is an open medical need for the treatment of epilepsy. Drug administration with antiepileptic drugs in both "old and new generations" has a positive effect on seizure control (at least about 70% of patients with epilepsy) but impairs cognitive function (Vermeulen and Aldenkamp 1995 Epilepsy Res. 22: 65 Gates 2000 Epilepsy Behav . 1: 153; Brunbech and Sabers 2002 Drugs 62: 593; Schmidt 2002 Epilepsy Res. 50: 21), which may exacerbate the cognitive decline caused by the disease (Prevey et al. 1998 Epilepsy Res. 30: 1; Jokeit and Ebner 1999 J. Neurol . Neurosurg . Psychiatry 67: 44; Theodore et al. 1999 Neurology 52: 132; Meador 2001 Epilepsy Behav . 2: 307). In addition, antiepileptic drugs cause alteration of ABR waves (Mervaala et al . 1987 Electroencephalogr . Clin . Neurophysiol. 68: 475; Armon et al . 1990 Neurology 40: 1896; Hirose et al . 1990 Electroencephalogr. Clin . Neurophysiol . 75: 543; Yuksel et al . 1995 Childs Nerv . Syst. 11: 474; De la Cruz and Bance 1999 Arch Otolaryngol Head Neck Surg . 125: 225; Zgorzalewicz and Galas-Zgorzalewicz 2000 Clin . Neurophysiol . 111: 2150), which can cause hearing loss (Nekrassov and Sitges 2003 Epilepsy Res. 53: 245); It does not provide a recognizable effect on the prevention of disease after the first seizure (Hernandez 1997 Trends Pharmacol . Sci . 18: 59; Temkin et al. 2001 Drugs 61: 1045; Schmidt 2002 Epilepsy Res. 50: 21).

Common antiepileptic drugs cause some secondary adverse effects, which in many cases cause the patient to discontinue treatment due to significant changes that limit the patient's daily life.

The present invention refers to the use of vinpocetin and its derivatives, which maintain the same effect on the preparation of the drug of choice in the treatment of epilepsy. The present invention describes the beneficial action of vinpocetin for preventing interstitial cortical activity during seizures and post-seizure periods and for preventing the most important disorders aggravated by antiepileptic drugs caused and commonly used by the disease.

FIG. 1 shows in (a) an animal prior to injection of pentylenetetrazole (PTZ) and an animal pre-injected with vehicle before 4 hours of PTZ injection and (b) and an animal pre-injected with vinpocetin 4 hours before PTZ injection. 50 minutes after PTZ injection, ABR records taken from representative animals are shown. The animals underwent pure tone unilateral stimulation of high frequency (8 kHz) and high intensity (100 dB) where indicated by the arrows.

2 shows that vinpocetin inhibits the peak transient increase of P2, P3 and P4 waves of ABR induced by PTZ. A brief period of waves induced by 100 dB stimulation at sound frequencies of 8 kHz (left graph) and 4 kHz (right graph) was pre-injected with control animals (black circles) pre-injected with vehicle and 2 mg / kg vinpocetin Animals were measured prior to PTZ injection and at 10, 20, 30 and 50 minutes post injection. Results are mean ± SEM values in 8 independent animals.

3 shows that vinpocetin inhibits changes in EEG (EEG) induced by PTZ during the seizure period. EEG records shown were taken from representative animals prior to PTZ injection (top dashed line), either from animals pre-injected vehicle 4 hours before PTZ injection (midline dashed line) or from animals pre-injected with Vinpocetin 4 hours before PTZ injection. (Bottom dashed line) Taken about 2 minutes after PTZ injection.

4 shows that vinpocetin inhibits changes in EEG induced by PTZ during the post-seizure period. EEG recordings were taken prior to PTZ injection (top dashed line) and 10, 20, 30 and 50 minutes after PTZ injection in representative animals pre-injected with vehicle. EEG recordings were taken prior to PTZ injection (top dashed line) and 10, 20, 30 and 50 minutes after PTZ injection in representative animals pre-injected with vinpocetin.

5 shows that vinpocetin inhibits the size change of late ABR waves induced by another convulsive agent, 4-aminopyridine (4-AP). ABR was induced by stimulation of 100 dB at 8 kHz. The gradual increase in P3 wave size of ABR observed after injection of 4-AP in control animals (a) was not seen in animals (b) pre-injected with vinpocetin, and observed after injection of 4-AP in control animals (c). A marked reduction in the P4 wave size of ABR has been shown to be significantly reduced in vinpocetin dosed animals (d).

6 shows that vinpocetin inhibits changes in EEG induced by 4-AP during the seizure period. EEG recordings shown in (a) were taken from representative animals before and 4-20 injections of vehicle pre-injected animals. EEG recordings shown in (b) were taken from representative animals before and 4-20 injections of 4-AP to animals previously injected with 2 mg / kg vinpocetin.

Figure 7 shows that vinpocetin inhibits the change in EEG induced by 4-AP during the post-seizure period. EEG recordings shown in (a) were taken at representative animals pre-injected with vehicle, prior to injection of 4-AP (top dashed line) and at 30, 60 and 80 minutes after injection. EEG recordings shown in (b) were taken before representative injection of 4-AP (top dashed line) and at 30, 60 and 80 minutes post injection in representative animals pre-injected with vinpocetin.

In prior studies, we found that alterations in the lateral and central nuclei of the superior olivary complex, which are reflected in the parameters (size and temporal) of the late wave of ABR, are associated with hearing loss caused by epilepsy. (Nekrassov and Sitges 2003 Epilepsy Res. 53: 245).

The present invention demonstrates that vinpocetin inhibits the size and transient alteration of late ABR waves, as well as the characteristic interstitial cortical activity and hearing loss observed in two models of experimental animal epilepsy in vivo.

Epilepsy can be induced in experimental animals in vivo by reducing cerebral inhibitory delivery or by increasing cerebral excitatory delivery. Epilepsy induction can be achieved by injecting GABA antagonists, PTZ or glutamate emitters, 4-aminopyridine (4-AP), respectively. The present results in guinea pigs show that when intraperitoneally administered iposetin at a dose of 2 mg / kg 4 hours prior to PTZ injection or 1 hour prior to 4-AP injection, none of these convulsants were associated with the size of the late ABR wave. Impaired induction, induced hearing loss, or induced interstitial cortical activity.

In guinea pigs, the P3 and P4 waves of ABR show the activity of the olive nucleus on the central and lateral sides, respectively (Wada and Starr 1983 Electroencephalogr . Clin . Neurophysiol . 56: 326; 56: 340; 56: 352). Among the nuclei of upper olives, the P4 generator determines the source locality (Tollin 2003 Neuroscientist 9: 127). Changes in the latter wave of the ABR indicate a retrospective change. Vinpocetin cancels out all aftermirror abnormalities induced by PTZ or 4-AP (as evidenced by changes in P3 and / or P4 parameters), thereby preventing the hearing loss induced by both convulsants.

Common antiepileptic drugs induce parameter changes in ABR waves and hearing deficits that can exacerbate abnormalities and hearing loss induced by the disease. Drug administration of antiepileptic drugs has a positive effect on seizure control, but also causes secondary adverse effects, among which cognitive decline and hearing loss are particularly important. Vinpocetin is well-tolerated and is not contraindicated in humans at high doses as high as 60 mg / day (Hindmarch et al . 1991 Int . Clin . Psychopharmacol . 6: 31). The results indicate that a reasonable dose (2 mg / kg) of vinphocetin completely cancels the seizure and post seizure cortical activity induced by PTZ and 4-AP, as well as hearing loss induced by both convulsants. The contribution of cognitive decline to hearing loss by epilepsy and classic antiepileptic drugs is prevented by vinpocetin, which indicates the use of vinpocetin as an antiepileptic agent for classical antiepileptic therapy.

Another problem with commonly used antiepileptic drugs is that they do not produce a recognizable impact on epileptic origin or disease course. In previous studies, we found that vinpocetin exhibits long-term (greater than half a year) protection against changes in ABR waves, hearing loss, and lethality induced by treatment with high amikacin doses. (Nekrassov and Sitges 2000 Brain Res. 868: 222), suggesting that vinpocetin may also represent an important preventive action in the treatment of epilepsy.

In summary, the present findings have shown that vinpocetin prevents interstitial cortical activity during seizures and post-seizure periods, as well as alteration of ABR waves that cause hearing loss and contribute to cognitive effects caused by epilepsy and commonly used antiepileptic drugs Point out that Along with the long-term protective action of vinosetin, the findings indicate that vinosecetin is a better alternative to the treatment and prevention of epilepsy.

Experiments were performed with colored adult male guinea peaks with an initial body weight of 349 ± 38 g. ABR records were used to assess the hearing status of each animal, and EEG records were used to assess changes in cortical excitability. ABR and EEG records were obtained according to previously reported methods (Nekrassov and Sitges, 2003). The Institutional Animal Use and Care Committee approved all experimental procedures.

Three types of recordings were performed in anesthetized animals: ABR recordings derived by high intensity stimulation (100 dB), ABR recordings for determination of auditory thresholds, and EEG recordings.

Determination of ABR wave parameters. The temporal and magnitude of each wave component of the ABR derived by the 100 dB stimulus using pure sound frequencies of 4 and 8 kHz was measured in all ABR records obtained under different experimental conditions at specific times. The duration (in ms) of each ABR wave is the time interval between the onset of the auditory stimulus and the positive peak of the wave. Stimulus initiation is indicated by a vertical arrow at the bottom of the recorder in FIG. The peak size (in μV) of each wave of ABR is the difference between the positive peak of the wave and the reference baseline (the line between the stimulus and the first ABR wave appearance in FIG. 1).

Determination of the ABR threshold. ABR records derived by progressively lower intensity stimuli (in dB) were used to determine hearing thresholds. The threshold is defined as the lowest stimulus intensity (in dB) that the P3 wave of ABR can still be recorded in three consecutive tests.

Student's t-test was used to assess the difference between the results obtained at specific times before and after injection of the convulsant. The criterion for statistical significance on all scales was P ≦ 0.05. All data are expressed as mean ± standard error of the mean. In the figures and tables, the symbol * is used to indicate statistical significance.

Example 1. Experimental design used to test the effects of vinpocetin on changes in ABR and EEG recordings induced by epilepsy resulting from reduced cerebral inhibitory delivery.

Eight male guinea pigs were introduced into the study. PTZ was dissolved in saline, vinpocetin in acidified saline (using HCl) and adjusted to pH 4 (using NaOH). Four hours after injection of vehicle (acidified saline used to dissolve vinpocetin) into guinea pigs, the animals were anesthetized and the first set of ABR and EEG records obtained before injection (intraperitoneal) of the spasm agent PTZ. The animals were injected with PTZ (100 mg / kg) and about 2 minutes after the PTZ injection (seizure period), EEG recordings were taken. Then another series of ABR and EEG records were taken at specific times in the post-seizure period. Two weeks later, a series of identical records were obtained with vinpocetin (2 mg / kg) instead of vehicle injected 4 hours prior to PTZ injection.

The following table shows that vinpocetin inhibits the reduction of P4 wave peak size induced by PTZ. In control animals (animals pre-injected with vehicle), the magnitude of the P4 wave of ABR induced by 100 dB stimulation at two sound frequencies (8 and 4 kHz) gradually decreased by PTZ (left column), In animals pre-injected with vinpocetin, no decrease in P4 size that is induced by PTZ is observed (right column). The values shown in the table are the mean ± standard error of the P4 wave size (in μV) obtained from 8 animals at the indicated time before and after injection of the convulsant (PTZ).

8 kHz PTZ 8 kHz Vinpocetin & PTZ Before injection 2.88 ± 0.1 2.69 ± 0.1 10 minutes 2.07 ± 0.4 * 2.56 ± 0.1 20 minutes 1.99 ± 0.3 * 2.71 ± 0.2 30 minutes 1.92 ± 0.3 * 2.55 ± 0.2 50 minutes 1.51 ± 0.5 * 2.56 ± 0.1

4 kHz PTZ 4 kHz Vinpocetin & PTZ Before injection 3.14 ± 0.1 2.82 ± 0.3 10 minutes 1.70 ± 0.5 * 2.55 ± 0.3 20 minutes 2.12 ± 0.4 * 2.52 ± 0.2 30 minutes 1.84 ± 0.4 * 2.55 ± 0.2 50 minutes 2.11 ± 0.3 * 2.52 ± 0.2

In addition, vinpocetin inhibits the transient increase of ABR waves P2, P3 and P4 induced by 100 dB stimulation at 4 and 8 kHz sound frequencies after the injection of PTZ (FIG. 2).

The following table shows that vinpocetin inhibits hearing loss induced by the convulsive PTZ. A significant increase in auditory threshold (left column) at 4 and 8 kHz sound frequencies induced by PTZ does not occur in animals pre-injected with vinpocetin prior to PTZ administration (right column). The values shown in the table are the mean ± standard error of the threshold (in dB) obtained from 8 animals.

PTZ Vinpocetin & PTZ 8 kHz Before injection 7.0 ± 1.2 6.0 ± 1.0 30 minutes 17 ± 2.0 * 6.0 ± 1.0 50 minutes 21 ± 2.4 * 6.0 ± 1.0 4 kHz Before injection 21 ± 1.0 20 ± 1.6 30 minutes 28 ± 2.0 * 18 ± 1.2 50 minutes 29 ± 1.0 * 18 ± 1.2

Vinpocetin inhibits all changes induced by PTZ on EEG. All anesthetized animals injected with PTZ developed generalized seizures. Onset of seizure activity characterized by repetitive high magnitude spiked sharp wave activity in the EEG dashed line suddenly occurs within the first two minutes after PTZ injection. After such rapid changes in cortical activity induced by PTZ in anesthetized animals during convulsions, the usual cortical activity pattern is characterized by high magnitude periodic spike-like waves. The duration of such a typical cortical activity pattern without convulsions is referred to as post seizure period.

Vinpocetin completely inhibits cortical activity changes induced by PTZ during seizures and post-seizure periods. The top dashed lines in FIGS. 3 and 4 show characteristic EEG recordings under control conditions (ie, prior to PTZ scan). In the animals pre-injected with vehicle, the abrupt change induced about 2 minutes after the PTZ injection on the EEG (seizure period) is lost when PTZ was injected into the pre-injected vinpocetin (FIG. 3). In the same manner as above, changes induced by PTZ after 10, 20, 30 and 50 minutes of injection (FIG. 4A) are lost in animals previously injected with vinpocetin (FIG. 4B).

Example 2 Experimental Design Used to Test the Effect of Vinpocetin on Changes in ABR and EEG Records Induced by Increased Cerebral Excitatory Delivery.

Five guinea pigs were introduced into this study. One hour after injecting the guinea pig with the vehicle (acidified saline used to dissolve vinpocetin), the animals were anesthetized and the first set of ABR and EEG records were taken before the cramping 4-AP injection (intraperitoneal). Animals were injected with 4-AP (2 mg / kg) and EEG records were taken approximately 20 minutes after the 4-AP injection (seizure period). Then another series of ABR and EEG records were taken at specific times in the post-seizure period. Two weeks later, the same series of recordings were repeated, but instead of vehicle, vinpocetin (2 mg / kg) was injected into the animal 1 hour before 4-AP injection.

Vinpocetin also inhibits changes in P3 and P4 wave size induced by 4-AP. For example, a gradual increase in P3 wave size of ABR caused by 4-AP in control animals (FIG. 5A) was not found in animals treated with vinpocetin (FIG. 5B), and caused by 4-AP in control animals. The decrease in P4 size is markedly reduced in animals treated with vinpocetin (FIG. 5D).

The following table shows the increase in P4 wave transients (left column) of ABR induced by 100 dB stimulation at 4 and 8 kHz sound frequencies, observed at the time indicated after 4-AP injection in control animals. In case of pre-treatment with animals, 4-AP injection is lost (right column).

8 kHz 4-AP 8 kHz Vinpocetin & 4-AP Before injection 3.48 ± 0.06 3.48 ± 0.04 30 minutes 3.51 ± 0.13 3.55 ± 0.07 60 minutes 3.80 ± 0.10 * 3.45 ± 0.08 80 minutes 3.80 ± 0.10 * 3.36 ± 0.05 100 minutes 3.83 ± 0.12 * 3.35 ± 0.07

4 kHz 4-AP 4 kHz Vinpocetin & 4-AP Before injection 3.50 ± 0.02 3.45 ± 0.06 30 minutes 3.78 ± 0.09 * 3.37 ± 0.06 60 minutes 3.78 ± 0.09 * 3.54 ± 0.11 80 minutes 3.78 ± 0.09 * 3.56 ± 0.04 100 minutes 3.75 ± 0.10 * 3.43 ± 0.09

Vinpocetin inhibits hearing loss induced by 4-AP. The following table shows that the increase in auditory threshold induced by 4-AP (left column) at 8 and 4 kHz sound frequencies in control animals is lost in animals treated with vinpocetin (right column).

4-AP Vinpocetin & 4-AP 8 kHz Before injection 3.8 ± 1.3 2.5 ± 1.4 30 minutes 10.0 ± 2.0 * -1.3 ± 2.4 60 minutes 23.8 ± 6.3 * 0.0 ± 3.5 4 kHz Before injection 13.8 ± 1.3 13.8 ± 1.3 30 minutes 20 ± 2.0 * 11.3 ± 1.3 60 mins 30 ± 3.5 * 11.3 ± 1.3

Vinpocetin inhibits all the changes induced by 4-AP on EEG. All anesthetized animals injected with 4-AP developed generalized seizures characterized by repetitive high-sized spiked sharp wave activity at the EEG line appearing about 20 minutes after 4-AP injection. As described above, the change in cortical activity induced by 4-AP during the seizure period is followed by a post-seizure period characterized by a higher size, isolated spiked form that appears in the EEG about 1 hour after injection of 4-AP. Vinpocetin completely prevents seizures and changes in cortical activity induced by 4-AP during the post-seizure period. The top dashed line in FIG. 6 shows the characteristic EEG records taken prior to 4-AP injection in animals pre-injected with vehicle (a) and animals pre-injected with vinpocetin. The change induced by 4-AP during the seizure period is shown in the second dashed line in FIG. 6A. In animals treated with vinpocetin, 4-AP could not induce seizure activity (second dashed line in FIG. 6B). FIG. 7A shows post-seizure activity induced by 4-AP, which is lost when convulsive agent (4-AP) is injected into an animal previously treated with vinpocetin (FIG. 7B).

Claims (6)

Use of vinpocetin and its derivatives for the manufacture of a medicament useful for the treatment and prevention of neurological diseases, in particular epilepsy, and which can antagonize the altered auditory brainstem response (ABR) waves and the hearing loss. 2. Use of vinpocetin and derivatives thereof as an antiepileptic agent according to claim 1, which inhibits interstitial cortical activity during the seizure and post-seizure period. Use of vinpocetin and its derivatives for the treatment of retro-cochlear-derived alterations according to claim 1, characterized by inhibiting different ABR wave sizes and momentary alterations. The vesicle for treating hearing loss according to claim 1, characterized by inhibiting the increase in auditory threshold induced by various chemicals such as pentylenetetrazole, 4-aminopyridine and some aminoglycoside antibiotics. Use of cetin and its derivatives. The use of vinpocetin and its derivatives in the prevention of neurological diseases according to claim 1, characterized by long-term protection against ABR wave alterations induced by some aminoglycoside antibiotics. Use according to any of the preceding claims, characterized in that the medicament can be administered orally or parenterally in a pharmaceutically acceptable vehicle.

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