[Neurometabolic therapy of mild cognitive impairment in patients with chronic cerebral ischemia]

OBJECTIVE

To evaluate the effect of a sequential therapy regimen with Mexidol (500 mg injections intravenously for 14 days) and Mexidol FORTE 250 (250 mg tablets 3 times a day for 60 days) on higher cortical functions in patients with moderate cognitive disorders in chronic cerebral ischemia.

MATERIAL AND METHODS

A comparative, prospective study included 63 patients with chronic cerebral ischemia with moderate cognitive impairment. All patients received basic therapy aimed at reducing risk factors (antihypertensive, antithrombotic drugs as indicated). Patients of the main group (30 people: 12 men, 18 women) received Mexidol intravenously 500 mg in 100 ml of 0.9% NaCl solution once a day for 14 days, then Mexidol FORTE 250 (film-coated tablets) 250 mg 3 times a day for the next 60 days. The comparison group consisted of 33 patients (14 men, 19 women) who received only basic therapy. The groups were comparable in terms of age, sex characteristics and severity of cognitive deficit. We examined cognitive status (MoCA scale, Frontal Dysfunction Battery, 10 Word Memorization tests), severity of asthenia (MFI-20 scale), anxiety and depression (HADS scale), patient's subjective assessment of the dynamics of the condition (CGI-improvement scale) in 1st, 14th and 74th±5 days of observation. On days 1 and 74±5 of observation, patients were examined using transcranial magnetic stimulation to study the neuronal activity of the cerebral cortex.

RESULTS

In the main group, at the time of completion of taking Mexidol and Mexidol FORTE 250, a pronounced cognitive regression was noted (MoCA scale +3 points, difference with the comparison group 1 point (p<0.0001); Frontal Dysfunction Battery test +4 points, difference with comparison group 2 points (p<0.001); memory test «10 words» +2 points, difference with the comparison group 1 point (p<0.05), emotional (HADS anxiety scale -8 points, difference with the comparison group 3 points (p<0.001), depression -3.5 points, difference with the comparison group 1.5 points (p<0.01), asthenic disorders (MFI-20 scale -30 points, difference with the comparison group 15.5 points (p<0.01), improvement in the well-being of patients (CGI-improvement scale -2 points, difference with the comparison group 1 point (p<0.0001). According to the transcranial magnetic stimulation performed, a statistically significant decrease in the central motor conduction time at the level of 1 and 2 motor neurons of the pyramidal tract bilaterally from the start to the end of therapy with Mexidol and Mexidol FORTE 250 was determined (p<0.01). An inverse correlation was found between the time of central motor conduction and the results of the Frontal Dysfunction Battery test at the same time points with left-sided localization of 1 motor neuron (p<0.01). The results of a study of the use of sequential therapy with Mexidol 500 mg IV drip 1 time per day for 14 days followed by oral administration of Mexidol FORTE 250 1 tablet 3 times a day for 60 days indicate its clinical effectiveness and safety in patients with chronic cerebral ischemia with mild cognitive impairment, and also confirm its importance for preventing the progression of cognitive disorders.

Ethylmethylhydroxypyridine Succinate Is an Inhibitor but Not a Substrate of ABCB1 and SLCO1B1

2-Ethyl-6-methyl-3-hydroxypyridine succinate (EMHPS, Mexidol) is an original antioxidant and an anti-ischemic drug with the possibility of wide applications in the complex therapy of diseases, accompanied by the development of oxidative stress and ischemia; for example, ischemic stroke, chronic cerebral ischemia, and chronic heart failure. The use of EMHPS in the complex therapy of the above diseases may cause the development of drug-drug interactions, particularly pharmacokinetic interactions at the level of transporter proteins. In the present study, we evaluated the interaction of EMHPS with ABCB1 and SLCO1B1. In Caco-2 cells, it was shown that EMHPS is not a substrate of ABCB1 and that it does not affect its expression, but at the same time, it inhibits the activity of this transporter. Its inhibitory activity was inferior to verapamil-a classic inhibitor of ABCB1. In HEK293 and HEK293-SLCO1B1 cells, it was shown that EMHPS is not a substrate of SLCO1B1 either, but that it inhibited the activity of the transporter. However, its inhibitory activity was inferior to the classic inhibitor of SLCO1B1-rifampicin. Furthermore, it was found out that EMHPS does not affect SLCO1B1 expression in HepG2 cells. The approach proposed by the FDA (2020) and the International Transporter Consortium (2010) was used to assess the clinical significance of the study results. The effect of EMHPS on SLCO1B1 and the systemic inhibition of ABCB1 by EMPHS are not clinically significant, but ABCB1 inhibition by EMHPS in the gastrointestinal tract should be tested in vivo through clinical trials.

ANTIHYPOXIC ACTIVITY OF 2,6-DIMETHYLPYRIDINE-N-OXIDE

OBJECTIVE

The aim: To study the antihypoxic activity of 2,6-dimethylpyridine-N-oxide in mice using the various experimental models of acute hypoxia under orally or intraperitoneally administration.

PATIENTS AND METHODS

Materials and methods: The studies were performed on male CD-1 (SPF) mice. The antihypoxic activity of 2,6-dimethylpyridine-N-oxide was studied in three experimental models of acute hypoxia - hypercapnic hypoxia or hypoxia in a closed space, hemic hypoxia and histotoxic hypoxia at orally administration at doses 0.07; 7.1 and 71 mg/kg (respectively 1/20000, 1/200 and 1/20 of LD50) and at intraperitoneally administration at doses 7.1 and 71 mg/kg in comparison with reference drug Armadin.

RESULTS

Results: It is established, that 2,6-dimethylpyridine-N-oxide shows a antihypoxic activity in the all experimental models of acute hypoxia (hypoxia in a closed space, hemic hypoxia and histotoxic hypoxia). Its antihypoxic activity in acute hemic hypoxia and in acute hypoxia in a closed space was significantly higher than of reference drug Armadin, but during acute histotoxic hypoxia did not differ from Armadin. Also at intraperitoneal administration of 2,6-dimethylpyridine-N-oxide demonstrates less pronounced antihypoxic activity than at oral administration in all experimental models of acute hypoxia, but the coefficient efficiency is higher than in the reference drug Armadin.

CONCLUSION

Conclusions: 2,6-dimethylpyridine-N-oxide may be recommended for further detailed experimental studies as a perspective antihypoxant.

[Dopaminergic potential of domestic 3-hydroxypyridine and succinic acid derivatives and prospects for their therapeutic «retargeting»]

The review is devoted to the assessment of the pharmacological effects of 3-hydroxypyridine and succinic acid derivatives (emoxipin, reamberin and mexidol) from the standpoint of their dopaminergic activity. A systematic analysis of the data has been performed, allowing us to consider emoxipin, reamberin and mexidol as «normalizers of dopaminergic neurotransmission», the dopaminergic action of which in its phenotype corresponds to the effects of partial dopamine receptor agonists. The position that the dopaminergic effect, antioxidant and antidepressant potential of drugs containing 2-ethyl-6-methyl-3-oxypyridine (emoxipine and mexidol) are associated with their inhibitory effect on monoamine oxidase-A (MAO-A) has been substantiated. A direct relationship between the stimulating effect of succinate-containing drugs (reamberin and mexidol) on MAO-B, their prooxidant activity, insulin-potentiating and antidepressant effects was analyzed. A hypothesis has been put forward on the general pathological significance of dopaminergic regulation disorders, the correction of which with the 3-hydroxypyridine and succinic acid derivatives can be considered as a promising strategy for improving the complex therapy of socially significant and common human diseases.

[Possibility of application Mexidol for the treatment of patients suffering from sensorineural hearing loss and cerebrovascular insufficiency]

Sensorineural hearing loss can develop as a consequence of vascular pathology. The etiology and pathogenesis of chronic sensorineural hearing loss allow us to consider promising the use of neuroprotective drugs in the treatment regimen that can activate the function of the neural structures of the auditory pathway. Ethylmethylhydroxypyridine succinate, having complex pharmacological capabilities and a wide range of effects realized at the neural and vascular levels can be used in the treatment of hearing impairment and speech intelligibility.