Microcirculatory effects of a homeopathic preparation in patients with mild vertigo: an intravital microscopic study

Vertigoheel promotes rodent cognitive performance in multiple memory tests

Introduction

Cognitive impairment associated with old age or various brain disorders may be very disabling for affected individuals, placing their carers and public health services under considerable stress. The standard-of-care drugs produce only transient improvement of cognitive impairment in older people, so the search for novel, safe and effective therapeutics that would help to reverse or delay cognitive impairment is warranted. Repurposing pharmacological therapies with well-established safety record for additional indications is a promising recent trend in drug development. Vertigoheel (VH-04), a multicomponent drug made of Ambra grisea, Anamirta cocculus L., Conium maculatum, and Petroleum rectificatum, has been successfully used for several decades in the treatment of vertigo. Here, we investigated effects of VH-04 on cognitive performance in standard behavioral tests assessing different types of memory and explored cellular and molecular underpinnings of VH-04's biological activity.

Methods

In the majority of behavioral experiments, namely in the spontaneous and rewarded alternation tests, passive avoidance test, contextual/cued fear conditioning, and social transmission of food preference, we examined the ability of single and repeated intraperitoneal administrations of VH-04 to improve cognitive parameters of mice and rats disrupted by the application of the muscarinic antagonist scopolamine. In addition, we also assessed how VH-04 affected novel object recognition and influenced performance of aged animals in Morris water maze. Furthermore, we also studied the effects of VH-04 on primary hippocampal neurons in vitro and mRNA expression of synaptophysin in the hippocampus.

Results

Administration of VH-04 positively influenced visual recognition memory in the novel object recognition test and alleviated the impairments in spatial working memory and olfactory memory caused by the muscarinic antagonist scopolamine in the spontaneous alternation and social transmission of food preference tests. In addition, VH-04 improved retention of the spatial orientation memory of old rats in the Morris water maze. In contrast, VH-04 did not have significant effects on scopolamine-induced impairments in tests of fear-aggravated memory or rewarded alternation. Experiments in vitro showed that VH-04 stimulated neurite growth and possibly reversed the age-dependent decrease in hippocampal synaptophysin mRNA expression, which implies that VH-04 may preserve synaptic integrity in the aging brain.

Discussion

Our findings allow a cautious conclusion that in addition to its ability to alleviate manifestations of vertigo, VH-04 may be also used as a cognitive enhancer.

Vertigoheel improves central vestibular compensation after unilateral peripheral vestibulopathy in rats

The aim of this study was to assess the effect of Vertigoheel on central vestibular compensation and cognitive deficits in rats subjected to peripheral vestibular loss. Young adult male Long Evans rats were subjected to bilateral vestibular insults through irreversible sequential ototoxic destructions of the vestibular sensory organs. Vestibular syndrome characteristics were monitored at several time points over days and weeks following the sequential insults, using a combination of behavioral assessment paradigms allowing appreciation of patterns of change in static and dynamic deficits, together with spatial navigation, learning, and memory processes. Vertigoheel administered intraperitoneally significantly improved maximum body velocity and not moving time relative to its vehicle control on days 2 and 3 and on day 2, respectively, after unilateral vestibular lesion (UVL). It also significantly improved postural control relative to its vehicle 1 day after UVL. Conversely, Vertigoheel did not display any significant effect vs. vehicle on the severity of the syndrome, nor on the time course of other examined parameters, such as distance moved, mean body velocity, meander, and rearing. Spatial cognition testing using Y- and T-maze and eight-radial arm maze did not show any statistically significant difference between Vertigoheel and vehicle groups. However, Vertigoheel potentially enhanced the speed of learning in sham animals. Evaluating Vertigoheel's effect on thigmotaxis during the open-field video tracking test revealed no significant difference between Vertigoheel and its vehicle control groups suggesting that Vertigoheel does not seem to induce sedative or anxiolytic effects that could negatively affect vestibular and memory function. Present observations reveal that Vertigoheel improves central vestibular compensation following the unilateral peripheral vestibular loss as demonstrated by improvement of specific symptoms.

The effect of cinnarizine and cocculus indicus on simulator sickness

Pensacola Simulator Sickness Questionnaire (SSQ) is a valuable method to analyse symptoms evoked by exposure to a flight simulator environment that can also be adopted to evaluate the effectiveness of preventive tools, aiming at reducing simulator sickness (SS). In this study we analysed SSQ data in subjects undergoing a standard ground based spatial disorientation training inside a flight simulator, in order to evaluate the SS prevention obtained with two different pharmacological tools. Twelve males volunteers participated to an experimental design based on a double-blind, balanced administration of either 30 mg cinnarizine (CIN), or Cocculus Indicus 6CH (COC), or placebo (PLC) before one trial of about one hour spent inside a spatial disorientation trainer. All subjects underwent the three different conditions (CIN, COC, PLC) during 3 non-consecutive days separated by at least 2 weeks. During each experimental day, all subjects filled in SSQ. In addition, both postural instability (with the use of a static stabilometric platform), and sleepiness symptoms were evaluated. All the tests were performed before and after the simulated flight, at different times, in one-and-half-hour intervals. Results indicated a strong increase of sickness after flight simulation that linearly decreased, showing pre-simulator scores after 1.30 hours. In contrast to both PLC and COC, CIN showed significant side effects immediately following flight simulation, with no benefit at the simultaneous SSQ scores. Globally, no highly significant differences between COC and PLC were observed, although a minor degree of postural instability could be detected after COC administration. As far as the present exposure to a simulator environment is concerned, none of the pharmacological tools administered in this study resulted effective in reducing SS symptoms as detected by the SSQ. Moreover, CIN significantly increased sleepiness and postural instability in most subjects.