|Year : 2017 | Volume
| Issue : 1 | Page : 58-63
Homoeopathic medicine Mercurius solubilis treatment improves cerebral blood flow and memory in experimentally induced Dementia in rats
Kashif Hanif1, Manoj Kumar2, Neetu Singh1, Rakesh Shukla1
1 Division of Pharmacology, CSIR.Central Drug Research Institute, Lucknow, Uttar Pradesh; Academy of Scientific and Innovative Research, CSIR, New Delhi, India
2 Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
|Date of Web Publication||23-Feb-2017|
Division of Pharmacology, CSIR.Central Drug Research Institute, Lucknow, Uttar Pradesh; Academy of Scientific and Innovative Research, CSIR, New Delhi
Source of Support: None, Conflict of Interest: None
Background: Mercurius solubilis (Merc. sol) is a known, accepted homoeopathic medicine for the treatment of various mouth, throat, eye, and ear infections. Previous studies suggested that Merc. sol has anti-inflammatory properties which could be beneficial in memory impairment. Objective: The present study was designed to investigate the effect of Merc. sol on learning and memory and cerebral blood flow (CBF) in the rat model of impaired learning and memory function induced by intracerebroventricularly (ICV) administered streptozotocin (STZ). Materials and Methods: The different potencies of Merc. sol (6, 30, 200, and 1M) were given for 17 days in memory-impaired rats, induced by ICV administration of STZ (3 mg/kg). The Morris water maze test was used to evaluate the learning and memory function on the 14th, 15th, and 16th day. The laser doppler flow meter was used to measure CBF on the 17th day. Results: There was a significant reduction in CBF along with learning and memory functions in STZ (ICV)-treated rats, which were significantly attenuated by the treatment of Merc. sol at all potencies (6, 30, 200, and 1M). Conclusion: Our results demonstrated the effectiveness of Merc. sol in improving memory function and CBF. Thus, it could be used as a therapeutic agent in dementia.
Keywords: Cerebral blood flow, Cognitive dysfunction, Mercurius solubilis, Streptozotocin
|How to cite this article:|
Hanif K, Kumar M, Singh N, Shukla R. Homoeopathic medicine Mercurius solubilis treatment improves cerebral blood flow and memory in experimentally induced Dementia in rats. Indian J Res Homoeopathy 2017;11:58-63
|How to cite this URL:|
Hanif K, Kumar M, Singh N, Shukla R. Homoeopathic medicine Mercurius solubilis treatment improves cerebral blood flow and memory in experimentally induced Dementia in rats. Indian J Res Homoeopathy [serial online] 2017 [cited 2019 May 26];11:58-63. Available from: http://www.ijrh.org/text.asp?2017/11/1/58/200850
| Introduction|| |
Alzheimer's disease (AD), the most common cause of dementia, is associated with oxidative stress, inflammation, and cerebral endothelial dysfunction. Previous reports have shown that memory impairment is associated with poor cerebral blood flow (CBF), which may be involved in the progression of dementia, and these reports gave strength to the thought that a relationship exists between the memory and CBF  as increased CBF provides protection for cognitive disorders. Inflammation has been implicated as a common cause of various neurodegenerative diseases,, and evidence suggests that neuroinflammation and sustained increases in inflammatory cytokines in the central nervous system are closely correlated with cognitive dysfunction in the progression of AD., Previous studies have shown that anti-inflammatory drugs such as silibinin and ibuprofen ameliorate memory impairment by reducing oxidative stress and inflammation in mice brain.,,
Previous reports have proposed that the herbal medicines or products can be considered as a therapeutic approach to treat Alzheimer or other dementia-related disorders, showing cognitive impairment and neuroinflammation.Mercurius solubilis (Merc. sol) is a commonly used homoeopathic remedy for mouth-throat infections, catarrh, eye, ear infections, and fever. In homoeopathy, Merc. sol is also known as quicksilver or black oxide of mercury. In a previous study, Merc. sol has been found altering reactive oxygen species, reactive nitrogen species, and cytokine secretion, which improve wound healing and homoeostasis. Homoeopathic physicians also use Merc. sol for the treatment of various acute and chronic inflammatory conditions. A study by Vangoori et al., 2013 also showed that Merc. sol has anti-inflammatory property in acute and chronic experimental animal models of inflammation.
Intracerebroventricular (ICV) injection of streptozotocin (STZ) in rats leads to oxidative stress, inflammation, and impaired energy metabolism, resulting in progressive deficits in learning and memory and reduced CBF, which resembles various pathological characteristics of AD. As earlier studies have shown that Merc. sol possesses anti-oxidant and anti-inflammatory properties, therefore, the present study was designed to explore the effect of various potencies of Merc. sol (6C, 30C, 200C, and 1M) on the learning and memory and CBF on rat model of memory impairments induced by STZ.
| Materials and Methods|| |
Male Sprague–Dawley rats (230–250g) procured from the National Laboratory Animal Centre of CSIR-Central Drug Research Institute, Lucknow, India, were used in all experiments. They were allowed free access to food and water and maintained at 12 h day/night cycle (room temperature 24°C–27°C and humidity 60%–62%). The Institutional Animal Ethical Committee (IAEC, IAEC/2011/08 Renew 01 dated May 16, 2012) and Committee for the Purpose of Control and Supervision of Experiments on Animals - India guidelines were followed throughout the experiments.
Homoeopathic drug procurement
The Merc. sol was procured from Hahnemann Publishing Company Pvt. Ltd., Kolkata. We selected Merc. sol for this study as per the recommendations of the Scientific Advisory Committee, Central Council for Research in Homoeopathy, New Delhi. Authenticated samples of homoeopathic medicines in 6, 30, 200, and 1M potencies and absolute alcohol as vehicle were used for the experimental purpose.
Intracerebroventricular injection of Streptozotocin
STZ (3 mg/kg) was dissolved in artificial CSF (aCSF; 147 mM NaCl, 2.9 mM KCl, 1.6 mM MgCl2, 1.7 mM CaCl2, and 2.2 mM dextrose). The rats were anesthetized with chloral hydrate (300 mg/kg, i.p) and 10 μl volume of STZ was injected into each lateral cerebral ventricle (ICV) on days 1 and 3 using the coordinates: 0.8 mm posterior to bregma, 1.5 mm lateral to sagittal suture, 3.6 mm ventral using Hamilton microsyringe.,
Merc. sol potencies of 6C, 30C, 200C, and 1M were prepared in a dilution of 1:10 with distilled water and administered orally. The rats were divided into six groups and each group had six rats [Table 1].
|Table 1: Treatment schedule for Mercurius solubilis treatment in streptozotocin-treated rats|
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Evaluation of learning and memory
The learning and memory function was evaluated by Morris water maze test in rats., This consisted of a video capturing system, with a large circular black vessel of 120 cm diameter, 50 cm heights, filled to depth of 30 cm with water at 26 ± 2°C; containing four virtual quadrant points as north, east, south, and west. A round platform (black, 8 cm diameter) was placed below the surface (1 cm) of water in the middle of the northeast quadrant in the pool. The starting point was in the southwest quadrant in all the trials. Latency time to reach the platform was measured and recorded on accomplishment of each trial. The cutoff time was set to 120 s for rats to find the hidden platform and stay on it for 30 s. For evaluation of learning and memory, rats chronically treated with different potencies of Merc. sol were subjected to Morris water maze trial from 14th to 16th day. Latency time to reach the platform was recorded in each trial and significant decrease in latency time was considered as successful learning.
Measurement of cerebral blood flow
CBF was measured using a laser Doppler flowmetry (LDF 100, Biopac, USA) which is equipped with a tiny microfiber laser probe of 2 cm length and 0.5 mm diameter., To measure CBF, the point was made by drilling using stereotaxic instrument (1 mm posterior and 6 mm lateral to bregma) on the skull of anesthetized rats (chloral hydrate, 300 mg/kg, i.p). A laser probe was placed on the point on the skull of rats. Then probe was attached to LDF for 45 min. Blood flow meter qualitatively measures blood flow in arbitrary blood perfusion units (BPUs).
The results were expressed as mean ± standard error of the mean. The two-way of analysis of variance (ANOVA) followed by Bonferroni's multiple comparison test was used to analyze Morris water maze results, and one-way ANOVA followed by Bonferroni's comparison test was used for CBF (BPU). The P < 0.05, P < 0.01, and P < 0.001 were considered statistically significance.
| Results|| |
Effect of Mercurius solubilis on impaired memory function in Streptozotocin-treated Rats
There was no significant decrease in the latency time of first- and second-retention trial as compared to acquisition trial in sham group. Impairment in learning and memory function was found in the STZ-treated group as evident by no change in the latency time of acquisition trial and first- and second-retention trials. The treatment for 17 days with Merc. sol 6 (F [2, 15] = 14.9, P < 0.001), Merc. sol 30 (F [2, 9] = 26.15, P < 0.001), Merc. sol 200 (F [2, 12] = 18.7, P < 0.001), and Merc. sol 1M (F [2, 9] = 23.32, P < 0.001) reduced latency time of first- and second-retention trials as compared to acquisition trial, respectively, in STZ-treated rats [Figure 1]a. There was no significant effect of alcohol which was used as a vehicle on latency time of STZ-treated rats.
|Figure 1: Effect of Mercurius solubilis on (a) latency time (s), (b and c) mean path length (cm) in memory impaired (dementic) Sprague–Dawley rats. Memory deficit was induced by intracerebroventricular administration of streptozotocin (3 mg/kg) and treated with different potencies of Mercurius solubilis (6, 30, 200, and 1M) for 17 days in rats. Latency time and path length were evaluated by Morris water maze test on 14th, 15th, and 16th day (*P < 0.05, **P < 0.01, ***P < 0.01 vs. acquisition trial)|
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The results obtained from latency time were also confirmed by the path length results. The STZ-treated rats showed memory impairment as evident by longer path length in acquisition trial and first- and second-retention trials in comparison of sham rats. The treatment with Merc. sol 6 (F [2, 15] = 6.6, P < 0.05), Merc. sol 30 (F [2, 9] = 20.59, P < 0.001), Merc. sol 200 (F [2, 12] = 15.0, P < 0.001), and Merc. sol 1M (F [2, 9] = 17.8, P < 0.001) treated rats have shown shorter path length in the first- and second-retention trials as compared to acquisition trial in STZ-treated rats [Figure 1]b and [Figure 1]c.
Effect of Mercurius solubilis on cerebral blood flow in Streptozotocin-treated Rats
A significant decrease was observed in CBF in STZ-treated rats (328.3 ± 5.2 BPU, P < 0.001) as compared to the sham rats (493.6 ± 19.7 BPU). There was a significant improvement observed in CBF in Merc. sol 6 (400.1 ± 5.9 BPU, P < 0.001), Merc. sol 30 (1061 ± 11.0 BPU, P < 0.001), Merc. sol 200 (531.3 ± 9.3 BPU, P < 0.001), and Merc. sol 1M (557.1 ± 4.3 BPU, P < 0.001) as compared to STZ-treated rats [Figure 2], being the result obtained after Merc. sol 30 treatment 100% above the control parameters.
|Figure 2: Effect of Mercurius solubilis on cerebral blood flow in memory impaired Sprague–Dawley rats. Memory deficit was induced by intracerebroventricular administration of streptozotocin (3 mg/kg) and treated with different potencies of Mercurius solubilis (6, 30, 200 and 1M) for 17 days in rats. Cerebral blood flow was measured by laser Doppler flowmetry on the 17th day (***P < 0.001 vs. streptozotocin and +++P < 0.001 vs. sham group)|
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| Discussion|| |
The present study examined the effect of Merc. sol on memory impairment and CBF in STZ-administered rats. Pretreatment with different potencies of Merc. sol in STZ-administered rats improved learning and memory functions along with CBF in the rat brain, suggesting the protective role of Merc. sol in memory impairment.
In the present study, there was no significant decrease in latency time and path length in STZ-treated rats, indicating memory impairment which was also supported by previous reports., In cognitive disorders such as AD, memory impairment has been linked to the inflammation in brain tissue. Previous studies have shown that reduction in inflammatory cytokines or inflammation is beneficial in the treatment of dementia., Administration of different potencies of Merc. sol (6, 30, 200, and 1M) attenuated STZ-induced memory deficit as evidenced by reduced latency time and path length as compared to control. Studies by Vangoori et al., 2013 and S Shadfar et al., 2015 have shown that Merc. sol has anti-inflammatory properties which may be one of the reasons behind the improvement in memory function in Merc. Sol-treated rats as compared to STZ-treated rats.,
Decreased CBF is also responsible for the impairment in the memory function as several reports showed the disturbed CBF in the patients of AD and other cognitive diseases. A significant reduction in CBF was found in STZ-injected rats along with impaired memory function in present work. This finding is in conformity with our earlier work, in which STZ treatment impaired learning and memory function along with decreased CBF. In the present study, all the potencies of Merc. sol (6C, 30C, 200C, and 1M) significantly reversed the decline in CBF caused by STZ. However, the result obtained after Merc. sol 30 treatment was 100% above the normal parameters found in untouched control.
The anti-inflammatory property of Merc. sol can be the reason behind the improvement in CBF in STZ-treated rats although more specific research protocols are needed to highlight this hypothesis.
| Conclusion|| |
The present study supported findings that disturbed cerebral circulation is associated with impaired memory functions as evidenced by decreased CBF following STZ.,Merc. sol treatment offered protection in memory impairment along with an increase in CBF, which may be one of the reasons for its beneficial effect. This neuroprotective protective effect may be due to its anti-inflammatory properties as suggested by previous reports., Therefore, the mechanism underlying protective effect of Merc. sol is required to explore to treat cogitative disorder.
Financial support and sponsorship
We would like to appreciate the financial support from the Central Council for Research in Homoeopathy (CCRH), New Delhi.
Conflict of interest
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[Figure 1], [Figure 2]