|PRE - CLINICAL STUDY: ORIGINAL ARTICLE
|Year : 2021 | Volume
| Issue : 3 | Page : 155-162
Evaluation of polyherbal formulation for antihypertensive activity in albino rats
Pratibha, Gaurav Sharma, Sudipta Kumar Rath
Department of Dravyaguna, NIA Deemed to be University, Jaipur, Rajasthan, India
|Date of Submission||18-Dec-2020|
|Date of Decision||15-Feb-2021|
|Date of Acceptance||28-Mar-2021|
|Date of Web Publication||25-Sep-2021|
Department of Dravyaguna, NIA (Deemed to be University), Jaipur, Rajasthan
Source of Support: None, Conflict of Interest: None
Background: Hypertension (HTN) is a multifactorial clinical condition and therefore can be managed in multiple pathways. Long time period use of modern antihypertensive drugs is associated with a spectrum of toxic and side effects. Modern antihypertensive drugs are not ideally effective owing to dependence, side effects, and cost. However, therapeutic interventions using herbal drugs for HTN have gained widespread attention worldwide. Aim: The aim of the study is to evaluate the antihypertensive activity of polyherbal formulation (NIA/DG/2015/01) as an adjuvant with modern antihypertensive drug or as a stand-alone drug in cadmium chloride (CdCl2)-induced hypertensive albino rat model. Methods: The polyherbal formulation (NIA/DG/2015/01) comprises the bark of Terminalia arjuna (Roxb.) W and A, the root of Withania somnifera (Linn.), the rhizome of Nardostachys jatamansi DC., the root of Boerhaavia diffusa (Linn.), and whole plant of Convolvulus pluricaulis Choisy. All the herbs were separately extracted in aqueous medium. Polyherbal formulation (90 mg/kg., p.o.), was evaluated using the CdCl2-induced hypertensive rat model using the Verapamil as a standard reference drug. HTN was induced in albino rats by intraperitoneal administration of CdCl2 (0.1% CdCl2 solution) 1 mg/kg/day for 15 days. After 15 days, intervention was started for 28 days, and blood pressure (B.P.) was measured in every 7th day. Results: Polyherbal formulation significantly reduced (P < 0.001, one-way analysis of variance followed by Tukey's multiple comparison test and Dunnett's multiple comparison test) systolic and diastolic B.P. in CdCl2-induced HTN model when compared with Verapamil. Conclusion: Polyherbal formulation (NIA/DG/2015/01) possesses significant antihypertensive activity.
Keywords: Antihypertensive, Boerhaavia diffusa, cadmium chloride, Convolvulus pluricaulis, hypertension, polyherbal, Terminalia arjuna, Withania somnifera
|How to cite this article:|
Pratibha, Sharma G, Rath SK. Evaluation of polyherbal formulation for antihypertensive activity in albino rats. J Ayurveda 2021;15:155-62
|How to cite this URL:|
Pratibha, Sharma G, Rath SK. Evaluation of polyherbal formulation for antihypertensive activity in albino rats. J Ayurveda [serial online] 2021 [cited 2022 May 19];15:155-62. Available from: http://www.journayu.in/text.asp?2021/15/3/155/326714
| Introduction|| |
Hypertension (HTN) is a significant risk factor for the development of cardiovascular disorders and cerebrovascular disease causing the high rate of mortality and morbidity. It mainly causes stroke and end-stage renal failure. It is also responsible for the development of coronary artery disease. It is asymptomatic but produces terrible effects on the body. Hence, it is miles referred to as silent or hidden killer. Due to its high prevalence in the nation, India is known as nation of HTN.
HTN, additionally, referred to as high or raised blood pressure (B.P.), is a circumstance wherein the blood vessels have persistently raised pressure, and includes both HTN (defined as 140/90 mm of Hg or above) and “high normal” (between 130/85 mm of Hg and 140/90 mm of Hg). It is classified as either primary (essential) or secondary. About 90% to 95% of instances are termed primary HTN, which refers to high B.P. that no medical cause can be found. The remaining 5% to 10% of cases, referred to as secondary HTN, are due to different conditions that affect the kidneys, arteries, heart, or endocrine system. The prevalence of HTN in the urban Indian population was predicted to be 40.8% (95% confidence interval [CI]: 40.5%–41.0%) and that of HTN in the rural population was 17.9% (95% CI: 17.5%–18.3%).
Globally, the general prevalence of HTN or raised B.P. in the elderly 25 and above was around 40% in 2008. Worldwide, HTN is estimated to cause 7.5 million deaths, about 12.8% of the total deaths. HTN accounts for 57 million disability-adjusted life years (DALYs) or 3.7% of total DALYs. The World Health Organization has estimated that globally approximately 62% of cerebrovascular disorders and 49% of ischemic heart diseases are a consequence of suboptimal B.P. (systolic >115 mmHg), with little variation by sex. Elevated B.P. is present in one in three adults worldwide. HTN increases the chance of heart attack, stroke, nephropathy, and many other associated comorbidities. Treating raised B.P. and maintaining it below 140/90 mmHg are associated with reducing cardiovascular complications.
Although antihypertensive class of drugs was discovered more than 60 years ago, the multifactorial nature of the disease poses a severe challenge in the management of HTN. Lifelong dependence on drugs, associated ADRs of antihypertensive drugs, development of resistance to antihypertensives, failure to bring normtension despite multiple antihypertensives, etc., of the significant issues related to antihypertensives. Ayurveda adopts a holistic approach which logically suits better for multifactorial diseases such as HTN.
There is a renewed interest in traditional medicines such as Ayurveda to find some holistic solution to this health menace. In general, HTN is managed in Ayurveda with herbs having Vata-pitta Shamaka action and affinity to central nervous system and cardiovascular system. In other words, herbs having antihypertensive, stress-reducing, cardiotonic, diuretic, and antioxidant actions are used to manage this condition. A large population is now seeking integrated management of HTN, i.e. modern antihypertensives along with Ayurvedic medicines. In practice too, it is not sensible to withdraw antihypertensives immediately as uncontrolled HTN can cause severe organic damage. Therefore, the most generally adopted antihypertensive approach has been to combine Ayurvedic medicines with modern antihypertensives and gradually withdraw the modern medicines. However, there is hardly any data available to assess the role and effectiveness of such an integrated approach logically. There is thus a need for creating a systematically generated evidence body for this approach of antihypertensive management.
The need for study:
- Modern antihypertensive drugs are not ideally effective owing to dependence, side effects, and cost
- Ayurvedic medicines do play a role in the management of HTN but practically as adjuvant therapy because of the serious emergency consequences of uncontrolled HTN
- Although practically adopted, there is very little scientific and systemic data available for the role and efficacy of Ayurvedic medicines as an adjuvant therapy in HTN. Although many Ayurvedic herbs are used for HTN management, a holistic formulation containing ingredients that can address all possible pathways of HTN is not available in the market.
Against this background, the present study was planned to assess the role of Ayurveda medicines as an adjuvant therapy and stand-alone management in HTN in the albino rat model.
Hence, in the proposed study, polyherbal formulation (NIA/DG/2015/01) is a hypothetical Ayurvedic formulation which contains aqueous extract of Arjuna bark, Ashwagandha root, Jatamansi rhizome, Punarnava root, and Shankhapushpi whole plant which are already reported to possess hypotensive or antihypertensive effect individually and act through a different mechanism [Table 1].,,,,
The main objective of the present study is to prepare novel polyherbal formulation, which can give antihypertensive effect both as an adjuvant with modern antihypertensive drug or as a stand-alone drug in the experimentally induced HTN in rats. Another object is to provide unique formulation, which can control HTN by a different mechanism so that better effectiveness can be achieved.
| Methods|| |
The experimental study was conducted on albino Wistar rats at Institute of Biomedical and Industrial Research, Vidhyadhar Nagar, Jaipur, after getting due approval from its Institutional Animal Ethical Committee vide Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA) Approval No: 1737/PO/RC/S/14/CPCSEA, IAEC No: IBIR/CPCSEA/IAEC/2015/2/4.
A total of 30 Wistar albino rats, weighing 200–250 g, were used during experimental study. Animals were fed with standard chow diet. All animals were kept under a controlled light/dark cycle. Each of 12 h, temperature (22°C ± 2°C) and humidity (50%–60%) with free access to food and water ad libitum animals fasted for the prescribed time in the individual models before antihypertensive activity. Throughout the experiment, the animal house was maintained within conditions as per the standard guidelines of CPCSEA of India.
Preparation of polyherbal formulation: (Test formulation)
In all plants were procured from a natural source and identified by botanical survey of India, Jodhpur. All mentioned plants were dried and grounded to a coarse powder. 100 g powdered (20 g of each drug) drug was extracted with 2000 ml of water using a Soxhlet apparatus (Hot extraction method) for 72 h. At the end of extraction, the extract was concentrated, and the solvent was evaporated in a petri dish with the help of a water bath. The thick and sticky paste thus was obtained, and it was stored in airtight container at room temperature till further use and this extract was used as a test drug [Figure 1] and [Figure 2].
Acute oral toxicity study
The acute oral toxicity study was carried out as per the Organization for Economic Co-operation and Development (guidelines 423) received from the CPCSEA.
The model used to evaluate the antihypertensive activity
Cadmium chloride (CdCl2)-induced HTN in albino Wistar rats model was used for experimental study.
Thirty albino Wistar rats of both sexes of 5 groups (A, B, C, D, and E) were administered 1 mg/kg/day intraperitoneal (0.1% CdCl2 solution) CdCl2 for 15 days for inducing HTN. After 15 days of test formulation, standard drug and critical micelle concentration (CMC) solution had administered orally with the help of oral feeding tube for 28 days. After inducing HTN, treatment was done by the following group [Table 2].
B.P. was measured in every 7th day using the tail-cuff method using a Harvard noninvasive B.P. apparatus, and at 28th day, blood samples were collected from orbital puncture for analysis of high-density lipoprotein (HDL) and serum triglycerides.
Test drug dose calculated for experimental albino rats
Test dose was derived from acute toxicity study. The suitable dose for an albino rat was calculated by referring to the table of Paget and Barnes. The dose of extract for albino rat was calculated 90 mg/Kg body weight of albino rat.
The observed data had been recorded and presented in tabular format. These data have been analyzed to establish patterns of results. All values were represented in terms of mean ± standard error of the mean. After completion of the study, one-way ANOVA followed by Tukey's multiple comparison test and Dunnett's multiple comparison test was applied to check the level of significance using GraphPad prism software. P <0.05 was considered as a statistically significant activity.
| Results|| |
Acute oral toxicity study
In the acute toxicity study, the administration of the polyherbal formulation (NIA/DG/2015/01) at 300 and 2000 mg/kg/body weight did not elicit any mortality up to 2000 mg/kg dose in the rat model. There were no gross behavioral changes or any clinical symptoms observed. There was no lethal or toxic effect seen in any of the animals.
No significant changes in B.P. were observed in Group A (Negative control) in all observations [Table 3] and [Table 4].
| Discussion|| |
The present study shows that herbal formulation (NIA/DG/2015/01) has a significant antihypertensive effect in experimentally induced hypertensive models.
- The study was conducted in 5 groups comprising Group A - animals received no medication but were given 5% CMC solution, Group B - animals received aqueous extract of formulation 90 mg/kg body weight twice daily, Group C - animals received Verapamil 15 mg/kg/day orally. Group D (adjuvant) - animals received test formulation + Verapamil with constant dose. Group E (adjuvant with reducing the dose of positive control) received a constant dose of test formulation, but positive control drug reduced in 1/4th tapering dose for 1 week then reduced gradually. The test formulation (NIA/DG/2015/01) and other drugs were administered orally for 28 days. The observations were recorded at 0, 7, 14, 21, 28, and 35th day on parameters of B.P. and lipid profile
- As could be seen in observation [Table 5], Group B showed a significant reduction in DBP on 7th day (P = 0.0001, 13.22%) whereas no significant reduction was observed in SBP on the same day. However, a highly significant reduction in both DBP and SBP was observed in this group on 14th, 21st, and 28th day, as shown in [Table 5]. It is also observed that after the withdrawal of the test formulation, the B.P. went back to the levels on B.P. on 0 day
- As could be observed [Table 6], it is seen that the Group B reduced DBP in a highly significant manner from 7th day onward to 28th day as compared to the negative control (Group A) [Graph 1] and [Graph 2].
|Table 5: Differences in blood pressure in Group B (test formulation) with respect to days of drug administration|
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|Table 6: Differences in blood pressure in Group B (test formulation) with respect to Group A (negative control)|
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Group B did not decrease S.B.P. significantly on 7th day, whereas it reduced SBP highly significantly from 14th day to 28th day as compared to negative control. Therefore, it could be logically said that the test formulation has a significant role in reducing HTN in CdCl2-induced hypertensive rat model.
- In Group C [Table 7] and [Table 8], the positive control group, B.P., was reduced significantly from 7th day to 28th day. In this group also upon withdrawal of the drug, the B.P. increases back to the level of day 0. The test formulation was almost equally effective in reducing DBP and SBP as compared to that of the positive control. This reduction in B.P. is highly significant in both test formulation and positive control, but positive control showed percentage-wise better efficacy than the test formulation
- In Group D [Table 9] and [Table 10], positive control distinctively and almost immediately reduces B.P. was given the test formulation to explore possible better effects of the test formulation as an adjuvant. However, it was seen that only till 7th day, the effects in Group D were significantly better than Group B. However, the differences in activity were found to be nonsignificant from 14th day onward. Therefore, it seems that from 14th day onward, i.e. when the reduction of B.P. comes back to a normal level with the test formulation, no added benefit could be observed by adding the positive control. It may be suggested that depending on the clinical condition, the positive control could be given along with the test formulation till 2 weeks
- In Group E, it was planned to withdraw the positive control in a phased manner to establish the effects of the test formulation sustainably. However, during the experiment, the test formulation could restore B.P. to normal levels by 14th day itself and at a comparable percentage with that of positive control. It was also further observed that positive control and the test formulation did not improve or deteriorate their individual effects when given in combination
- Therefore, as could be seen in [Table 11], the gradual reduction in the dose of positive control when given along with test formulation did not show any significant change in their effect on B.P
- Lipid profile - no significant changes were observed in serum triglycerides and HDL on day 28th in all groups concerning to Group A (negative control) [Table 12].
|Table 7: Differences in diastolic blood pressure in Group B (test formulation) versus Group C (positive control) with respect to Group A (negative control)|
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|Table 8: Differences in systolic blood pressure in Group B (test formulation) versus Group C (positive control) with respect to Group A (negative control)|
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|Table 9: Differences in diastolic blood pressure in Group B (test formulation) versus Group D (adjuvant) with respect to Group A (negative control)|
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|Table 10: Differences in systolic blood pressure in Group B (test formulation) versus Group D (adjuvant) with respect to Group A (negative control)|
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|Table 11: Effect of reduction of dose of positive control (Group D vs. Group E)|
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|Table 12: Lipid profile (high.density lipoprotein, serum triglycerides) in all groups|
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| Conclusion|| |
Based on the observations recorded in the present work and analysis, thereof the study team suggest that:
- The test formulation (NIA/DG/2015/01) was safe when given at 300 mg/kg body weight and 2000 mg/kg body weight in albino rats
- The test formulation was found to be significantly effective in reducing B.P. in CdCl2-induced hypertensive rats when given at the 90 mg/kg body weight twice daily from 14th day onward
- The test formulation could not sustain its effect in reducing B.P. upon its withdrawal on 28th day
- The positive control, i.e. the modern antihypertensive drug showed no synergistic effect with the test formulation in reducing B.P
- Since the test formulation normalizes B.P. after 2 weeks, the positive control, i.e. modern antihypertensive drugs, may be given along with the test formulation.
Future research directions/prospective
Further studies are being planned to confirm this formulation's mechanism in various animal models.
I would like to acknowledge and express my deepest gratitude to the most dynamic paragon, ingenious, exceedingly precious my supervisor Dr. Sudipta Kumar Rath. His collaboration, keen observation, valuable suggestion, and close involvement with this work gave me considerable confidence to accelerate and complete my work. I am grateful to my co-supervisor, Mr. Gaurav Sharma, for his constant support and guidance throughout the preparation of this dissertation.
Financial support and sponsorship
The authors are grateful to National institute of Ayurveda for providing funding and all necessary facilities to carry out the research work.
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10], [Table 11], [Table 12]