|Year : 2014 | Volume
| Issue : 2 | Page : 64-67
Analgesic and anti-inflammatory effects of aqueous extract of leaves of Pentatropis capensis Linn. f. (Bullock)
Saikat Chowdhury1, K Nishteswar1, Mukesh Kumar Nariya2
1 Department of Dravyaguna, Institute of Post Graduate Teaching and Research in Ayurveda, Gujarat Ayurved University, Jamnagar, Gujarat, India
2 Department of Pharmacology Laboratory, Institute of Post Graduate Teaching and Research in Ayurveda, Gujarat Ayurved University, Jamnagar, Gujarat, India
|Date of Web Publication||18-Mar-2015|
Department of Dravyaguna, Institute of Post Graduate Teaching and Research in Ayurveda, Gujarat Ayurved University, Jamnagar - 361 008, Gujarat
Source of Support: None, Conflict of Interest: None
Background: Herbal analgesic and anti-inflammatory remedies are preferred much because of lesser side effects and also a lower tendency for habit formation. Pentatropis capensis is such an analgesic and anti-inflammatory drug which is popular among folklore remedies for various injuries and inflammatory problems. It is called by the name of Kākanāsikā in Ayurvedic works. This study was designed to investigate the analgesic, and anti-inflammatory effects of aqueous extract of P. capensis leaves (AEPC) in rats.
Materials and Methods: AEPC was assessed for Analgesic effect through radiant heat tail-flick model and anti-inflammatory effect through carrageenan-induced paw edema model on Wistar strain of albino rats.
Results: Pentatropis capensis leaves aqueous extract showed significant (P < 0.001) increase in the duration of latency of tail flick response at the dose levels of 450 mg/kg, p.o. as compared to the control group. Similarly, the similar dose level produced significant (P < 0.01) anti-inflammatory effect against acute paw edema after 3 h of carrageenan induction when compared to the control group.
Conclusion: The observed effects were comparable with the standard drug-treated group thus demonstrating effective central analgesic and acute anti-inflammatory potentials of the P. capensis leaves aqueous extract and the observations substantiate its folklore use as an analgesic and anti-inflammatory.
Keywords: Carrageenan, paw edema, Pentatropis capensis, plethysmograph, tail flick response
|How to cite this article:|
Chowdhury S, Nishteswar K, Nariya MK. Analgesic and anti-inflammatory effects of aqueous extract of leaves of Pentatropis capensis Linn. f. (Bullock). Ancient Sci Life 2014;34:64-7
| Introduction|| |
Pain is an unpleasant, sensory, and emotional experience associated with actual or potential tissue damage. It acts as a warning signal against disturbances in the body and thus has a protective action in many cases.  Inflammation is a local response of living vascularized connective tissue to injury caused by various exogenous and endogenous factors which arise as protective and restorative responses in order to eliminate or limit the spread of the injurious agents as well as to remove the consequent necrosed cells and tissues to begin the healing process. 
Many drugs are available which help to relieve pain and reduce inflammation. They act by interfering with various chemical mediators; however, they are not without side effects when used at higher doses. Risks include upper gastrointestinal bleeding and perforation associated with nonsteroidal anti-inflammatory drugs (NSAIDs) and physical dependence and abuse liability developed by opiates.  These problems have led to a search for potent analgesic and anti-inflammatory drugs from plant sources as alternatives to NSAIDs and opiates.
Many Indian medicinal plants are reported to be useful in pain and inflammation. Among those, Pentatropis capensis is one of the popular ethnomedicinal plants and many of its ethnomedicinal uses include; taking warm leaf juice as nasal drops to alleviate headache, running nose, and body ache,  leaves of this plant are boiled with coconut oil and externally used in cuts and wounds  and also effective in upper respiratory infection.  In Ayurvedic works, this plant is called as Kākanāsikā. A literature survey concerning P. capensis confirmed the presence of various bioactive phytochemical constituents such as n-octacosanol, α-amyrin, friedelin, β-sitosterol, and salicylic acid.  A review of P. capensis from different floras, databases, and periodicals substantiated that the anti-inflammatory, analgesic properties of aqueous extract of leaf using animal models have not yet been evaluated. Keeping this in view, the present study was carried out using in-vivo anti-inflammatory and analgesics models with aqueous extract of P. capensis (AEPC) leaf. The present study may help to develop an effective drug for the treatment of algesia and inflammatory related ailments.
| Materials and Methods|| |
Plant materials collection and authentication
The whole plant was collected from Talabar Chakri of Jamnagar district, Gujarat, India; during morning time when the plant was in the flowering stage in the month of September. For authentication of the plant drug, twig containing leaves and flowers were collected. The specimen were disease free with all parts intact without any injuries and herbarium sample was prepared and were sent to Central National Herbarium (CNH), Botanical Survey of India, Shibpur, Howrah, West Bengal, India. The samples were identified as P. capensis Linn. f. (Bullock), family Apocynaceae (according to angiosperm phylogeny Groups I, II, and III classification) and Asclepiadaceae (According to Bentham and Hooker classification) and preserved in the Department of Dravyaguna (voucher specimen number is CNH/86/2012/Tech. II/917). After authentication, the leaves were separated from the collected plant materials and shade-dried at room temperature and were pulverized in mixer grinder to coarsely powdered drug and passed through sieve 80 and stored in a sealed container for the further use.
Processing and extraction
Leaves were collected from plants and cleaned properly, separately shade-dried and powdered. The powdered leaves were extracted in percolator apparatus using distilled water and placed for 24 h in a sterile atmosphere. The extract was concentrated by drying with the help of water-bath to yield dried aqueous extract of leaves.
Totally, 36 Wistar strain albino rats of either sex weighing between 180 ± 20 g were used for the experiments and randomly divided into three groups of six rats for each experiment. The animals were obtained from the animal house attached to I.P.G.T. and R.A., Gujarat Ayurved University, Jamnagar. The animals were housed cages made up of polypropylene with stainless steel top grill. The selected animals were kept under acclimatization for 7 days before dosing. The animals were exposed to 12 h light and 12 h dark cycle with the relative humidity of 50-60% and the ambient temperature was 22 ± 03°C during the period of experimentation. Animals were fed with Amrut brand rat pellet feed supplied by Pranav Agro Mills Pvt. Limited. The drinking water was given ad libitum. The experimental protocols were approved by Institutional Animal Ethics Committee (IAEC/13/2013/10) in accordance with the guideline formulated by CPCSE, India.
The rats were divided into three groups of six rats and groups are as follows:
- Group I: Control group, received vehicle orally as an aqueous suspension of 1% carboxy methyl cellulose (CMC) 10 ml/kg body weight
- Group II: Drug-treated group, received AEPC at therapeutic equivalent dose (TED) of 450 mg/kg body weight in 1% CMC, orally (p.o./os)
- Group III: Standard group received pentazocine at dose of 20 mg/kg intra-peritoneal (i.p.).
Acute nociception was assessed by a tail flick apparatus (INSIF-Ambala, India) following the method introduced by D'Amour and Smith.  Each animal was placed in a restrainer 2 min before treatment, and baseline reaction time was measured by placing the fixed part of the tail on the radiant heat source. The tail withdrawal from heat (flicking response) was taken as the end point. Animals were treated with above-scheduled doses and later the postdrug reaction time was measured at 30 min, 60 min, 120 min, and 180 min. A cut-off period of 15 s was observed to avoid damage to the tail. Results were expressed as a percentage increase in tail flick latency in comparison to the control.
The rats were divided into three groups of six rats and each group as follow:
- Group I: Control group, received vehicle as an aqueous suspension of 1% CMC 10 ml/kg body weight, orally.
- Group II: AEPC at TED of 450 mg/kg body weight in 1% CMC, orally (p.o.)
- Group III: Standard group animals received phenylbutazone at dose of 100 mg/kg orally (p.o.).
The test drug was administered once daily for five consecutive days. The standard drug phenylbutazone (100 mg/kg; p.o.) dissolved in 1-2 drops of 5% NaOH solution and adding distilled water followed by neutralizing the pH of the solution. On the 5 th day, prior to carrageenan injection, the initial paw volume of the left hind paw up to the tibia-tarsal articulation was measured using a plethysmograph (model 520, IITC Life Science Inc.,). One hour after drug administration edema was produced by injecting 0.1 ml freshly prepared 1% w/v carrageenan in sterile saline solution into the sub-plantar aponeurosis of the left hind limb. 
The rats were administered distilled water in the dose of 2 ml/100 g; p.o. body weight to ensure uniform hydration and hence to minimize variations in edema formation. The intensity of edema formation was recorded after 1, 3, and 5 h of carrageenan injection. Results were expressed as per following equation.
The data generated during the study were expressed as mean ± standard error of the mean. The data were statistically analyzed by Student's unpaired and paired t-test for determining significant difference between groups at P < 0.05. All data were calculated by using software "SigmaStat 3.1" Systat Software, CA, USA.
| Results and Discussion|| |
Radiant heat tail-flick model
In radiant tail flick test, the plant extract prolonged the pain tolerance capacity of the rat more significantly compared to the control group when given therapeutically equivalent dose of human [Table 1]. Pretreatment with the leaf extract (450 mg/kg; p.o.) produced significant effects in tail flick latency time compared to control group throughout the experiment. When values of tail flick response at different time intervals in control group were compared with initial values, it was found that the rats were more sensitive toward radiant heat pain which was confirmed by reduction in tail flick time [Table 1]. However, in leaf extract-treated group, the tail flick time increased at different time intervals compared to initial values which suggest the resistance of rats towards radiant heat pain.
|Table 1: Effects of crude extract on radiant heat tail flick response in rats at different time intervals |
Click here to view
The result indicates that leaf extract of P. capensis at the dose 450 mg/kg body weight (p.o.) has central analgesic effect which is significant when compared to the control group. The radiant heat tail-flick model is used for screening of centrally acting analgesics where tail flick to noxious thermal stimuli is mediated via supraspinal centers.  Pro-inflammatory mediators such as prostaglandins and bradykinin have been suggested to play an important role in algesia.  The analgesic effect of P. capensis leaves might be attributed to decrease in prostaglandin generation leading to less sensitization of nociceptive nerve endings to inflammatory mediators such as bradykinin, 5-hydroxytryptamin, and cytokines.
Carrageenan-induced paw edema
Carrageenan-induced inflammation in the rat paw represents a classical model for studying the acute inflammation and was used for evaluation of anti-inflammatory activity of AEPC. In the carrageenan-induced rat paw edema, reference drug phenylbutazone (100 mg/kg; p.o.) and the AEPC (450 mg/kg; p.o.) showed a significant inhibition (47.24 ± 6.92 (P < 0.05) and 22.51 ± 9.99 (P < 0.01), respectively) of edema at the end of 3 h [Table 2]. The test drug showed more significant reduction of paw edema on experimental animals than the reference standard, phenylbutazone when compared with the control group. The test drug also reduced the percentage increase in paw edema after 1 h as compared to the control group, but the effect was statistically insignificant.
|Table 2: Effect of leaf extract of P. capensis on Carrageenan induced paw oedema at different time interval |
Click here to view
The carrageenan-induced rat paw edema is a biphasic process.  The release of histamine or serotonin occurs in the first phase (up to 2 h) and the second phase (2-6 h) is associated with the production of bradykinin, protease, prostaglandin, and lysosome.  Therefore, the inhibition of carrageenan-induced inflammation by the leaf extract of P. capensis due to the inhibition of the enzyme cyclooxygenase and subsequent inhibition of prostaglandin production and thromboxanes. The decrease in prostaglandin E 2 and prostacyclin reduces vasodilatation and ultimately subsidize edema.
| Conclusion|| |
In the present study, the AEPC leaf has demonstrated a significant central analgesic and acute anti-inflammatory effect which validates the folklore use of this plant in various cut injuries, wounds including inflammatory diseases. There is a need for further studies to explore its organic constituents responsible for its phytotherapeutical uses in different ailments.
| References|| |
Satoskar RS, Bhandarkar SD, Rege NN. Pharmacology and Pharmacotherapeutics. 21 st
ed. Mumbai: Popular Prakashan; 2009. p. 143-69.
Mohan H. Text Book of Pathology. 4 th
ed. New Delhi: Jaypee Brothers; 2002. p. 114-60, 432-6.
Percival M. Understanding the Natural Management of Pain and Inflammation. Advanced Nutrition Publications; 1999. Available form: http://www.healingpoints.com/Pain%20and%20Inflammation.PDF. [Last cited on 2013 Oct 27].
Hemadri K. A Treatise on Tribal Medicine. 1 st
ed. Vijayawada: Dr. Koppula Hemadri's House of Tribal Medicine; 2011. p. 53.
Nagabhusan SH, Kotresha K. Wild medicinal plants of Kappat Hills, Gadag District, Karnataka. Res Rev Biomed Biotech 2010;1:111-8.
Saralla RP, Narendran R, Rani VU, Sridharan K, Brindha P. Pharmacognostic standards for diagnosis of Pentatropis capensis
(Asclepiadaceae): A plant Drug used in Indian system of medicine. Int J Pharm Pharm Sci 2012;4:91-6.
Khare CP. Indian Medicinal Plant - An Illustrated Dictionary. New Delhi: Springer (India) Pvt Ltd.; 2007. p. 471.
D'Amour FE, Smith DL. A method for determining loss of pain sensation. J Pharmacol Exp Ther 1941;72:74-9.
Sulaiman MR, Perimal EK, Akhtar MN, Mohamad AS, Khalid MH, Tasrip NA, et al.
Anti-inflammatory effect of zerumbone on acute and chronic inflammation models in mice. Fitoterapia 2010;81:855-8.
Dewey WL, Harris LS, Howes JF, Nuite JA. The effect of various neurohumoral modulators on the activity of morphine and the narcotic antagonists in the tail-flick and phenylquinone tests. J Pharmacol Exp Ther 1970;175:435-42.
George BP, Parimelazhagan T, Saravanan S, Chandran R. Anti-inflammatory, analgesic and antipyretic properties of Rubus niveus
thunb. Root acetone extract. Pharmacologia 2013;4:228-35.
Vinegar R, Schreiber W, Hugo R. Biphasic development of carrageenin edema in rats. J Pharmacol Exp Ther 1969;166:96-103.
Crunkhorn P, Meacock SC. Mediators of the inflammation induced in the rat paw by carrageenin. Br J Pharmacol 1971;42:392-402.
[Table 1], [Table 2]