Study on antipyretic activity of Rumex vesicarius leaves extract in albino rabbits

Aim: The present study was planned to investigate the possible antipyretic activity of methanolic leaves extract of Rumex vesicarius against various protocols of experimentally induced pyrexia in rabbits. Materials and Methods: Ninety healthy adult albino rabbits were divided into three groups (A, B, C), 30 rabbits in each group. Pyrexia was induced by three different protocols, i.e. boiled milk (0.5 ml/kg body weight, intra-peritonealy), Brewer's yeast (10 ml/kg, subcutenously) and D-amphetamine (5 mg/kg, i.p.), to the groups A, B and C respectively. Each group was further subdivided into five sub groups (1, 2, 3, 4 and 5) each having 6 animals. Sub group-1 served as positive control group; sub group-2 was treated with aspirin (10 mg/kg, orally) standard antipyretic agent; sub group-3, 4 and 5 were treated orally with methanolic leaves extract of Rumex vesicarius at dose rate of 80, 120 and 160 mg/kg body weight respectively. The hypothermic effect was observed at different time intervals in each protocol. Results: Rumex vesicarius L. significantly (p<0.05) lowered the elevated temperature in all scenarios. Maximum antipyretic effect was observed at 3h of post induction pyrexia in group A and at 4h after pyrexia in the groups B and C. Moreover, the antipyretic effect was concentration dependent and comparable to the standard aspirin at higher doses. Conclusion: The leaves of Rumex vesicarius have the antipyretic action in dose dependent manner, based upon this scientific validation, the claims of the local communities are true. The exact mode of action of this plant is still not clear, however, a single or a number of bioactive compounds of the plant may be responsible for its antipyretic activity.


Introduction
temperature [6].Antipyretic drugs usually inhibit COX-2 expression to decrease the elevated body Over the centuries, medicinal plants served as a temperature by inhibiting PgE2 biosynthesis [7].These tremendous remedy for a variety of ailments in synthetic agents irreversibly inhibit COX-2 with high mankind worldwide [1].Primarily, these plants are selectivity but toxic to cardiac muscles, hepatic cells, used as a vital source of health care system [2].In glomeruli, and cortex of brain.On the other hand, Pakistan, this trend is well-known in the name of natural COX-2 inhibitors have lower selectivity with Hikmat/Tabib.Approximately 600-1000 medicinal few side effects [7].Search for herbal remedies with plants of the country are being utilized by more than potent antipyretic activity received momentum recently 40,000 registered and unregistered Hakims or Tabib as the available antipyretics, such as paracetamol, [3].This practice is derived from experiences, without nimusulide etc. have toxic effects on the various organs any scientific evidence; thus a proper validation of of the body.scientific grounds is necessary [4].
Rumex vesicarius L. is an annual plant belong to Pyrexia or fever occurred as a result of secondary family Polygonaceae, commonly known as "Bladder impact of infection, malignancy or other diseased dock" and locally as "Khat palak the known antipyretic agent aspirin at dose rate of (10 FPST215) was deposited.The leaves were air-dried mg/kg orally) and served as negative control group.and ground into powder.
Sub-groups 3, 4 and 5 received methanolic extract of R. vesicarius orally at dose rate of 80 mg, 120 mg and 160 Preparation of crude extract: The powdered plant mg/kg respectively.Finally, rectal temperatures were material (1 kg) was subjected to maceration in 70% recorded at 1 h intervals up to 3 h.methanol in amber colored glass bottle at room temperature for 8 days with occasional shaking [12].
b. Yeast-induced pyrexia: Each rabbit of group-B was The solution was filtered through muslin cloth and administered subcutaneously with 20% W/V aqueous Whattma-1 filter paper to remove any undesirable suspension of yeast at a volume of 10 ml/kg [18], material.The filtrate was evaporated on a rotary animals with elevated temperatures upto 1ºC were evaporator (Rotavapor, BUCHI labrotechnik AG, preferred for the study.The arrangements of rabbits of Model 9230, Switzerland) at 37ºC under reduced group-B into sub-groups were similar to the group-A.pressure and the extract was stored at -4°C in air tight The extract understudy was administered orally after jars in lab refrigerator.
the pyrogen at the dose of 80 mg/kg, 120 mg/kg, and 160 mg/kg to respective groups of rabbits.The control Chemical reagents: D-amphetamine (BSA conjugant, group received distilled water (10ml/kg) whereas Shanghai Jieyi Biotechnology Co., Ltd.), Brewer's aspirin was administered to the reference group.The yeast (Jinan Shuangmai Beer Materials Co., Ltd.) were rectal temperature of the groups were recorded at 1h procured from local market and 20% W/V suspension interval for 5h. of yeast was prepared.Aspirin as Disprin soluble tablet was purchased from a local market of Reckitt Benckiser c. D-amphetamine induced pyrexia: Amphetamine (5 (Paksitan) Ltd and used as an antipyretic agent.The mg/kg, i.p.) was administered to the rabbits of group-C standard solution was prepared by dissolving the tablet after obtaining basal temperatures.Hyperthermia in the solvent to obtain 15 mg aspirin per 2 ml solution.developed 0.5 h following administration.Rabbits The dose of aspirin was maintained at 10 mg/kg body were placed into sub-groups on similar pattern as weight [13].
group-A and B. The extract (80, 120 and 160 mg/kg, orally), aspirin (10 mg/kg orally) were administered to Animals: The experiment was carried out on albino the animals at peak hyperthermia.Rectal temperature rabbits of both sexes, 13-15 months old, weighing was obtained at 1 h interval for 5 h [18].between 1.5 and 1. mg/kg i.e. 71% while the antipyretic effect of aspirin A level of significance was based on the 95% level of was 88% after 3h of induction of hyperthermia.probability.The results were expressed as mean ± Effect on yeast-induced pyrexia: The results revealed standard error (SEM).
the antipyretic effects in a dose dependent manner, at

Results
all test doses (80, 120 and 160 mg/kg orally) as shown in Table -3.The percent pyrexia inhibition is presented Phytochemical screening: The phytochemical screein Figure -2.Maximum antipyretic effect (74%) was ning of the methanolic extract of the whole plant of observed at 160 mg/kg dose of RvCr after 4h of Rumex vesicarius revealed the presence of saponins, induction of pyrexia.The antipyretic activity of aspirin tannins, anthraquinones, coumarins, phenols and (77.14%) was greater than that of the highest dose of flavanoid (Table-1). RvCr.

Acute toxicity: In acute toxicity study, RvCr was found
Effect on amphetamine-induced pyrexia : The results safe at all test doses and no mortality was observed to a revealed the antipyretic activity of all the test doses (80, dose as high as 500 mg/kg.120 and 160 mg/kg orally) of RvCr as shown in  Yeast has a different mechanism of action and served as reduction in amphetamine-induced hyperthermia.The a model for pathogenic fever.Yeast stimulates the maximum antipyretic effect (78%) was exhibited at release of inflammatory mediators like cytokines -ILth 1, IL-6, TNF etc., leading to hyperthermia.Prostaglandins dose of 160mg/kg of RvCr on 4 hr post induction of E2 produced by cyclooxygenase (COX-2) is regarded pyrexia.The antipyretic effect of aspirin (80%) was as an imperative downstream mediator of fever within lowered than the highest dose of RvCr.

Discussion
inflammatory drugs evoke their antipyretic action through The acute toxicity study result showed that this the inhibition of prostaglandin synthetase within the plant might be considered a broad nontoxic one.Our hypothalamus.The antipyretic action is possibly due to experimental results revealed that all the three different a decrease in the brain concentration of prostaglandin doses (80, 120 and 160 mg/kg) of Rumex vesicarius L.
E2 especially in the hypothalamus through its action on possess a significant antipyretic effect in maintaining COX-2 or by enhancement of the production of the normal body temperature and reduce all the three body's own antipyretic substances like vasopressin and different protocols of elevated rectal temperature in arginine [20].The other possible mechanism is that the rabbits.Moreover, the antipyretic action of the plant is extract could have mediated the dilation of superficial comparable to that of the standard antipyretic drug, blood vessels which in turn leads to improved dissipation aspirin.Such reduction of rectal temperature of the of heat following resetting of hypothalamic temperature tested animals by the various doses of RvCr is possibly control center [21].This action may be account of because of the presence of a single bioactive substance phytochemical compounds present in the plant.Thereor a mixture of compounds in them.
fore, the hypothermic activity of the extract may not be In this study, the methanolic extract of Rumex disparate with the inhibition of one or combination of vesicarius was found to inhibit drastically (P<0.05) the mechanisms mentioned above.the boiled milk, D-amphetamine and yeast induced Conclusion pyrexia in dose dependant manner.These all compounds The methanolic extract of Rumex vesicarius was have different mechanism of action to induce pyrexia.
proved as a natural safe remedy for the treatment of Amphetamine triggers the release of biogenic amines pyrexia in albino rabbit.Our current findings thus from their storage sites in nerve terminals resulting in support the claims of traditional medicine practitioners high level of cAMP in brain.This leads to the synthesis as an antipyretic agent.It is also evident from the study of prostaglandins from arachidonic acids produced in that Rumex vesicarius exhibited dose dependent neurons by receptor-mediated hydrolysis of phospho- 6 kg [14] at the laboratory of Al-Manara College of Pharmacy, Multan.Animals were Determination of percent pyrexia inhibition: The percent pyrexia inhibition was calculated by the Effect on boiled milk-induced pyrexia: The resultant following formula: effects of various doses of Rumex vesicarius leaves on boiled milk induced pyrexia in rabbits are depicted in Percentage reduction = B-Cn/ B-A X 100 Table-2.The RvCr markedly (P < 0.05) attenuated Where n = 1,2,3,4 and 5 hyperthermia induced by boiled milk.The percent Statistical analysis: Data generated in the present pyrexia inhibition was dose dependent and remained study were subjected to statistical analysis by significant up to 3h of administration (Figure-1).The paired student's t -test for calculation and comparison maximum antipyretic effect was observed at 160 of mean values between the groups at various intervals.

on antipyretic activity of Rumex vesicarius leaves extract in albino rabbits asthma
, bronchitis, scabies, leucoderma, toothache and purchased from the local market of Multan.Prior to the hepatic diseases[8].The leaves are applied externally experiment, the rabbits were kept in iron cages[15]to to burns while the seeds are tonic, remove pain from the become accustomed to the environment, and fed with back and the lumber region and aphrodisiac[9].The protocol of the study was Pyrexia was induced by following three different approved by the College Ethical Committee (ECE) protocols to these groups.according to the guidelines provided by the ECE for the Garh.The folk use of this plant is laxative, appetizer, prostaglandin E2 (PgE2) near hypothalamic area and diuretic, analgesic, purgative, stomachic, astringent, thereby trigerring the hypothalamus to elevate the body antispasmodic and antibacterial [8].In addition, it has been used in the treatment of tumors, piles, calcules, bad digestion, nausea, dyspepsia, flatulence, constipation, heart troubles, pains, diseases of the spleen, hiccough, Study a. Milk-induced pyrexia: Milk was collected from local Control and Supervision of Experiments on Animals cattle.Rabbits of group-A were injected with boiled (CSEA).milk intra-peritonealy at room temperature at the dose Plant material: Leaves of the plant were collected from of 0.5 ml/kg body weight to induce pyrexia.Fever various part of Mondka Shahlamal District Muzaffar occurred about 1 to 2 h post administration [13, 17].Garh, Pakitan with the help of a local herbalist and Rabbits were divided into five sub-groups (1 to 5), 6 identified by Prof. Dr. Altaf Dasti, Institute of Pure and rabbits in each sub-group.Sub-group-1 served as Applied Biology, Bahauddin Zakariya University, positive control group whereas sub-group-2 received Multan, Pakistan, where its voucher specimen (No.

Table - 1
. Phytochemical screening of methanolic extract of whole plant of Rumex vesicarius

Table - 4
. The percent pyrexia inhibition is presented in lipids that ultimately results in hyperthermia[19].Figure-3.There was a progressive dose-dependent

Table - 2
. Effect of methanolic extract of Rumex vesicarius leaves on boiled milk-induced pyrexia in rabbits Effect of methanolic extract of Rumex vesicarius leaves on yeast induced-pyrexia in rabbits

Table - 4
. Effect of methanolic extract of Rumex vesicarius leaves on yeast induced-pyrexia in rabbits