A COMPARATIVE STUDY OF ANTI-NOCICEPTIVE ACTIVITY OF CURCUMA LONGA LINN. WITH THAT OF IBUPROFEN IN EXPERIMENTAL ANIMALS

Objective: The aim of the study is to evaluate and compare the analgesic activities of Curcuma longa Linn. in the experimental animals. 
Methods: The present study was conducted in the Department of Pharmacology, Gauhati Medical College and Hospital, after getting approval from the Institutional Animal Ethics Committee (No MC/68F/2009/MAR-19/02). Healthy rodents weighing between 150 and 200 g were selected and randomly divided into five groups, each group consisting of six animals. Tail-flick analgesiometer was used to assess the analgesic activity of C. longa Linn. and ibuprofen in the experimental animals. Appropriate statistical analyses like Student’s t-test were used to analyze the data. 
Results: The mean reaction time (s) was prolonged on gradually increasing the dose of C. longa Linn. from 200 to 400 mg/kg. At 400 mg/kg dose C. longa Linn. produced similar analgesic activity as compared to ibuprofen (30 mg/kg). 
Conclusion: From the study, it can be concluded that curcumin has the capacity to attenuate pain, and when administered in high doses, may produce similar activity as other conventional NSAID’s.


INTRODUCTION
Curcumin is the active ingredient of turmeric. It belongs to the family Zingiberacea. Curcumin has been extensively used in Ayurveda and traditional Indian System of Medicine since a very long time. It has been observed that curcumin has a lot of benefits on a person's health, as discussed by Sodhi et al. [1]. It can act as an anti-inflammatory, as shown by Arora et al. [2], antibacterial, antipyretic, antioxidant, and analgesic agent.
Studies done by Chandra et al. [3] and Deodhar et al. [4] showed that curcumin was effective in arthritis. It is also used in the treatment of fever, Alzheimer's disease, skin conditions like acne, eczema, inflammatory bowel disease, heart diseases.
Other studies done by Bose et al. [5] and Mehta et al. [6] also highlighted the beneficial activity of curcumin in the treatment of different types of cancer.
A few studies like that done by Jagetia et al. [7] have shown that turmeric when taken in the diet on a regular basis has helped to boost the immune system of an individual.
Due to the excellent health benefits of turmeric, a lot of turmeric supplements have flooded the market.
Ibuprofen is a type of NSAID. They work by inhibiting the production of inflammatory mediators like prostaglandin which is responsible for causing pain, inflammation, and fever. Cooper et al. [8] studied the analgesic activity of ibuprofen. Ibuprofen and other NSAID's are associated with a lot of side effects, including gastric ulcer and interstitial nephritis on prolonged use.
The purpose of the study is to evaluate whether curcumin present in turmeric has got significant analgesic activity and can be used as an alternative to the conventional NSAID's in the treatment of painful conditions.

METHODS
The study was conducted in the Department of Pharmacology, Gauhati Medical College and Hospital after obtaining approval from the Institutional Animal Ethics Committee (No MC/68F/2009/ MAR-19/02).
Thirty healthy Wistar rats weighing between 150 and 200 g of either gender were selected and allocated in five groups. Each group comprised of six animals.
They were maintained on a pellet diet and water was givenad libitum. The animals were acclimatized for 1 week before the experiment. The duration of the study was 21 days.

Phukan and Das
The study revealed that the mean reaction time at the end of 60 min was increased in Groups 2, 3, 4, and 5.
Group 2 (ibuprofen 30 mg/kg) showed the highest increase in mean reaction time (11.4 ± 0.18 s). It was also observed that with the gradual increase in the dosage of curcumin, the mean reaction time also increased gradually.
Group 5 (curcumin 400 mg/kg) produced nearly similar analgesic activity (mean reaction time −10.4 ± 0.15 s) as compared to Group 2 (ibuprofen 30 mg/kg) whose mean reaction time was 11.4 ± 0.18 s at the end of 60 min.
Other studies conducted by Ojewole et al. [11] and Hajare et al. [12] also revealed the analgesic activity of some other plant compounds such as Zingiber officinale and Dalbergia sissoo leaves similar to the analgesic activity exhibited by curcumin present in turmeric.
Other than analgesic activity, curcumin also possesses anti-inflammatory activity which has been demonstrated by Sulthana et al. [13] on osteoarthritis patients.
Curcumin along with azadirachta indica was also shown to exhibit antifungal activity by Saini et al. [14].

CONCLUSION
From the study, we can conclude that curcumin has got significant analgesic activity with a gradual increase in its dose.
The anti-nociceptive activity of curcumin can be utilized to treat a lot of chronic pain conditions such as arthritis, cancer, diabetes, and multiple sclerosis and thereby minimize the use of NSAID's which can have a negative impact on the health on prolonged use.
One major drawback of curcumin is that it has very poor oral bioavailability when given through oral route which can be effectively countered by giving curcumin with piperine or nanocurcumin formulations.

ACKNOWLEDGMENT
The author is thankful to the Professor and HOD, Department of Pharmacology, for providing laboratory facilities to conduct the study.

AUTHORS' CONTRIBUTION
All the authors contributed to the preparation of the final manuscript.

CONFLICTS OF INTEREST
None declared.

FINANCIAL SUPPORT AND SPONSORSHIP
Nil.

Data analyses
Descriptive statistics and inferential statistics such as Students t-test and GraphPad were used to evaluate the data findings. P = 0.05 was fixed as the level of significance.

RESULTS
In the present study, the mean reaction time (s) was noted down before the beginning of the experiment (at 0 min) and again at the end of 60 min after administering the drugs (Table 1 and Fig. 1).

DISCUSSION
The C. longa Linn. crude extract was given in increasing doses of 100, 200, and 400 mg/kg doses, respectively, to Groups 3, 4, and 5 for 21 days.
Groups 1 and 2 were administered N/S and ibuprofen.
By the tail-flick analgesiometer method, the mean reaction time in seconds was noted down before the administration of the drugs and once again after the administration of the drugs at the end of 60 min.