Background: In the present study, methanolic extract of Boswellia serrata was assessed for anti-arthritic action using Frund’s complete adjuvant (FCA) induced arthritis in rats.
Material and methods: B. serrata (100mg/kg and 200 mg/kg p.o) was evaluated for anti-arthritic activity using Frund’s complete adjuvant (FCA) induced arthritis in rats. B. serrata extracts at dose of 100mg/kg and 200 mg/kg p.o. was administered for 21 days after the injection of FCA in rats. The parameters like alkaline phosphatase, acid phospatase, erythrocyte sedimentation rate and total WBC count was observed which the major markers of arthritis.
Results: Significant inhibition (P < 0.01) ofpaw edema volume was observed from day 5th to 21st in the groups treated with B. serrata. Significant increase in all the markers wasfound in the rats treated by FCA. At dose of 100mg/kg and 200 mg/kg B. serrata display noticeable decrease in all markers. A better activity of Boswellia serratawas found at 200 mg/kgdose against FCA induced arthritis in rats.
Conclusion: Present study indicates that Boswelli aserrata has significant anti-arthritic activity against FCA induced arthritis in rats.

Keywords: Boswellia serrata, Frund’s complete adjuvant(FCA), prednisolone.

INTRODUCTION

Arthritis is a chronic, progressive, systemic inflammatory autoimmune disorder affecting the synovial joints and typically producing symmetrical arthritis that leads to joint destruction, which is accountable for the defect and impairment. The significant morbidity and mortality has a substantial impact (Buch and Emery 2002). Prevalence of arthritis in Indian subcontinent is 1.5-2%. The epidemiological proportion of arthritis in female and male is 3:1 and the prevalence is 1%. FCA encouraged arthritis in rats is a chronic inflammatory disease characterized by infiltration of synovial membrane in association with destruction of joints resembles RA in humans (Katz and Piliero, 1969).
B. serrata possess antioxidant, anti-inflammatory, anticancer and anti-allergic potential (Akaishi et al., 2008; Ke et al., 2008; Sriram and Subramanian, 2010). It not only prevents effectively lysosomal enzyme secretion but also release of arachidonic acid in neutrophils of rats (Tordera al., 1994). More, B. serratas tops mammalian 5-lipoxygenase and cyclooxygenase enzymes (Laughton et al., 1991).
B. serrata contains boswellic acids which play as a vital role for treatment of various anti-inflammatory disorders. Boswellia extract is thought as an alternate to NSAID due to fewer side effects.
The present study has been carried out to evaluate the antiarthritic activity of methanolic extract of B. Serrata on the Freund’s adjuvant induced arthritis in rats.

MATERIALS AND METHODS

Animals
Male albino rats of Wistar strain weighing 160-180 g were purchased from National Institute of Biosciences, Pune and kept in quarantine for one week in housed at the institute animal house in groups of six animals per cage at standard laboratory conditions at a temperature of 240C±10C, humidity of 45–55% and 12:12 hours dark and light cycle. The experiments were performed between 10:00 a.m. to 5:00 p.m. Animals had access to food and water ad libitum. Experimental protocols were approved by the Institutional Animal Ethics Committee. Animals were kept in testing laboratory 1 hr before the experimentation for adaptation purpose. The investigation was done in noise free space.

Acute oral toxicity study
Acute toxicity test were performed on rat of either sex weighing160-180 g body weight as per the OECD guidelines 423. Changes in behavioral, toxicity and motility of animals were observed for 48 hrs. Extract has exhibited no mortality in animals up to 3000 mg/kg dose. Therefore 100 mg/kg and 200 mg/kg dose were selected as the therapeutic dose.

Complete Freund’s adjuvant induced arthritis
Arthritis was induced by a single intra-dermal dose (0.1 ml) of Freund’s Complete adjuvant (FCA) comprising 1.0 mg dry heat-killed Mycobacterium tuberculosis per milliliter sterile paraffin oil into a foot pad of the left hind paw of rats.13 A glass syringe (1 ml) with the locking hubs and a 26G needle was used for injection. Animals were anesthetized with ether inhalation prior to and during adjuvant injection. The swelling of paws of animals were examined from time to time (up to 21 days) in each paw from the ankle using Digital Plethysmometer (Winter CA et al., 1962).

Experimental set up
Animals were divided in five groups as follows:
Group I: Control group.
Group II: FCA induced arthritic group.
Group III: FCA with prednisolone (10 mg/kg).
Group IV: FCA with extract of B. serrata (100 mg/kg).
Group V: FCA with extract of B. serrata (200 mg/kg).

Statistical analysis
Data were expressed as mean ± standard error mean (S.E.M.). Data was analyzed by one way analysis of variance (ANOVA) followed by Dunnett’s. P < 0.05 and 0.01 were considered to indicate statistical significance.

RESULTS

Paw volume
Fig.1 shows change in paw volume measurement after the administration of prednisolone 10 mg/kg and B. serrata 100 and 200 mg/kg. Whereas for more than 20 days gradually the adjuvant injected paw turns out to be swollen. The alteration in paw volume might be separated in two stages. In first stage, edema rate of the injected foot pad increase and reached a peak during first 5-10 days. Thereafter, swelling gradually decreased until 15th day when the paw began to swell again and picked in the 3rd week (second stage). After the adjuvant injection, Prednisolone and B. serrata shown significantly (P < 0.01) suppress the secondary increase in swelling of injected foot in all groups as compare to arthritic control (Group II). The Group V (B. serrata 200 mg/kg) produced a better suppression of paw volume as compared to 100 mg/kg (Fig.1).

Bio-marker estimation
A marked increase in the activity of biological marker enzymes ALP and ACP were observed in the serum of arthritis rats (Group II). Rats treated with prednisolone (10 mg/kg) and B. serrata (100 and 200 mg/kg) displayed a significant (P < 0.01) reduction in membrane marker enzyme activity (Figure 2).

Figure 1. Change in paw edema in control and experimental rat . Click here to view full image

Bio-marker estimation
A marked increase in the activity of biological marker enzymes ALP and ACP were observed in the serum of arthritis rats (Group II). Rats treated with prednisolone (10 mg/kg) and B. serrata (100 and 200 mg/kg) displayed a significant (P < 0.01) reduction in membrane marker enzyme activity (Fig. 2).

Figure 2. Effect of B. serrata in membrane marker enzymes of control and treated rats. Click here to view full image

Figure 3. WBC count and erythrocyte sedimentation rate of control and treated rats. Click here to view full image

DISCUSSION

Adjuvant induced arthritis inhibition in rats is one of the most suitable test procedures to screen anti-arthritic agents since it closely resembles human arthritis reported by most of the investigators.
Reduction of paw swelling by B. serrata at dose of100 and 200 mg/kg body weight treated rats from the second week onwards (Fig.1 and 2) might be owed to immunological defense and controlling migration of WBC (Olsen I et al., 1990).
In the present study, the activity of lysosomal enzymes in plasma was markedly increased in the adjuvant induced arthritic rats and significantly (P < 0.01) reduced after treatment with B. serrata at dose of 100 and 200 mg/kg body weight (Fig. 2). An essential mechanism of antiarthritic activity is the membrane stability modulating effect (Subrata et al., 1994).
It was found that the administration of B. serrata (100 and 200 mg/kg body weight) leads to inhibition of leukocyte migration which may have beneficial effect for joint preservation.
Erythrocyte sedimentation rate (ESR) in the FCA treated group several fold high compared to drug treated groups (Fig. 3).

CONCLUSION

Present study indicates that Boswellia serrata has significant anti-arthritic activity against FCA induced arthritis in rats.

ACKNOLEDGEMENT

We are grateful to Principal, Allana College of Pharmacy, Pune for providing necessary facilities for research work.

CONFLICT OF INTEREST
None declared.

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