Protective Effect of High Molecular Weight Protein Sub-fraction of Calotropis procera Latex in Monoarthritic Rats.
BACKGROUND
Proteins present in the latex of Calotropis procera have been shown to produce anti-inflammatory effect and to afford protection in various disease models.


OBJECTIVE
To determine the efficacy of high molecular weight protein sub-fraction (LPPI) of latex of C. procera in ameliorating joint inflammation and hyperalgesia in a preclinical model of arthritis.


METHODS
Monoarthritis was induced in rats by intra-articular injection of Freund's complete adjuvant (FCA) and the effect of two doses of LPPI (5 and 25 mg/kg) and diclofenac (5 mg/kg) was evaluated on joint swelling, stair climbing ability, motility, and dorsal flexion pain on day 3. The rats were sacrificed on day 3 to measure tissue levels of reduced glutathione (GSH) and thiobarbituric acid reactive substances (TBARS). Evaluation of joint histology was also made.


RESULTS
Intra-articular injection of FCA produced joint swelling and difficulty in stair climbing ability, motility, and pain on flexion of the joint as revealed by scores obtained for these functional parameters. LPPI produced a dose-dependent decrease in joint swelling and improved joint functions. Arthritic rats also revealed altered oxidative homeostasis where joint tissue GSH levels were decreased and TBARS levels were increased as compared to normal rats. The levels of these oxidative stress markers were near normal in arthritic rats treated with LPPI. Moreover, treatment with LPPI also maintained the structural integrity of the joint. The protective effect of LPPI was comparable to the standard anti-inflammatory drug, diclofenac.


CONCLUSIONS
The findings of the present study show that LPPI fraction comprising high molecular weight proteins could be used for the alleviation of arthritic symptoms.


CONCLUSIONS
High molecular weight protein sub-fraction of latex of Calotropis procera (LPPI) reduced joint swelling and hyperalgesia in arthritic ratsLPPI produced a significant improvement in stair climbing ability and motility in arthritic ratsLPPI normalized the levels of oxidative stress markers in the arthritic jointsTreatment with LPPI reduced neutrophil influx and edema in the arthritic joints Abbreviations used: FCA: Freund's complete adjuvant, GSH: Glutathione, TBARS: Thiobarbituric acid reactive substances, TBA: Thiobarbituric acid, MDA: Malondialdehyde, LPPI: Latex protein fraction PI.
Department of Plant Molecular Biology, Delhi University South Campus, Benito Juarez Road, Dhaula Kuan, New Delhi, India; Department of Pharmacology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
Priyanka
P
Chaudhary
Department of Biochemistry and Molecular Biology, Federal University of Ceará, 60451-970 Fortaleza, CE, Brazil.
Marcio V
MV
Ramos
Federal Institute of Education of Ceará State, Baturité-Ce CEP 62760-000, Brazil.
Mirele da Silveira
Mda S
Vasconcelos
Department of Pharmacology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
Vijay L
VL
Kumar
Arthritis; hyperalgesia; inflammation; latex proteins; oxidative stress