Anti-Inflammatory and antinociceptive effects of the root extract of capparis Erythrocarpos Isert (Capparaceae)

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Capparis erythrocarpos (Capparaceae) commonly called 'capers' is reputed traditionally in Ghana and other parts of Africa for the management of various inflammatory and pain conditions. The objective of this study was to evaluate the anti-inflammatory, antinociceptive, antipyretic and toxicological properties of the ethanolic root extract using various animal models. Preliminary phytochemical screening showed that the extract contained alkaloids, flavonoids and terpenoids. Acute inflammation was evaluated using carrageenan-induced foot edema in the 7-day-old chick with diclofenac and dexamethasone as reference drugs. Pre treatment with the extract (10-300 mg kg1; p.o.) significantly (F^ioo=3.69, P=0.02), inhibited foot oedema in the chicks with maximal inhibition of 48.86±20.41 %; however, the effect was U-shaped. Diclofenac and dexamethasone dose-dependently inhibited carrageenan-induced foot oedema. Chronic inflammation was evaluated using adjuvant-induced arthritis in rats with dexamethasone and methotrexate as reference drugs. Treatment with the extract (30 mg kg"1; p.o.) significantly (F3,i6=4.25, P=0.02), suppressed adjuvant-induced arthritis with maximal inhibitions of 34.19±15.73 % and also significantly (F3,16=4.28, P-0.02) prevented the spread of arthritis from the ipsilateral to the contralateral paw. Extract (100-300 mg kg"1; p.o.) had weak anti-arthritic effect Results from the prophylactic and combination protocol suggest that C. erythrocarpos (100 mg kg"1; p.o.) therapy alone was not able to significantly ameliorate adjuvant-induced arthritis when administered prophylactically. In contrast amelioration of adjuvant-induced arthritis by combined effect of C. erythrocarpos (100 mg kg1; p.o) and dexamethasone (1 mg kg"1; i.p.); C. erythrocarpos (100 mg kg"1; p.o) and methotrexate (0.3 mg kg"1; i.p.) were established. When combined with dexamethasone, there was a significant inhibition of arthritis in both the acute (P<0.05) and the polyarthritic (P<0.001) phases. In combination with methotrexate, there was no significant effect in the acute phase (P>0.05) but significant inhibition (P<0.05) occurred in the polyarthritic phase. Antinociceptive effect of G erythrocarpos extract (10-300 mg kg"1; p.o.) was evaluated using the formalin-induced pain model with morphine (1-10 mg kg"1; i.p.) as reference drug. The effects following naloxone and theophyline pretreatment were also studied. The results showed that the extract dose- dependently inhibited both phases of formalin-induced pain. The extract (100 mg kg significantly reduced formalin-induced nociception with a percentage inhibition of 47.54±5.65 % (F3/16 =15.25; P< 0.0001) in the first phase and 80.01±3.77 % (F3/i6= 35.34; P < 0.0001) in the second phase. Naloxone did not reverse the antinociceptive effect of the extract in both the neurogenic phase 43.44±4.15 % and the inflammatory phase 82.41±0.90 %; however, theophyline significantly and completely reversed the first phase and significantly but partially reversed the second phase with percentage inhibition of 57.08±1.88 %. C. erythrocarpos (30-300 mg kg"1; p.o.) dose-dependently decreased baker's yeast induced fever. Paracetamol (10-100 mg kg"1; p.o.) was used as the reference drug. In the toxicity study, using high concentrations of the extract (0.3-3 g kg"1 p.o.) there were no significant differences found in most of the haematological indices, serum biochemical parameters and organ/body weight ratios hence the extract has a high safety profile. In summary, G erythrocarpos has anti-inflammatory, antinociceptive and anti pyretic activity and these findings support the use of the extract in traditional medicine.  
A thesis submitted to the College of Health Sciences in fulfilment of the requirements for the degree of Master of Philosophy, 2008