Diclocor is superior to diclofenac sodium and quercetin in normalizing biochemical parameters in rats with collagen-induced osteoarthritis

Quercetin decreases the antinociceptive effect of diclofenac in an arthritic gout-pain model in rats

OBJECTIVE

To analyse the antinociceptive interaction between quercetin (QUER) and diclofenac (DIC) in experimental arthritic gout-pain.

METHODS

The antinociceptive effect of DIC and QUER alone and in combination were evaluated using an arthritic gout-pain model. Pain was induced through intra-articular administration of uric acid in the rats and the treatments were administered 2 h later. Additionally, the cyclooxygenase (COX) activity was determined in rats treated with DIC, QUER and their combination.

KEY FINDINGS

DIC induced a maximal effect of 69.7 ± 2.7% with 3.1 mg/kg; whereas QUER only produced 17.6 ± 2.6% with the maximal dose (316 mg/kg). Ten of twelve DIC + QUER combinations showed a lesser antinociceptive effect than DIC alone did (P < 0.05). Moreover, DIC reduced total-COX (70.4 ± 1.3 versus 52.4 ± 1.8 and 77.4 ± 9.0 versus 56.1 ± 1.3, P < 0.05) and COX-2 (60.1 ± 1.0 versus 42.4 ± 1.8 and 58.1 ± 2.4 versus 48.7 ± 1.3, P < 0.05) activity after 1 and 3 h, respectively. Nevertheless, only the COX-2 activity induced by DIC was prevented in the presence of QUER (63.2 ± 3.0 versus 60.1 ± 1.0 and 56.6 ± 1.3 versus 58.1 ± 2.4 at 1 and 3 h, respectively).

CONCLUSIONS

All these data demonstrated that the simultaneous administration of QUER + DIC produces an unfavorable interaction on the antinociceptive effect of DIC. Therefore, this combination might not be recommendable to relieve arthritic gout-pain.

Anti-inflammatory and analgesic potential of OA-DHZ; a novel semisynthetic derivative of dehydrozingerone

Despite various advances in the arena of the current system of medicine, there are numerous side effects associated with the therapeutics which essentially demand research on the development of safer therapeutics. One way is to explore the bioactive plant secondary metabolites and their semisynthetic derivatives. In context to this, we analyzed OA-DHZ, a dehydrozingerone derivative as the later has been reported to show anti-inflammatory and analgesic properties. OA-DHZ was found to be having promising anti-inflammatory and analgesic potential. OA-DHZ was found to inhibit the carrageenan-induced edema and leukocyte migration, acetic acid-induced increase in vascular permeability and lipopolysaccharide-induced pro-inflammatory cytokines like TNF-α, IL-6, and IL-1β. Meanwhile, it was also found to potentially inhibit thermally as well as chemically induced pain signifying its analgesic/nociceptive potential. Further, safety pharmacology studies using in vivo animal models for the central nervous system, gastrointestinal tract, the cardio-respiratory system suggest that optimum functioning of vital organ systems does not get altered after single oral administration. Also, the acute toxicity study revealed its nontoxic nature up to 2000 mg/kg. This study paves the way for future exploration and development of OA-DHZ based on its potent activity and nontoxic nature.