Quercetin Reduces Antinociceptive but Not the Anti-Inflammatory Effects of Indomethacin, Ketorolac, and Celecoxib in Rats with Gout-like Pain

Abstract

The objective of this study was to determine the pharmacological interaction of some common NSAIDs in the presence of quercetin (QUER). Indomethacin (IND), ketorolac (KET), or celecoxib (CEL) were assessed alone and in combination with QUER using experimental gout-arthritic pain and the carrageenan-induced edema test in rats to evaluate their antinociceptive and anti-inflammatory effects, respectively. The antinociceptive effect of each NSAID was also analyzed after the repeated administration of QUER for 10 days. Molecular docking analysis on COX-1/COX-2 with each drug was explored to analyze the pharmacological interaction. QUER produced minimal antinociceptive or anti-inflammatory effects on experimental gout-arthritic pain or on the carrageenan-induced edema in rats. Additionally, QUER reduced the antinociceptive effect of NSAIDs, mainly those COX-1 inhibitors (IND and KET), when they were combined. However, QUER did not modify the anti-inflammatory effect of these COX-1 inhibitors and slightly improved the anti-inflammatory effect of the COX-2 inhibitor (CEL). According to the docking analysis, COX-1 and COX-2 are likely implicated in these pharmacological interactions. In conclusion, QUER, a known bioactive natural product, may alter the antinociceptive efficacy of NSAIDs commonly used to relieve gout-like pain and suggests not using them together to prevent a negative therapeutic interaction in this effect.

Keywords: NSAIDs; gout pain; infra-additive interaction; natural products; quercetin.

Figure 1

Chemical structures of some non-steroidal anti-inflammatory drugs (NSAIDs), suchas indomethacin (IND), ketorolac (KET), and celecoxib (CEL), as well as quercetin (QUER), a flavonoid.

Figure 2

(A) Dose-response curves (DRCs) of the antinociceptive effect of quercetin (QUER, 31.6–316 mg/kg, ip), indomethacin (IND, 1–10 mg/kg, po), ketorolac (KET, 0.31–10 mg/kg, po), and celecoxib (CEL, 1.0–31.6 mg/kg, po) in individual administration. Each point represents the mean ± S.E.M. of six animals. * p < 0.05 vs. VEH group. (B) Antinociceptive effect induced by IND (1–10 mg/kg) in the absence and the presence of 31.6 mg/kg QUER (COMB-1) or 100 mg/kg QUER (COMB-2). (C) Antinociceptive effect induced by KET (0.31–10 mg/kg) in the absence and the presence of 31.6 mg/kg QUER (COMB-3) or 100 mg/kg QUER (COMB-4). (D) Antinociceptive effect induced by CEL (0.31–31.6 mg/kg) in the absence and the presence of 31.6 mg/kg QUER (COMB-5) or 100 mg/kg QUER (COMB-6). Each point represents the mean ± S.E.M. of the six animals per group. In this analysis, the effect of the individual administration of QUER was not considered. * p < 0.05 vs. effect induced by the corresponding NSAIDs in individual administration, two-way ANOVA followed by Tukey’s test.

Figure 3

(A–C) Three-dimensional graphics from the analysis of the interaction of the antinociceptive effect of the combination of indomethacin (IND) with QUER. (A) Doses of IND (Y-axis) and QUER (X-axis) and their antinociceptive effects in individual administration or in combination (Z-axis). (B) Subtraction of the antinociceptive effect of each combination minus the individual effect of IND and QUER. (C) Surface of synergistic interaction of the antinociceptive effect of indomethacin (IND) with QUER. The red circle indicates the combination that induced the maximum antinociceptive interaction (MAI) of this combination. (D,E) Two-dimensional graphics showing the individual effects of IND and QUER at 31.6 mg/kg (D) or 100 mg/kg (E). In both, the first bar shows the antinociceptive effect of IND and QUER in individual administration and represents the sum of the individual effects of the drugs (expected effect), while the second bar (with a white background) represents the antinociceptive effect obtained experimentally with the respective combination. * p < 0.05 vs. expected effect (addition of the antinociceptive effect of IND and QUER in individual administration). Two-way ANOVA followed by Tukey’s test.

Figure 4

(A–C) Three-dimensional graphics from the analysis of the interaction of the antinociceptive effect of the combination of ketorolac (KET) with QUER. (A) Doses of KET (Y-axis) and QUER (X-axis) and their antinociceptive effects in individual administration or in combination (Z-axis). (B) Subtraction of the antinociceptive effect of each combination minus the individual effect of KET and QUER. (C) Surface of synergistic interaction of the antinociceptive effect of ketorolac (KET) with QUER. The red circle indicates the combination that induced the maximum antinociceptive interaction (MAI) of this combination. (D,E) Two-dimensional graphics showing the individual effects of KET and QUER at 31.6 mg/kg (D) or 100 mg/kg (E). In both, the first bar shows the antinociceptive effect of KET and QUER in individual administration and represents the sum of the individual effects of the drugs (expected effect), while the second bar (with a white background) represents the antinociceptive effect obtained experimentally with the respective combination. * p < 0.05 vs. expected effect (addition of the antinociceptive effect of KET and QUER in individual administration). Two-way ANOVA followed by Tukey’s test.

Figure 5

(A–C) Three-dimensional graphics from the analysis of the interaction of the antinociceptive effect of the combination of celecoxib (CEL) with QUER. (A) Doses of CEL (Y-axis) and QUER (X-axis) and their antinociceptive effects in individual administration or in combination (Z-axis). (B) Subtraction of the antinociceptive effect of each combination minus the individual effect of CEL and QUER. (C) Surface of synergistic interaction of the antinociceptive effect of celecoxib (CEL) with QUER. The red circle indicates the combination that induced the maximum antinociceptive interaction (MAI) of this combination. (D,E) Two-dimensional graphics showing the individual effects of CEL and QUER at 31.6 mg/kg (D) or 100 mg/kg (E). In both, the first bar shows the antinociceptive effect of CEL and QUER in individual administration and represents the sum of the individual effects of the drugs (expected effect), while the second bar (with a white background) represents the antinociceptive effect obtained experimentally with the respective combination. * p < 0.05 vs. expected effect (addition of the antinociceptive effect of CEL and QUER in individual administration). Two-way ANOVA followed by Tukey’s test.

Figure 6

Area under the curve from the temporal courses of the effect of repeated administration (RA) of QUER on the antinociception induced by IND (A), KET (B), or CEL (C). In this protocol, the animals were pretreated with VEH (VEH-RA) or QUER 100 mg/kg/day for 10 days (QUER-RA). The administration of NSAIDs or saline solution (SS) was performed on the 11th day, 2 h after the intraarticular administration of uric acid. Each bar represents the mean ± SEM of six animals. The expected effect is the sum of SS + QUER-RA with the respective NSAID + QUER-RA, while the obtained effect is the experimental effect of each combination. * p < 0.05, unpaired two-tailed Student’s t-test.

Figure 7

Molecular docking analysis with COX-1 enzyme, 3D binding poses in the COX-1 active site showing hydrogen bonds and π-π interactions, and 2D interaction map highlighting interactions of (A) quercetin (QUER), (B) indomethacin (IND), (C) ketorolac (KET), and (D) celecoxib (CEL).

Figure 8

Molecular docking analysis with COX-2 enzyme, 3D binding poses in the COX-1 active site showing hydrogen bonds and π-π interactions, and 2D interaction map highlighting interactions of (A) quercetin (QUER), (B) indomethacin (IND), (C) ketorolac (KET), and (D) celecoxib (CEL).