Antinociceptive and anti-inflammatory effects of Crocus sativus L. stigma and petal extracts in mice

Abstract

Background: Crocus sativus L. (saffron) is used in folk medicine, for example as an antiedematogenic agent. We aimed to evaluate the antinociceptive and anti-inflammatory activity of saffron extracts in mice.

Results: We used aqueous and ethanolic maceration extracts of Crocus sativus L. stigma and petals. Antinociceptive activity was examined using the hot plate and writhing tests. The effect of extracts against acute inflammation was studied using xylene induced ear edema in mice. The activity of the extracts against chronic inflammation was assessed by formalin-induced edema in the rat paw. In the hot plate tests, intraperitoneal injection of both extracts showed no significant antinociceptive activity in mice. The extracts exhibited antinociceptive activity against acetic acid induced writhing. Naloxone partially blocked only the antinociceptive activity of the stigma aqueous extract. Only the stigma extracts showed weak to moderate effect against acute inflammation. In chronic inflammation, both aqueous and ethanolic stigma extracts, as well as ethanolic petal extract, exerted anti-inflammatory effects.

Conclusions: We conclude that aqueous and ethanolic extracts of saffron stigma and petal have an antinociceptive effect, as well as acute and/or chronic anti-inflammatory activity.

Figure 1

Effect of a subcutaneous injection of naloxone on the antinociceptive effect of intraperitoneally administered Crocus sativus petal aqueous extract, morphine and diclofenac on acetic acid-induced writhing test in mice. Values are the mean ± S.E.M. of writhes number for 8 mice, ^**P<0.01, ^***P<0.001, compared to control (normal saline); +++P<0.001, compared to morphine plus naloxone, Tukey-Kramer test.

Figure 2

Effect of a subcutaneous injection of naloxone on the antinociceptive effect of intraperitoneally administered Crocus sativus petal ethanolic extract, morphine and diclofenac on acetic acid-induced writhing test in mice. Values are the mean ± S.E.M. of writhes number for 8 mice, ^***P<0.001, compared to control (normal saline); +++P<0.001, compared to morphine plus naloxone, Tukey-Kramer test.

Figure 3

Effect of a subcutaneous injection of naloxone on the antinociceptive effect of intraperitoneally administered Crocus sativus stigma aqueous extract, morphine and diclofenac on acetic acid-induced writhing test in mice. Values are the mean ± S.E.M. of writhes number for 8 mice, ^***P<0.001, compared to control (normal saline); +++P<0.001, compared to morphine (or extract) plus naloxone, Tukey-Kramer test.

Figure 4

Effect of a subcutaneous injection of naloxone on the antinociceptive effect of intraperitoneally administered Crocus sativus stigma ethanolic extract, morphine and diclofenac on acetic acid-induced writhing test in mice. Values are the mean ± S.E.M. of writhes number for 8 mice, ^***P<0.001, compared to control (normal saline); +++P<0.001, compared to morphine plus naloxone, Tukey-Kramer test.

Figure 5

Effect of the aqueous extract of Crocus sativus petal and morphine (i.p.) on pain threshold of mice in the hot-plate test. Each point represents the mean ± S.E.M. of reaction time for n = 8 experiments on mice. ^***P<0.001, compared to control (normal saline), Tukey-Kramer test.

Figure 6

Effect of the ethanolic extract of Crocus sativus petal and morphine (i.p.) on pain threshold of mice in the hot-plate test. Each point represents the mean ± S.E.M. of reaction time for n = 8 experiments on mice. ^***P<0.001, compared to control (normal saline), Tukey-Kramer test.

Figure 7

Effect of the aqueous extract of Crocus sativus stigma and morphine (i.p.) on pain threshold of mice in the hot-plate test. Each point represents the mean ± S.E.M. of reaction time for n = 8 experiments on mice. ^***P<0.001, compared to control (normal saline), Tukey-Kramer test.

Figure 8

Effect of the ethanolic extract of Crocus sativus stigma and morphine (i.p.) on pain threshold of mice in the hot-plate test. Each point represents the mean ± S.E.M. of reaction time for n = 8 experiments on mice. ^***P<0.001, compared to control (normal saline), Tukey-Kramer test.

Figure 9

Effect of petal Crocus sativus aqueous and ethanolic extracts and diclofenac on formaldehyde induced arthritis in hind paw of rats. The inflammation was produced by subaponeurotic injection of 0.1 ml of 2% formaldehyde in the right hind paw of the rats on the first and third day. The animals were treated daily with the extracts or diclofenac intraperitoneally for 10 days. All agents were administered intraperitoneally. Each point represents the mean ± S.E.M. of change of hind paw size for 6 rats. Only the ethanolic extracts and diclofenac were effective compared to control (normal saline), Tukey-Kramer.

Figure 10

Effect of stigma Crocus sativus aqueous and ethanolic extracts and diclofenac on formaldehyde induced arthritis in hind paw of rats. The inflammation was produced by subaponeurotic injection of 0.1 ml of 2% formaldehyde in the right hind paw of the rats on the first and third day. The animals were treated daily with the extracts or diclofenac intraperitoneally for 10 days. All agents were administered intraperitoneally. Each point represents the mean ± S.E.M. of change of paw size for 6 rats. Both extracts and diclofenac were effective compared to control (normal saline), Tukey-Kramer.