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The present study investigated the antinociceptive activity of different extracts prepared from the aerial parts of blossom of Hypericum grandifolium Choisy-a species native to the Macaronesian Region-using the acetic acid-induced writhing, formalin and tail flick test in mice. Oral administration of methanol extract (500 and 1,000 mg/kg p.o.), the aqueous, butanol and chloroform fractions (500 mg/kg p.o.) as well as subfractions F2 and F3 (45 mg/kg p.o.) from the chloroform fraction significantly inhibited acetic acid-induced writhing, with values ranging from 28 to 50% of inhibition. The methanol extract (1,000 mg/kg p.o.) and chloroform fraction (500 mg/kg p.o.) significantly reduced both phases of formalin-induced pain (with inhibition values ranging from 18 to 53%), whereas subfraction F2 (45 mg/kg p.o.) significantly inhibited the late phase (30%). In the tail flick assay, only the chloroform fraction (500 mg/kg p.o.) significantly prolonged the tail flick response. Different constituents, such as flavonoids and benzophenone derivatives, could account for the effects observed. Taking together, the results indicate that Hypericum grandifolium Choisy possesses both peripheral and central antinociceptive activities in mice, suggesting an interesting therapeutic potential for this species in pain diseases.

The present study investigates the analgesic and topical anti-inflammatory effects of the infusion, methanol extract and fractions of the aerial part in blossom of Hypericum reflexum L. fil. in mice. The acetic acid-induced writhing test, formalin test, tail flick test and the tetradecanoylphorbol acetate (TPA)-induced ear inflammation model in mice were used to determine these effects. Our findings show that oral administration of all extracts tested from this species significantly inhibit acetic acid-induced writhing in mice. Only the methanol extract and chloroform fraction were significantly active in both phases of formalin-induced pain and in the tail flick assays, suggesting that they may have central analgesic properties. On the other hand, the topical treatment of methanol extract, butanol and chloroform fractions of this species significantly reduced the TPA-induced ear oedema. In conclusion, the results indicate analgesic and topical anti-inflammatory activities in mice for the Hypericum species studied.

Different extracts and fractions from Sideritis candicans Ait. var. eriocephala Webb aerial part were investigated for their analgesic, anti-inflammatory and antimicrobial activities in mice. Results indicated that the extracts assayed showed anti-nociceptive activities because they were able to reduce the nociceptive response to chemical pain stimuli, such as in the acetic acid-induced writhing test. Moreover the extracts also possessed anti-inflammatory activity against carrageenan-induced paw oedema and TPA-induced ear oedema, being the chloroform fraction the most active. Further fractionation and analysis of this fraction revealed that the analgesic and anti-inflammatory activities found could be related in part to the presence of phytosterols, alpha and beta amyrin triterpenic derivatives and ent-kaurene type diterpenes in this species, since some of these compounds are endowed with these activities.

A previous chemical study of Sideritis canariensis var. pannosa demonstrated the presence of some important classes of related organic compounds with anti-inflammatory activities. In the present study, the crude ethanol extract and the chloroformic and aqueous fractions of S. canariensis have been examined for their antimicrobial actions through the disk-diffusion method and for their anti-inflammatory and analgesic effects in several animal models. No relevant antimicrobial activity against the tested microorganisms was found. The chloroformic fraction was the most interesting, exhibiting a good analgesic and anti-inflammatory activity.

Aethiopinone (1), an o-naphthoquinone diterpene from Salvia aethiopis L. roots and two hemisynthetic derivatives 2 and 3 have been evaluated for toxicity, anti-inflammatory, analgesic, antipyretic, and haemostatic activities. The compounds tested showed low toxicity and a pharmacological profile similar to other NSAI substances on reducing the edema induced by carrageenan and contractions induced by phenyl-p-quinone; the most active compounds were 1 and 2. In the same way and as expected with these types of substances, the bleeding time increased. In the TPA-induced ear inflammation model, the three compounds showed a moderate reduction of edema, and 1 produced a significant increase in the reaction time against thermal painful stimuli in the tail immersion test. The results demonstrated strong anti-inflammatory, peripheral and central analgesic properties for 1, as well as antiedematose topical action and peripheral analgesic properties for 2 and 3.