Hypericum grandifolium Choisy: a species native to Macaronesian Region with antidepressant effect.

AIM OF THE STUDY: Various species of Hypericum genus have been used in the Canary Islands as sedative, diuretic, vermifuge, wound healing, antihysteric and antidepressant agent. Studies have shown that methanol extract of Hypericum grandifolium Choisy is active in tetrabenazine-induced ptosis and forced swimming tests. In the current study, the aqueous, butanol and chloroform fractions obtained from the methanol extract as well as three sub-fractions derived from the chloroform fraction were evaluated for their central nervous effects in mice, particularly their antidepressant activity. MATERIALS AND METHODS: The central nervous effect of different fractions and sub-fractions of Hypericum grandifolium was evaluated in mice using various behavioural models including locomotor and muscle relaxant activity, forced swimming test, effect on normal body temperature, barbiturate-induced sleep, tetrabenazine-induced syndrome and 5-hydroxytryptohan-induced head twitches and syndrome. RESULTS: We found that the butanol and chloroform fractions and all sub-fractions showed an antidepressant effect in the forced swimming test, the chloroform fraction being the most active. They produced no effects or only a slight depression of locomotor activity. Chloroform fraction significantly increased the pentobarbital-induced sleeping time, produced a slight but significant hypothermia and antagonized tetrabenazine-induced ptosis, whereas the butanol fraction produced a slight potentiation of 5-HTP-induced head twitches and syndrome. CONCLUSIONS: The present results, together with previous pharmacological and phytochemical data, indicated that Hypericum grandifolium possess antidepressant-like effects in mice and that different constituents, such as the flavonoids and the benzophenone derivatives, could be responsible at least in part for the antidepressant effects observed for this species.

Antidepressant activity of some Hypericum reflexum L. fil. extracts in the forced swimming test in mice.

We previously reported that oral administration of the methanol extract obtained from the aerial part in blossom of Hypericum reflexum L. fil. was active in the tetrabenazine and forced swimming test. In the present study, the effect of the aqueous, butanol and chloroform fractions obtained from the methanol extract of this species on the central nervous system was investigated in mice, particularly in animal models of depression. Antidepressant activity was detected in the butanol and chloroform fractions of this species using the forced swimming test since both fractions induced a significant reduction of the immobility time, producing no effects or only a slight depression on spontaneous motor activity when assessed in a photocell activity meter. Moreover, these fractions did not alter significantly the pentobarbital-induced sleeping time. On the other hand, the chloroform fraction produced a slight but significant hypothermia and was also effective in antagonizing the ptosis induced by tetrabenazine. Furthermore, the butanol fraction produced a slight potentiation of the head twitches and syndrome induced by 5-HTP. Taken together, these data indicate that the butanol and chloroform fractions from Hypericum reflexum possess antidepressant-like effects in mice, providing further support for the traditional use of these plants in the Canary Islands folk medicine against central nervous disorders.

Evaluation of the analgesic and topical anti-inflammatory effects of Hypericum reflexum L. fil.

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.

Antidepressant properties of some Hypericum canariense L. and Hypericum glandulosum Ait. extracts in the forced swimming test in mice.

It has been shown in a previous work that the methanol extract obtained from the aerial part in blossom of Hypericum canariense L. and Hypericum glandulosum Ait. was active in the tetrabenazine and forced swimming test. In the present study, the central nervous effect of the aqueous, butanol and chloroform fractions obtained from the methanol extracts of these Hypericum species was investigated in mice, particularly in animal models of depression. It was found that the immobility time in the forced swimming test was significantly reduced by the butanol and chloroform fraction of both species assayed, producing no effects or only a slight depression on spontaneous motor activity when assessed in a photocell activity meter. In this regard, the efficacy of the chloroform extract from Hypericum glandulosum Ait. (500 mg/kg p.o.) in the forced swimming test was comparable to that of the tricyclic antidepressant imipramine (50 mg/kg p.o.). In addition, the Hypericum glandulosum chloroform fraction was also effective in antagonizing the ptosis induced by tetrabenazine. Moreover, Hypericum canariense butanol fraction and Hypericum glandulosum chloroform fraction produced a slight but significant hypothermia. Taken together, these data demonstrate that the butanol and chloroform fractions from Hypericum canariense and Hypericum glandulosum possess antidepressant-like effects in mice, providing further support for the traditional use of these plants in the Canary Islands folk medicine against central nervous disorders.

Analgesic and topical anti-inflammatory activity of Hypericum canariense L. and Hypericum glandulosum Ait.

The present study investigates the analgesic and topical anti-inflammatory activities of the infusion, methanol extract and fractions of the aerial part in blossom of Hypericum canariense L. and Hypericum glandulosum Ait. in mice. The acetic acid-induced writhing 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 methanol extracts, and the aqueous, butanol and chloroform fractions of both species and the infusions of Hypericum glandulosum significantly inhibit acetic acid-induced writhing in mice. Only the infusion, methanol extract and butanol and chloroform fractions of Hypericum glandulosum were significantly active in the tail flick assay, suggesting that they may have central analgesic properties. On the other hand, the topical treatment of all extracts tested from both species, with the exception of the infusions and the Hypericum canariense aqueous fraction, 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.

Studies on the analgesic and anti-inflammatory effects of Sideritis candicans Ait. var. eriocephala Webb aerial part.

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.

Antimicrobial studies on three species of Hypericum from the Canary Islands.

The antimicrobial activity of several extracts and fractions of the aerial parts of Hypericum canariense, Hypericum glandulosum and Hypericum grandifolium was investigated using the disc diffusion and broth microdilution methods against twelve reference microorganisms (eight bacterial and four fungal strains). The methanol extract and chloroform fraction of H. canariense, as well as the methanol extracts, butanol and chloroform fractions of both H. glandulosum and H. grandifolium exhibited a good antibacterial activity against four Gram-positive bacteria (Bacillus cereus var. mycoides, Micrococcus luteus, Staphylococcus aureus and Staphylococcus epidermidis) and the Gram-negative bacterium Bordetella bronchiseptica with the diameters of growth inhibition area in the range 10-25 mm and MICs values between 0.03 and 0.29 mg/ml. Neither the infusions and aqueous fractions of the species studied nor the butanol fraction of H. canariense showed any antibacterial activity against the tested microorganisms. Amongst the active extracts, the minimum inhibitory concentration (MIC) determination showed that the H. canariense chloroform fraction was the most active against M. luteus, S. aureus and S. epidermidis. No antifungal activity was seen with any of the extracts or fractions tested. The results of this study support the use of these species in Canarian traditional medicine to treat skin infections.

Antidepressant effects of the methanol extract of several Hypericum species from the Canary Islands.

The aim of the present study was to investigate several neuropharmacological effects of the methanol extract of the aerial parts in blossom of Hypericum canariense, H. glandulosum, H. grandifolium and H. reflexum (Hypericaceae). These extracts did not alter significantly the locomotor activity, body temperature or the pentobarbital-induced sleeping time, with the exception of H. reflexum which significantly potentiated pentobarbital-induced sleeping time at both doses assayed (500 and 1000 mg/kg p.o.). Additionally, neither muscle relaxant nor anticholinergic activity was observed. These extracts antagonized the ptosis and/or motor depression induced by tetrabenazine and also shortened the immobility time in the forced swimming test. Moreover, the H. glandulosum and H. grandifolium extracts at 1000 mg/kg p.o. potentiated the head twitches induced by 5-HTP. These observations suggest that the methanol extract of the Hypericum species in doses of 500-1000 mg/kg p.o. possess antidepressant activity in mice, without inducing significant muscle relaxation, anticholinergic and sedative properties.

Effects of Visnea mocanera extracts on the bleeding time, gastrointestinal transit and diuresis in rodents.

The present study examined the effect of several extracts of Visnea mocanera L. on the bleeding time and gastrointestinal transit in mice using the Duke test and charcoal meal method, respectively; they were also investigated in order to examine their renal effects. Results showed that V. mocanera extracts significantly inhibited both the bleeding time and gastrointestinal transit in mice. No diuretic activity of these extracts were detected. In contrast, they significantly reduced the urine volume. The study provides experimental support to the therapeutic advocation of V. mocanera in ethnomedicine for the treatment of diarrhoea and the healing of wounds.

Cytostatic and antibacterial activity of some compounds isolated from several lamiaceae species from the canary islands.

A chemotherapeutic study has been carried out on thirteen products Eeleven diterpenes, one lignan, (+)-sesamin, and a coumarin, siderin] isolated from SALVIA and SIDERITIS species considered endemic to the Canarian flora. The data obtained suggest that some diterpenoid compounds show an interesting cytostatic activity, specially galdosol ( 6) with an ID (50) value of 0.5 microg/ml. These compounds also evidence a moderate antibacterial activity against Gram positive bacteria.

New contribution to the ethnopharmacological study of the Canary Islands.

We present in this paper a report of 155 species used for medicinal purpose in the Canary Islands. These species have been compiled in 13 tables in accordance with their main medicinal use, indicating also other possible popular uses. We have made a short inventory of the rates of the most important medicinal applications. This new compilation shows once more the traditional use of the phytotherapeutic resources by the Canary population and also the wide possibilities of the phytochemical and pharmacological investigations of the Canary Islands Flora.