M. T. Sáenz

Antibacterial activity of the phenolic acids fractions of Scrophularia frutescens and Scrophularia sambucifolia

The phenolic fractions of aerial part of Scrophularia frutescens and S. sambucifolia (Scrophulariaceae) showed a potent antibacterial activity. Ferulic, isovanillic, p-hydroxycinnamic, p-hydroxybenzoic, syringic, caffeic, gentisic and protocatechuic acids were isolated from S. frutescens and ferulic, p-coumaric, vanillic, p-hydroxibenzoic and syringic acids were isolated from S. sambucifolia. Since phenolic acids have been shown in the literature to exert an antibacterial effect, the presence of these compounds in the two plants explains their antibacterial activity.

Topical antiinflammatory activity of phytosterols isolated from Eryngium foetidum on chronic and acute inflammation models

Eryngium foetidum L. (Apiaceae) is a Caribbean endemic plant, used in folk medicine for the treatment of several antiinflammatory disorders. A preliminary phytochemical study showed that the hexane extract is rich in terpenic compounds. Chromatographic fractionation of this extract yielded: α‐cholesterol, brassicasterol, campesterol, stigmasterol (as the main component, 95%) clerosterol, β‐sitosterol, Δ5‐ avenasterol, Δ524‐stigmastadienol and Δ7‐avenasterol. The topical antiinflammatory activity of the hexane extract and of stigmasterol was evaluated by auricular oedema, induced by 12‐0‐tetradecanoylphorbol acetate (TPA), in the mouse, using single and multiple applications of the phlogistic agent. Both reduced the oedema in a similar proportion in the two model assays (acute and chronic). Meloperoxidase activity was strongly reduced by both the extract and the compound, in the acute but not the chronic model.

Anti‐inflammatory activity of abietic acid, a diterpene isolated from Pimenta racemosa var. grissea

The anti‐inflammatory activity of abietic acid, a diterpene isolated from Pimenta racemosa var. grissea (Myrtaceae), was evaluated in‐vivo and in‐vitro. This compound significantly inhibited rat paw oedema induced by carrageenan in a time‐ and dose‐dependent manner, and mouse ear oedema induced by 12‐O‐tetradecanoylphorbol acetate, after oral or topical administration. The inhibition of myeloperoxidase enzyme showed that its topical activity was influenced by neutrophil infiltration into the inflamed tissues (ears). In addition, the effect of abietic acid on some macrophage functions was analysed in‐vitro. Non‐toxic concentrations of abietic acid inhibited prostaglandin E2 (PGE2) production in lipopolysaccharide‐treated macrophages, whereas nitrite, tumour necrosis factor α and interleukin‐1β production were only weakly affected by this diterpene. PGE2 production from A23187‐stimulated macrophages was only inhibited at high doses (100 μM) and it failed to modify leukotriene C4 production. These results indicate that abietic acid exerts in‐vivo anti‐inflammatory activity after oral or topical administration and has partial ability to prevent the production of some inflammatory mediators.

STUDY OF THE TOPICAL ANTI-INFLAMMATORY ACTIVITY OF ACHILLEA AGERATUM ON CHRONIC AND ACUTE INFLAMMATION MODELS

We have produced a chloroform extract from Achillea which includes stigmasterol and sitosterol. By comparing it with the pure compounds an anti-inflammatory effect (with mouse ears) is assumed. The topical anti-inflammatory effect of the chloroform extract from Achillea ageratum (Asteraceae)and of stigmasterol and β-sitosterol, isolated of this extract has been evaluated, against to 12-0-tetradecanoylphorbol acetate (TPA )-induced mouse ear edema, using simple (acute model) and multiple applications (chronic model) of the phlogistic agent. Myeloperoxydase activity also was studied in the inflamed ears. In the acute model the extract exerted a dose-dependent effect. All the doses assayed (1, 3 and 5 mg/ear) significantly reduced the edema (50% , 66% and 82 % , respectively). The isolated sterols stigmasterol and β-sitosterol (with doses of 0.5 mg/ear) had similar effect as the extract with doses of 1 and 3 mg (59% and 65% respectively). In the chronic model the anti-inflammatory effect generally was a more moderate one. The highest dose of the extract decreased the edema reduction to 26% with the highest dose of the extract applied. With the compounds the effect decreased to 36% with stigmasterol, and 40.6% with β-sitosterol. Myeloperoxydase activity (MPO ) was reduced by the extract and the compounds in the acute model, however, in the chronic edema, the enzyme inhibition was very weak with all treatments even with the standard substance. These results indicate that the chloroform extract of Achillea ageratum and some of the its components stigmasterol and β-sitosterol are more effective as topical anti-inflammatory agents in acute than in the chronic process and their action is markedly influenced by the inhibition of neutrophil migration into inflamed tissue.

Anti-inflammatory activity of Agave intermixta Trel. and Cissus sicyoides L., species used in the Caribbean traditional medicine.

Agave intermixta Trel. and Cissus sicyoides L. are two tropical plants originating from the Dominican Republic. Aqueous extracts from these species are used in traditional medicine. In contrast, biological activity and toxicity of these plants are not yet evaluated systematically. The aim of the present work is to investigate a potential anti-inflammatory activity, and to elucidate the toxicity of the extracts. No lethal effects were produced after oral administration of the extracts. The values of the medium lethal doses after intraperitoneal administration were quite high for both species, although A. intermixta seems to be rather more toxic than C. sicyoides. The anti-inflammatory effects have been investigated in two experimental in vivo models. The carrageenan-induced rat paw oedema was chosen as a model for general inflammation, and the mice ear oedema test using tetradecanoylphorbol acetate as inflammatory agent as a model of topical inflammation. Dry extracts from decoctions of A. intermixta leaves and C. sicyoides stems were administered in doses of 300 and 500 mg/kg (p.o.) in the general model, and in doses of 3 and 5 mg/mouse ear for both plants in the topical model. In the general anti-inflammation assay, the oral administration of both extracts produced a significant anti-inflammatory effect, most pronounced for A. intermixta than for C. sicyoides. In the topical model, the administration of both extracts produced similar inhibitions of the oedema, with a reduction of approximately 50% in comparison with the control group. In homogenated tissue samples from the inflamed areas, a distinct decrease in the level of myeloperoxidase enzyme was noted.

Cytostatic activity of some compounds from the unsaponifiable fraction obtained from virgin olive oil

Oleuropein, tyrosol, squalene and the fraction of sterols and triterpenoid dialcohols from the unsaponifiable fraction obtained from virgin olive oil have been tested for possible cytostatic activity against McCoy cells, using 6-mercaptopurine as a positive control. The samples of sterols and triterpenic dialcohols showed a strong activity.

ANALGESIC, ANTIPYRETIC AND ANTI-INFLAMMATORY EFFECTS OF ACHILLEA AGERATUM

The aqueous and methanol extracts of Achillea ageratum L. (Asteraceae) have been evaluated for analgesic, antipyretic and antiinflammatory properties in mice and rats in several experimental models. The aqueous extract exhibited significant activity in the analgesic and antiinflammatory assays but was unable to reduce hyperthermia. Moreover, the methanol extract exerted effects in three pharmacological actions. The phytochemical investigation of this latter extract revealed the presence of flavonic compounds: luteolin, quercetin and 7‐O‐β‐luteolin.

Antibacterial Activity and Composition of the Volatile Oil from Achillea Ageratum L.

Artemisia ketone, artemisia alcohol, β‐caryophyllene oxide and 1,8‐cineole were confirmed as the major components of the volatile oil from Achillea ageratum L. In an antibacterial diffusion assay, the volatile oil showed activity mainly against Gram‐positive bacteria Bacillus sp. and Staphylococcus aureus. The oil also showed some activity against the Gram‐negative bacteria, Escherichia coli.

Topical anti-inflammatory effect of tirucallol, a triterpene isolated from Euphorbia lactea latex

Latex from Euphorbia lactea (Euphorbiaceae), a native Dominican medicinal plant, is claimed to be useful in the treatment of inflammation. Topical application of tirucallol, a tetracyclic triterpene isolated from Euphorbia lacteal latex, suppressed ear edema in the mouse model in a dose-dependent manner, as well as affecting the influx of polymorphonuclear cells in response to topical application of 12-O-tetradecanoylphorbol-acetate (TPA) in the mouse ear. In addition, the effect of tirucallol, on some macrophage functions was analyzed in vitro. Non-toxic concentrations of tirucallol potently inhibited nitrite production in lipopolysaccharide-stimulated macrophages. Western blot analysis showed that nitric oxide reduction was a consequence of the inhibition of inducible nitric oxide synthetase expression although tirucallol slightly affected to prostaglandin E(2) (PGE(2)) generation. The results of the study revealed that tirucallol (0.3%), present in Euphorbia lactea latex, exerts a topical anti-inflammatory effect in vivo, via a mechanism of action related to the neutrophil migration. On the other hand, it can be deduced that the mechanism of the anti-inflammatory activity of this triterpene is related to the control of the production of NO and its effect on the expression of iNOS.

Antinociceptive effects of the tubercles of Anredera leptostachys.

The tubercles of Anredera leptostachys are used as an antinociceptive and anti-inflammatory in the popular medicine of the Caribbean basin. In the present work, the anti-nociceptive and central nervous system depressant (CNS) effects of the methanolic extract from the tubercles of A. leptostachys have been evaluated. The antinociceptive activity was assayed in several experimental models in mice: acetic acid, formalin and hot plate tests. The methanolic extract (250 and 500 mg/kg) significantly and in a dose-dependent manner reduced the nociception induced by the acetic acid (P < 0.001). In the hot plate test, the extract significantly increased the latency time of jump although it slightly increased the licking time. The naloxone partially reversed the antinociception of the extract in the hot plate test. In the formalin test, the methanolic extract also significantly reduced the painful stimulus but the effect was not dose-dependent. In the study of the CNS-depressant effects, the extract was found to produce a significant reduction of the exploratory capacity with both doses assayed (P < 0.001). The muscular relaxation only decreased with the higher doses assayed (P < 0.001). The escape instinct was also significantly reduced (P < 0.001) by the two doses of the extract and both were more effective than standard drugs morphine and diazepam.