Anti-ulcerogenic properties of Quassia amara L. (Simaroubaceae) standardized extracts in rodent models.

AIM OF THE STUDY: Quassia amara L. is commonly used in Costarican folk medicine. It has been used for the treatment of a broad range of gastrointestinal symptoms such as dyspepsia, gastritis and constipation. In this study, the gastroprotective activity of two standardized extracts of Quassia amara L., Lipro(®) and Ligas(®), was evaluated. MATERIALS AND METHODS: Anti-ulcerogenic properties were evaluated in female rats under acute ulcer-induction models (ethanol, indomethacin and hypotermic restraint). To get a deeper insight in the anti-ulcerogenic properties of the extracts, Ligas(®) was evaluated in the Shay rat model. Five parameters were estimated with this model: gastric mucus barrier, non-protein sulfhydril groups (NPSG) in the gastric mucosa, and pH, total acidity and peptic activity of the gastric juice. RESULTS: Induction of ulcers by 95% ethanol (0.5 mL per os), indomethacin (100 mg/kgs.c.) and stress (2h in hypothermic restraint) was inhibited significantly with administration of Lipro(®) (p<0.05), in a dosage range from 4.9 mg/kg/d to 48.9 mg/kg/d. Treatment was given for one week. The extract Ligas(®) showed a significant augmentation of NPSG (p<0.05) in a dosage range from 4.0 to 39.7 mg/kg. Ligas(®) did not produce a significant change (p>0.05) in the other indicators. CONCLUSIONS: Quassia amara L. standardized extracts, Lipro(®) and Ligas(®), showed an important anti-ulcerogenic effect in acute ulcer induction models. Their effect was related to an increase in gastric barrier mucus and non-protein sulfhydril groups.

Effect of Echinacea purpurea (Asteraceae) aqueous extract on antibody response to Bothrops asper venom and immune cell response

The effect of aqueous extract of Echinacea purpurea roots on the murine antibody response to Bothrops asper snake venom in vivo was studied. Three groups were used. Group #1, baseline control, was treated with snake venom plus PBS. Group #2 was treated with snake venom plus sodium alginate as adjuvant (routine method used at Instituto Clodomiro Picado), and group #3 or experimental group, was treated with snake venom plus aqueous extract ofE. purpurea root as adjuvant. In all groups, the first inoculation was done with Freund's complete adjuvant (FCA). By the time of the second bleeding, mice in group #3 showed a remarkable increment in the level of anti-venom antibodies compared with those in groups #1 or #2. In vitro immune cell proliferation as a response to aqueous extract of E. purpurea root was studied using human lymphocytes activated with different lectins (Con A, PHA and PWM). In all cases, increase in percentage of lymphoproliferation was greater when E. purpurea root extract was used in addition to individual lectins.

Effect of Echinacea purpurea (Asteraceae) aqueous extract on antibody response to Bothrops asper venom and immune cell response.

The effect of aqueous extract of Echinacea purpurea roots on the murine antibody response to Bothrops asper snake venom in vivo was studied. Three groups were used. Group #1, baseline control, was treated with snake venom plus PBS. Group #2 was treated with snake venom plus sodium alginate as adjuvant (routine method used at Instituto Clodomiro Picado), and group #3 or experimental group, was treated with snake venom plus aqueous extract ofE. purpurea root as adjuvant. In all groups, the first inoculation was done with Freund's complete adjuvant (FCA). By the time of the second bleeding, mice in group #3 showed a remarkable increment in the level of anti-venom antibodies compared with those in groups #1 or #2. In vitro immune cell proliferation as a response to aqueous extract of E. purpurea root was studied using human lymphocytes activated with different lectins (Con A, PHA and PWM). In all cases, increase in percentage of lymphoproliferation was greater when E. purpurea root extract was used in addition to individual lectins.

Edema induced by Bothrops asper (Squamata: Viperidae) snake venom and its inhibition by Costa Rican plant extracts

We tested the capacity of leaf (Urera baccifera, Loasa speciosa, Urtica leptuphylla, Chaptalia nutans, and Satureja viminea) and root (Uncaria tomentosa) extracts to inhibit edema induced by Bothrops asper snake venom. Edema-forming activity was studied plethysmographically in the rat hind paw model. Groups of rats were injected intraperitoneally with various doses of each extract and, one hour later, venom was injected subcutaneously in the right hind paw. Edema was assessed at various time intervals. The edematogenic activity was inhibited in those animals that received an injection U. tomentosa, C. nutans or L. speciosa extract. The extract of U. baccifera showed a slight inhibition of the venom effect. Extract from S. viminea and, to a lesser extent that of U. leptuphylla, induced a pro-inflammatory effect, increasing the edema at doses of 250 mg/kg at one and two hours.

Se investigó la capacidad de los extractos de las hojas de Urera baccifera, Loasa speciosa, Urtica leptuphylla, Chaptalia nutans, Satureja viminea y de la raíz de Uncaria tomentosa para inhibir el edema inducido por el veneno de Bothrops asper por métodos pletismométricos. Los grupos de ratas fueron inyectados intraperitonealmente con varias dosis de cada extracto y una hora mas tarde se inyectó veneno por vía subcutánea en la pata trasera derecha de la rata. Se evaluó el edema en distintos intervalos de tiempo. Los resultados muestran que la actividad edematogénica fue inhibida en los animales que recibieron los extractos de raíz de U. tomentosa, hojas de C. nutans y L. speciosa. Los extractos de hojas de U. baccifera mostraron leve inhibición del efecto del veneno. El extracto de hojas de S. viminea y en menor grado el de U. leptuphylla indujeron un efecto pro inflamatorio.

Edema induced by Bothrops asper (Squamata: Viperidae) snake venom and its inhibition by Costa Rican plant extracts.

We tested the capacity of leaf (Urera baccifera, Loasa speciosa, Urtica leptuphylla, Chaptalia nutans, and Satureja viminea) and root (Uncaria tomentosa) extracts to inhibit edema induced by Bothrops asper snake venom. Edema-forming activity was studied plethysmographically in the rat hind paw model. Groups of rats were injected intraperitoneally with various doses of each extract and, one hour later, venom was injected subcutaneously in the right hind paw. Edema was assessed at various time intervals. The edematogenic activity was inhibited in those animals that received an injection U. tomentosa, C. nutans or L. speciosa extract. The extract of U. baccifera showed a slight inhibition of the venom effect. Extract from S. viminea and, to a lesser extent that of U. leptuphylla, induced a pro-inflammatory effect, increasing the edema at doses of 250 mg/kg at one and two hours.

Anti-inflammatory activity of aqueous extracts of five Costa Rican medicinal plants in Sprague-Dawley rats

The anti-inflammatory properties of Loasa speciosa and Loasa triphylla (Loasaceae), Urtica leptuphylla and Urera baccifera (Urticaceae), and Chaptalia nutans (Asteracene) were studied using the carregeenan induced rat paw edema model. Aqueous extracts of each plant were made according to the ethnobotanical use. The hippocratic assay was made with female rats; the dose used was 500 mg/kg i.p. and the control group received 0.5 ml of n.s.s.. All the animals treated showed hypothermia, and those treated with the extracts of Chaptalia nutans, Urera baccifera and Urtica leptuphylla showed an increased colinergic activity. Acute toxicities of the aqueous extracts were studied in mice an the mean lethal doses ranged between 1.0226 and 1.2022 g/kg. The extracts of Urera baccifera, Chaptalia nutans, Loasa speciosa and Loasa triphylla (500 mg/kg i.p.) showed an anti-inflammatory activity comparable with that of indomethacin. The extracts of U. baccifera and C. nutans, which showed the greatest anti-inflammatory activity, did not show it when used orally (500 mg/kg p.o.).

Actividad anti-inflamatoria de Urera baccifera (Urticaceae) en ratas Sprague-Dawley / Anti-inflammatory activity of Urera baccifera (Urticacceae) in Sprague-Dawley rats

On a preliminary test, anti-inflammatory and analgesic dose-related activities on rats were observed for the aqueous fraction of Urera baccifera; this extract was biossay-guided fractionated and the final aqueous fraction was used according the ethnobotanical use. Carrageenan-induced edema (n=6), was used as an assay in the fractionating process. The anti-inflammatory and antinociceptive properties of the final aqueos fraction were studied using in vivo models. For the anti-inflammatory activity rat paw edema (n=6), pleurisy induced by carrageenan (n=6) and ear edema induced by topical croton oil (n=6) models were used, and tail-flick test (n=6), abdominal constrictions induced by acetic acid (n=6), and formalin test (n=6), were used for the antinociceptive activity. The test performed showed an inhibition effect on leukocyte migration, and a reduction on pleural exudate, as well as dose-dependant peripheral analgesic activity, at a range of 25-100 mg/kg i.p. The final aqueous fraction contains most of the anti-inflammatory activity of the plant U. baccifera. A possible mechanism of action is discussed and based on the results we conclude that this plant has a potencial for both anti-inflammatory and analgesic activity at the clinical level. Key words: Urera baccifera, anti-inflammatory agent, analgesic, antinociceptive, rat paw edema, Urticaceae