Ammi visnaga L (A.V.) is used in the traditional medicine for the treatment of kidney stones, diabetes and vitiligo. An in vivo anti-psoriasis, anti-inflammatory activities and oral toxicity studies of aqueous extract from seeds of Ammi visnaga L. was investigated. In the acute toxicity, the extract was administered orally in a single dose to rats (0- 2000-5000 mg/kg) and in the sub-acute toxicity daily for 28 days (0-300-600-1000 mg/kg/day). The symptoms of toxicity and mortality have been recorded daily and during 14 days of recovery with an examination of liver, kidney, hematologic, biochemical and histological analysis at the end of treatment. The anti-inflammatory activity was evaluated by induction of oedema and the anti-psoriasis by induction of a psoriasiform-like skin phenotype by UV-B radiations. No mortality was observed after single gavages by a dose up to 5000 mg/kg and no signs of toxicity noted. Clinical and biochemical examination during 28 days of gavages at all doses showed no significant difference compared to control group, while a significant reduction in MCV (mean corpuscular volume) and P-LCR (platelet large cell ratio) (p <0.05), PDW (platelet distribution width) and MPV (multi-purpose vehicle) (p <0.01) was observed and histopathological examinations showed slight inflammation in the liver and kidneys for the higher dose. Percentage of inhibition of the oedema was near the positive control 50% for all doses tested. Treatment with A.V. extract had decreased the thickness of the skin induced by UV-B irradiation.  In conclusion, the LD50 was estimated greater than 5000 mg/kg; therefore A.V. can be classified as non-toxic but if used in the long term can induce a slight toxicity dose dependant with high anti-psoriasis and anti-inflammatory activities.

Objectives: Psoriasis is a chronic skin inflammation disease, which is requires prolonged treatment, thereby interfering with the side effects of synthetic drugs. Traditional herbal medicine, and recent plant-based drugs, have been proven beneficial in reducing these side effects of synthetic drugs. Ammi visnaga L. species contains 2 furanochromones (khelline and visnagine) with a similar structure than psoralens that possess antipsoriatic activity. The objective of the present study was to verify the influence of extraction solvent on these two furanochromone content of Ammi visnaga and to study its immunomodulatory and antipsoriatic effect in vivo. Materials and Methods: In the present study, khellin and visnagin contents were compared between aqueous, hydroethanolic and ethyl acetate extracts of Ammi visnaga L. by highperformance liquid chromatography (HPLC), and their immunomodulating and antipsoriatic effects were studied for the hydroethanolic extract, in vivo, by hemagglutination test after immunization using human erythrocytes and by Psoriasis-like dermatitis induced using ultraviolet-C (UV-C) irradiations of two hours, during 3 successive days or by application of 2 a formaldehyde and Complete Freund adjuvant (CFA) mixture (1:10 ratio) during 3 successive days. Results: Ethanol at 60% showed the best results in the extraction of furanochromones (khellin and visnagin), followed by ethyl acetate and then by water. This hydroethanolic extract at 100 mg/kg showed an immunostimulating effect of the humoral response, by increasing the value of the hemagglutination antibody (HA) titer. The same extract, at a dose of 300 - 600 mg/kg orally or 2-4% topically, has a considerable antipsoriatic effect, reducing the psoriatic severity score (erythema and squaling), the epidermal thickness and the leukocytic infiltration. Conclusion: the 60% hydroethanol extract is better in the extraction of furanochromones from Ammi visnaga. This extract has considerable immunostimulant and antipsoriatic effects.