Anti-inflammatory Effect of an Extract of Agave americana on Experimental Animals.

Background: Medicinal plants have the potential treasure to treat medical conditions for a long time based on error and trial method. Agave americana has been known as century plant or American aloe. The leaves contain genins, saponins, steroidal flavonoids, isoflavones, and coumarins. It has long been used for anti-inflammatory effects.

Objectives: This study was designed to evaluate the anti-inflammatory activity of the extract of A. americana .

Materials and Methods: A. americana leaves extract is collected and the extract is done by percolation method. Inflammation is induced in experimental animals' carrageenan-induced paw edema model and cotton pellet-induced granuloma model. The extract of A. americana and standard, aspirin and indomethacin are given orally for the anti-inflammatory effects. The anti-inflammatory effects were measured at regular intervals of time to see the percentage inhibition of paw edema and reduction of weight of granuloma with percentage protection to compare the effect of the extract with the control and standard.

Results: The extract of A. americana showed improved in percentage inhibition of paw edema in graded doses of hydroalcoholic extract of A. americana (HEAA) as compared with control in carrageenan-induced paw edema model. The percentage inhibition of 400 mg/kg of HEAA at the 3rd h is almost comparable with the standard, aspirin. On the other hand, graded doses (200 and 400 mg/kg) showed a highly significant reduction ( P < 0.001) in the weights of granuloma in comparison with the control in cotton pellet-induced granuloma model. The percentage inhibition of weight of granuloma by 400 mg/kg of HEAA is quite comparable to the standard, Indomethacin.

Conclusion: Anti-inflammatory activity is seen with the graded dose of HEAA. The plant contains flavonoids and genins which have been shown to have anti-edematous effects in the acute phase of inflammation. Thus, the plant contributes to its anti-inflammatory activity. Thus, higher doses of A. americana leaves need to be used to have the better understanding of the mechanism of anti-inflammation.

SUMMARY: The hydroalcoholic extract from Agave americana (100, 200, and 400 mg/kg, HEAA) were studied in carrageenan-induced paw edema model and cotton pellet-induced granuloma model in Wistar rats. The plant contains flavonoids and genins which have been shown to have anti-edematous effects in the acute phase of inflammation. The results were good with the higher doses of 200 and 400 mg/kg of HEAA. Its in vivo anti-inflammatory activity is in good agreement with the traditional use of A. americana . Abbreviation Used: HEAA: Hydroalcoholic extract of Agave americana leaves; SEM: Standard error mean; ANOVA: Analysis of variance; n: Number; g: gram; w/w: weight by weight; h: hour; kg: kilogram; mg: milligram.