Anti-inflammatory study on crude methanol extract and different fractions of Eremostachys laciniata

Eremostachys laciniata (L.) Bunge (Lamiaceae), which has been reported as a rich source of flavonoids, is one of the rarely explored species of the genus Eremostachys.

In this study, the crude methanol extract and different fractions of E. laciniata were investigated for in vivo anti-inflammatory properties.

Shade-dried leaves of E. laciniata were exhaustively extracted by percolation with methanol (80%) to obtain 250 g of crude methanol extract (El), followed by fractionation with different organic solvents to get the n-hexane (Elh), chloroform (Elc), ethyl acetate (Ele), butanol (Elb), and water (Elw) fractions. An in vivo anti-inflammatory study of the crude extract and sub-crude fractions was carried out in rats using the carrageenan model.

The Ele fraction was found to be the most potent inhibitor of edema formation by inducing a maximum inhibitory effect of 74.2% at the 300 mg/kg dose, during 3 h post carrageenan injection. The El extract and Elc fraction also showed good anti-inflammatory properties at the same dose.

The demonstration of excellent anti-inflammatory activity by the plant chiefly concentrating in the Ele fraction and the appearance of peak activity in the latter phase of the experiment suggested the presence of relatively low-polar substances with arachidonic acid metabolite inhibition property.

The plant may be an excellent source in the future for activity-guided isolation of important anti-inflammatory substances.