The present invention describes a method for completely extracting the alkaloid fraction (montanine) of Rhodophiala bifida (Herb.) Traub from bulbs of Rhodophiala bifida. The present invention further describes a method for treating inflammation using pharmaceutical compositions containing the alkaloid fraction of Rhodophiala bifida as the active ingredient. The present invention therefore comprises an extraction method that is faster than other extraction methods described in the literature for the alkaloid fraction of Rhodophiala bifida, dispensing with numerous changes of solvent in order to strain the plant, and the use thereof as an anti-inflammatory. The present invention is further characterised by the development of an anti-inflammatory medicinal drug for treating and preventing diseases involving inflammation and/or the local increase in the number of fibroblasts as its etiopathogenesis, such as: rheumatoid arthritis, ulcerative colitis, sepsis, acute pulmonary disease, inflammatory infections, in particular inflammatory and fibrosing diseases related to the lungs and kidneys, osteoporosis, Castleman disease, psoriatic arthritis, juvenile chronic arthritis and other non-specific inflammatory joint diseases.
