Phytochemical Profiles, Physicochemical Analysis, and Biological Activity of Three Colchicum Species

Background: Colchicum is a genus of the Colchicaceae family with various isolated compounds, especially tropolone alkaloids and flavonoids, which are used for osteoarthritis, gout, cancer, inflammatory diseases, jaundice, and sexual impotence in different societies. Objectives: The current study aimed to evaluate the phytochemical and physicochemical properties and anti-inflammatory activities of three Colchicum species. Methods: Total tropolone alkaloid, total phenolic/total tannin, and total flavonoid contents were determined using acidic potassium dichromate, Folin-Ciocalteu, and aluminum chloride methods, respectively. Moreover, the HPLC method was used for identification and quantitation purposes of tropolone alkaloids. Physicochemical properties of three Colchicum species, including macroscopic and organoleptic properties, solubility, foreign matter, ash values, and heavy metal contents, were evaluated. Besides, in vitro anti-inflammatory activities of the corms also were determined using the protein denaturation technique as a rapid screening method. Results: The highest levels of tropolone alkaloid, phenolic compounds, tannins, and flavonoids were observed in C. autumnale, C. speciosum, and C. robustum, respectively. HPLC analysis indicated the presence of colchicine, demecolcine, 2-demethyl colchicine, 3-demethyl colchicine, colchicoside, colchifoline, cornigerine, and N-deacetyl-N-formyl colchicine in these Colchicum species. The physicochemical properties of C. speciosum and C. robustum corms are appropriate compared to the standard Colchicum autumnale corm. Moreover, all Colchicum species exhibited high anti-inflammatory activities compared to standard drugs. Conclusions: This study demonstrated that the corm of the Colchicum species contained similar main compounds with different amounts, as well as appropriate physicochemical properties. Moreover, the valuable biological effects of these plants stimulate the cultivations on a large scale.