Purpose: Beside their prominent use as a spice, cardamom (Elettaria cardamomum) seeds have been employed since ancient times in the treatment of digestive and respiratory disorders. The cardamon plant itself is a tropical species, grown mostly in India and Central America. In Europe, the plants can achieve adequate vegetative growth; the variety with cinnamon-scented leaves is a popular ornamental indoor plant. The present study aimed to investigate the vegetative parts of European cardamom plants with regard to their potential use for medicinal purposes.
Material and methods. As a first step, a light microscopic study of leaf baldes, petioles, rhizomes and roots was performed, using free hand cross sections of Elettaria cardamomum (L.) Maton var. minuscula Burkill (voucher specimen 2017_CD_EC_1). Toluidine blue and Lugol’s iodine were employed to highlight anatomical features. Sudan III test was used for volatile oils. Tissues containing reducing polyphenols were pointed out microchemically with the Folin-Ciocalteu reagent. As a second step, antioxidant properties of two leaf extracts were established with the DPPH method. Extracts were prepared using 5 g crushed, fresh leaves and 100 mL solvent (water and ethanol 70%, respectively). The aqueous extract was prepared by boiling (10 minutes), the ethanolic one by ultrasonication for 10 minutes as well. After filtration, four dilutions were prepared for each extract and tested.
Results. Secretory idioblasts producing volatile oils were pointed out in both underground and aerial organs. They appear in the mesodermis of roots, cortical parenchyma of rhizomes, and epidermis of leaves. Their highest density was noted in the underground organs. Reducing polyphenols, visible in blue after treatment with Folin-Ciocalteu reagent, accumulate especially in leaf parenchyma. These anatomical features support the use of cardamon vegetative parts for medicinal applications. Due to preferential accumulation of polyphenols in leaves, these organs were further assayed in the DPPH test. While both the aqueous and the ethanol extracts had dose-dependent antioxidant effects, the ethanol one had a strongest one (IC50 = 10 mg/mL versus 25 mg/mL for the aqueous extract).
Conclusion. Our research could validate the relevance of employing vegetative organs of cardamom as a source of health-promoting products, due to their content in volatile oils and antioxidative polyphenols. Plants grown outside their tropical environment are suited as a prime matter as well.

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