Monographic Quality Parameters and Genotoxicity Assessment of Asphodelus bento-rainhae and Asphodelus macrocarpus Root Tubers as Herbal Medicines

Abstract

Root tubers of Asphodelus bento-rainhae subsp. bento-rainhae (AbR), an endemic species with relevant interest due to conservation concerns, and Asphodelus macrocarpus subsp. macrocarpus (AmR) have been traditionally used for culinary and medicinal purposes, mainly associated with skin infection and inflammation. The present study aims to establish the quality control criteria for the proper characterization of dried root tubers of both species as herbal substances, together with their preclinical safety assessments. Botanical identification using macroscopic and microscopic techniques and phytochemical evaluation/quantification of the main classes of marker secondary metabolites, including phenolic compounds (flavonoid, anthraquinone, condensed and hydrolysable tannin) and terpenoids were performed. Additionally, in vitro genotoxicity/mutagenicity was evaluated by Ames test. Evident morphological differences in the development of tubercles (3.5 × 1 cm in AbR and 8.7 × 1.4 cm in AmR) and microscopicly in the arrangements and characteristics of the vascular cylinder (metaxylem and protoxylems) were found. Anatomical similarities such as multiple-layered epidermis (velamen) and the cortex area with thin-walled idioblasts (134 ± 2.9 µm and 150 ± 27.6 µm) containing raphide crystals (37.2 ± 14.2 µm and 87.7 ± 15.3 µm) were observed between AbR and AmR, respectively. Terpenoids (173.88 ± 29.82 and 180.55 ± 10.57 mg OAE/g dried weight) and condensed tannins (128.64 ± 14.05 and 108.35 ± 20.37 mg CAE/g dried weight) were found to be the main class of marker secondary metabolites of AbR and AmR extracts, respectively. No genotoxicity (up to 5 mg/plate, without metabolic activation) was detected in these medicinal plants’ tested extracts. The obtained results will contribute to the knowledge of the value of the Portuguese flora and their future commercial cultivation utilization as raw materials for industrial and pharmaceutical use.

Bioguided Identification of Active Antimicrobial Compounds from Asphodelus bento-rainhae and Asphodelus macrocarpus Root Tubers

“…Hyphenated analytical techniques were applied for the phytochemical dereplication of the samples. Following our previous study's results [25], the chromatographic profiles of AbR and AmR extracts showed excellent qualitative similarity in their chemical composition, characterized by the presence of terpenoids, phenolic acids and anthracene derivatives. Therefore, in continuation of the above-mentioned study searching for potent antimicrobial metabolites from these Portuguese Asphodelus species, liquid-liquid frac-tionations of both plant extracts with increasingly polar solvents, namely diethyl ether (AbR-1, AmR-1), ethyl acetate (AbR-2, AmR-2) and water (AbR-3, AmR-3), were performed.…”

“…Although the negative results of the genotoxic/mutagenic potential of the root tuber 70% hydroethanolic extracts of both species were previously reported by the authors [ 25 ], as suggested by the guidelines [ 45 ], a genotoxicity assessment of different herbal preparations should be evaluated in order to reflect, as far as possible, the full spectrum of the extracted components. Additionally, since the AbR 96% hydroethanolic extract exhibited the highest antimicrobial activity and quantity of the active secondary metabolites, it was selected for further genotoxicity/mutagenicity evaluations.…”

“…The collected samples were dried in a well-ventilated dark space at room temperature. The authors’ previous monographic study give a more detailed description of both species’ botanical identification and sample selections [ 25 ].…”

Multitemporal Land Use and Cover Analysis Coupled with Climatic Change Scenarios to Protect the Endangered Taxon Asphodelus bento-rainhae subsp. bento-rainhae

“…Therefore, the appropriate management of AbR areas is vital for successful conservation and further biodiversity maintenance. Furthermore, the species’ medicinal and other economic properties [ 24 ] emphasize further the importance of conservation, including a putative increase in area due to potential economic species use. Nevertheless, studies about the impact of soil N accumulation in AbR are unknown, which might be an extra driver to take into consideration in this taxon’s protection.…”

“…AbR might have economic value. A recent study characterized the substances in the dried root tubers and showed that terpenoids were the main class of secondary metabolites in the extracts [ 24 ]. The leaves of AbR were used as food and in traditional medicine to treat ulcers and urinary and inflammatory disorders [ 25 ], and also as fertilizer and fodder in Portugal [ 26 ].…”