Marcelo D. Catarino

Pteridium aquilinum is a globally distributed plant species, highly adaptable to various environments and historically significant as a food source for both animals and humans. This study evaluated the in vivo effects of aqueous extracts from Pteridium aquilinum rhizomes and freeze-dried fiddleheads in a transgenic mouse model of human papillomavirus type 16 (HPV16)-induced cancer. Rhizome extract was administered in drinking water at concentrations of 0.0125, 0.025, and 0.05 g/mL for 28 days across six experimental groups (n = 5): G1 (wild-type, control), G2 (wild-type, 0.05 g/mL), G3 (HPV, control), G4 (HPV, 0.0125 g/mL), G5 (HPV, 0.025 g/mL), and G6 (HPV, 0.05 g/mL). Freeze-dried fiddleheads were incorporated into the diet at concentrations of 12.5%, 25%, and 50%, also using six groups (n = 5). Humane endpoints, body weight, and food and water consumption were monitored weekly. The rhizome extract was associated with more pronounced biological effects compared to fiddleheads, particularly at the histological and molecular levels. Conversely, freeze-dried fiddleheads were better tolerated. The results indicate that rhizomes were associated with great biological impact under the present experimental conditions, particularly in HPV16 transgenic mice, highlighting a potential synergistic effect with HPV. The potential risks associated with Pteridium aquilinum consumption, as well as preparation methods, should be carefully considered, even for rhizomes which are often regarded as less harmful than other plant parts.

Phlorotannins have gained significant attention for their potential bioactive and functional properties. However, these compounds are highly sensitive to gastrointestinal digestion, which limits their bioavailability and consequently the in vivo efficacy. To address this limitation, this study explored the use of various concentrations of γ‐ and β‐cyclodextrins in the aqueous microwave‐assisted extraction of phlorotannins from Fucus vesiculosus and submitted the resulting extracts to an in vitro gastrointestinal digestion protocol. While higher cyclodextrin concentrations resulted in an increase in extraction yields (from 47% to approximately 55% for both cyclodextrins), the opposite was observed for the total phlorotannin content. Notably, higher cyclodextrin concentrations markedly improved phlorotannin stability across the different stages of gastrointestinal digestion. Specifically, β‐cyclodextrin exhibited the highest protective effect, preventing phlorotannin degradation almost completely in both oral and gastric phases, and retaining approximately 35% (approximately 1.0 mg/g extract) of the initial content (approximately 3.0 mg/g extract) after the intestinal phase, thereby enhancing the compounds’ resistance and residence time in the intestinal lumen. A comparison between the addition of β‐cyclodextrin during extraction and post‐extraction revealed that, although both approaches reduce the phlorotannin loss throughout the gastrointestinal tract, the β‐cyclodextrin‐assisted extraction showed better efficacy. This indicates that strong guest‐host interactions are formed between phlorotannins and cyclodextrins during the extraction, possibly due to the increased enthalpy generated by microwave heating. Overall, this study highlights β‐cyclodextrin‐microwave‐assisted extraction as a promising approach to enhance the stability of phlorotannins in their transit through the gastrointestinal tract, ensuring their delivery to the intestinal lumen, where they can be released and available for absorption.

The genus Carthamus is recognized as an essential source of traditional medicine due to its immune-enhancing, antioxidant, and anti-cancer properties. This study aims to compare and determine the antioxidant and cytotoxic activities of the hydromethanolic and chloroformic extracts of the rhizome of Carthamus caeruleus L. The antioxidant activity was assessed using three radical scavenging methods, namely 2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTSŸ+ ), nitric oxide scavenging (NO·) and non-enzymatic radical scavenging (SO·). The potential cytotoxic was evaluated on several tumor cell lines, including gastric adenocarcinoma (AGS), colorectal adenocarcinoma (CaCo2), breast adenocarcinoma (MCF-7), lung carcinoma (NCI-H460), cervical adenocarcinoma (HeLa), and one non-tumor cell line of African green monkey kidney (VERO). The hydromethanolic extract was significantly more potent than the chloroformic extract for both activities evaluated, exhibiting IC50 values of 0.14 ± 0.008, 1.39 ± 0.27, and 0.89 ± 0.074 µg/mL in ABTSŸ+, NO·and SO·assays, respectively. As for cytotoxic potential, the hydromethanolic extract was particularly active against the NCI-H460 cells (IC50 value of 177.69 ± 1.90 µg/mL). These results suggest that the hydromethanoic extract of the rhizome of C. caeruleus could be used as an antioxidant and cytotoxic agent, supporting its traditional use as a treatment for burns.

The genus Carthamus is recognized as an essential source of traditional medicine due to its immune-enhancing, antioxidant, and anti-cancer properties. This study aims to compare and determine the antioxidant and cytotoxic activities of the hydromethanolic and chloroformic extracts of the rhizome of Carthamus caeruleus L. The antioxidant activity was assessed using three radical scavenging methods, namely 2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS+ ), nitric oxide scavenging (NO·) and non-enzymatic radical scavenging (SO·). The potential cytotoxic was evaluated on several tumor cell lines, including gastric adenocarcinoma (AGS), colorectal adenocarcinoma (CaCo2), breast adenocarcinoma (MCF-7), lung carcinoma (NCI-H460), cervical adenocarcinoma (HeLa), and one non-tumor cell line of African green monkey kidney (VERO). The hydromethanolic extract was significantly more potent than the chloroformic extract for both activities evaluated, exhibiting IC50 values of 0.14 ± 0.008, 1.39 ± 0.27, and 0.89 ± 0.074 µg/mL in ABTS+, NO·and SO·assays, respectively. As for cytotoxic potential, the hydromethanolic extract was particularly active against the NCI-H460 cells (IC50 value of 177.69 ± 1.90 µg/mL). These results suggest that the hydromethanoic extract of the rhizome of C. caeruleus could be used as an antioxidant and cytotoxic agent, supporting its traditional use as a treatment for burns. Keywords: Carthamus caeruleus L.; antioxidant activity; cytotoxic potential; radical scavenging.

Peganum harmala seeds crude hydro‐methanolic extract and their fractions (obtained with ethyl acetate and butan‐1‐ol) were analyzed and compared for their chemical profiles of alkaloids and polyphenols content. Moreover, their antioxidant, α‐glucosidase, acetylcholinesterase, and butyrylcholinesterase inhibitory activities were evaluated. The butan‐1‐ol fraction revealed the highest total phenolic content and exhibited the highest antioxidant capacity. From the inhibitory enzyme evaluations, it should be highlighted the butan‐1‐ol fraction inhibitory potential of ɑ‐glucosidase (the IC ₅₀ =141.18±4 μg/mL), which was better than the acarbose inhibitory effect (IC ₅₀ =203.41±1.07 μg/mL). The extracts’ chemical profile analysis revealed several compounds, in which quercetin dimethyl ether, harmine and harmaline emerged as the major compounds. The different solvents used impacted Peganum harmala seed contents and biological responses. Statistical analysis showed a significant correlation between bioactive compounds and biological activities. Thus, Peganum harmala seeds could be a promising natural source of bioactive compounds at the crossroads of many human diseases, and its cultivation may be encouraged.

Sargassum is one of the largest and most diverse genus of brown seaweeds, comprising of around 400 taxonomically accepted species. Many species of this genus have long been a part of human culture with applications as food, feed, and remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of natural antioxidant compounds of great interest, including polyphenols, carotenoids, meroterpenoids, phytosterols, and several others. Such compounds provide a valuable contribution to innovation that can translate, for instance, into the development of new ingredients for preventing product deterioration, particularly in food products, cosmetics or biostimulants to boost crops production and tolerance to abiotic stress. This manuscript revises the chemical composition of Sargassum seaweeds, highlighting their antioxidant secondary metabolites, their mechanism of action, and multiple applications in fields, including agriculture, food, and health.

Fucales are an order within the Phaeophyceae that include most of the common littoral seaweeds in temperate and subtropical coastal regions. Many species of this order have long been a part of human culture with applications as food, feedand remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of multiple bioactive compounds with great industrial interest. Among them, phlorotannins, a unique and diverse class of brown algae-exclusive phenolics, have gathered much attention during the last few years due to their numerous potential health benefits. However, due to their complex structural features, combined with the scarcity of standards, it poses a great challenge to the identification and characterization of these compounds, at least with the technology currently available. Nevertheless, much effort has been taken towards the elucidation of the structural features of phlorotannins, which have resulted in relevant insights into the chemistry of these compounds. In this context, this review addresses the major contributions and technological advances in the field of phlorotannins extraction and characterization, with a particular focus on Fucales.

A phlorotannin extract was obtained from Himanthalia elongata, revealing a profile rich in fucophlorethol-type and carmalol-type compounds. When subjected to simulated gastrointestinal digestion, its levels of total phlorotannins and antioxidant activity, measured in vitro via NO^● and O₂^●− scavenging assays, were reduced, thus suggesting that these compounds’ integrity and bioactivity are negatively affected by the digestive process. Nevertheless, when undigested vs. digested extracts were used on lipopolysaccharide-stimulated Raw 264.7 macrophages, both showed a strong inhibitory effect on the cellular NO^● production. In fact, although not statistically significant, the digested extract revealed a tendentially stronger effect compared to its undigested counterpart, suggesting that even though there is a decrease in the phlorotannins’ concentration after digestion, with a consequent loss of their scavenging properties, the possible degradation products being formed may exert their effects through the modulation of the intracellular signaling mechanisms. Overall, this study not only contributes to a better understanding of the phlorotannins’ composition of the species H. elongata, but also shows that, although the digestive process may affect the integrity and concentration of these compounds, this does not necessarily translate into loss of bioactivity, in particular the anti-inflammatory activity, probably owing to the bioactive effects that the degradation products of these phenolics may have at an intracellular level.