The traditional utilization, biological activity and chemical composition of edible fern species.

ETHNOPHARMACOLOGICAL RELEVANCE: Ferns form an important part of the human diet. Young fern fiddleheads are mostly consumed as vegetables, while the rhizomes are often extracted for starch. These edible ferns are also often employed in traditional medicine, where all parts of the plant are used, mostly to prepare extracts. These extracts are applied either externally as lotions and baths or internally as potions, decoctions and teas. Ailments traditionally treated with ferns include coughs, colds, fevers, pain, burns and wounds, asthma, rheumatism, diarrhoea, or skin diseases (eczema, rashes, itching, leprosy). AIM OF THE REVIEW: This review aims to compile the worldwide knowledge on the traditional medicinal uses of edible fern species correlating to reported biological activities and isolated bioactive compounds. MATERIALS AND METHODS: The articles and books published on edible fern species were searched through the online databases Web of Science, Pubmed and Google Scholar, with critical evaluation of the hits. The time period up to the end of 2022 was included. RESULTS: First, the edible fern species were identified based on the literature data. A total of 90 fern species were identified that are eaten around the world and are also used in traditional medicine. Ailments treated are often associated with inflammation or bacterial infection. However, only the most common and well-known fern species, were investigated for their biological activity. The most studied species are Blechnum orientale L., Cibotium barometz (L.) J. Sm., Diplazium esculentum (Retz.) Sw., Marsilea minuta L., Osmunda japonica Thunb., Polypodium vulgare L., and Stenochlaena palustris (Burm.) Bedd. Most of the fern extracts have been studied for their antioxidant, anti-inflammatory and antimicrobial activities. Not surprisingly, antioxidant capacity has been the most studied, with results reported for 28 edible fern species. Ferns have been found to be very rich sources of flavonoids, polyphenols, polyunsaturated fatty acids, carotenoids, terpenoids and steroids and most of these compounds are remarkable free radical scavengers responsible for the outstanding antioxidant capacity of fern extracts. As far as clinical trials are concerned, extracts from only three edible fern species have been evaluated. CONCLUSIONS: The extracts of edible fern species exert antioxidant anti-inflammatory and related biological activities, which is consistent with their traditional medicinal use in the treatment of wounds, burns, colds, coughs, skin diseases and intestinal diseases. However, studies to prove pharmacological activities are scarce, and require chemical-biological standardization. Furthermore, correct botanical classification needs to be included in publications to simplify data acquisition. Finally, more in-depth phytochemical studies, allowing the linking of traditional use to pharmacological relevance are needed to be done in a standardized way.

Comparative assessment of nutritional composition, polyphenol profile and antioxidative properties of wild edible ferns from northeastern China.

Ferns are one of the prevalent species of wild edible plants but one of the least explored terrestrial plants. Therefore, the aim of this study was to assess the nutrient composition, polyphenol profile and antioxidative properties of four wild edible ferns commonly utilized in northeastern China. We studied the content of ash, polysaccharide, protein, fat and mineral elements of the samples. Furthermore, the samples were found to have good total phenolic and total flavonoid contents and some level of antioxidant capacity as determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline) 6-sufonic acid (ABTS) and ferric reducing antioxidant power (FRAP). They also exhibited different specific accumulation of polyphenol profiles, estimated by liquid chromatography/mass spectrometry (LC/MS). Significance analysis revealed a significant correlation between individual phenolic compounds and the antioxidant activity of the ferns. The results of the study suggest that wild edible ferns are rich in nutritional value and have potential as a natural source of antioxidants.

Ancient Food Habits Dictate that Food Can Be Medicine but Medicine Cannot Be "Food"!!

Background: Extensive surveys of several population settlements in different parts of India-covering plains, mountains, valleys, river banks and deeper areas of forests at different altitudes-between 1968 and 2016 demonstrated that the basic vital need of hunger is being fulfilled since antiquity by plants in the wild. Methods: Based on collections, consultations with local population personnel and literature searches, this paper presents many plants that are commonly used as food and focuses on their products, which are rich in alkaloids, polysaccharides, steroids, terpenoids, flavonoids, aminoacids, fatty acids and antibiotics etc. These complex organic compounds are suitable for the production of drugs for many ailments/diseases, including the prevention of cancers. Results: There are more than 100 families including several hundred plant taxa from various plant groups like angiosperms, bryophytes, pteridophytes, gymnosperms and even fleshy fungi, which have offered essential food items to ever-growing human populations since antiquity. Phytochemicals functioning as antioxidants are exceedingly beneficial to the human body but excess consumption of these compounds, adding higher levels of antioxidants, may even be responsible for chronic diseases including aging, cancer, cardiovascular diseases, rheumatoid arthritis, atherosclerosis, etc. These medicines can obviously be taken in small and prescribed quantities but can never be consumed as "food items."