Stinging Nettle (Urtica dioica L.): Nutritional Composition, Bioactive Compounds, and Food Functional Properties.

Stinging nettle (Urtica dioica L., Urticaceae) is commonly found in Asia, Africa, and Europe and has a long history of being used as food and traditional medicine. Recently, this plant is gaining attention as a highly nutritious food, where fresh leaves are dried and used as powder or in other forms. Leaves are rich in many bioactive compounds. This review aims to cover the traditional uses in food and medicine, as well as its nutritional composition, including its bioactive chemical constituents and reported food functional activities. Various bioactive chemical constituents have been isolated from stinging nettle to date, such as flavonoids, phenolic acids, amino acid, carotenoids, and fatty acids. Stinging nettle extracts and its compounds, such as rutin, kaempferol, and vitamin A, are also used for their nutritional properties and as anti-inflammatory and antioxidant agents. Future studies should focus on the proper formulation and stability testing of the functional foods containing stinging nettle and their detailed activities in clinical studies.

Genus Blepharis (Acanthaceae): A review of ethnomedicinally used species, and their phytochemistry and pharmacological activities.

ETHNOPHARMACOLOGICAL RELEVANCE: Blepharis is an Afro-Asiatic genus belonging to the family Acanthaceae. It comprises about 126 species that occur in arid and semi-arid habitats. Some species of Blepharis are used in traditional medicines in different countries mainly for their anti-inflammatory, wound healing activities along with treatment of gastrointestinal disorders and bone fractures. AIM OF THE REVIEW: The present review aims to collate and analyze the available data and information on distribution, traditional uses, chemical constituents and pharmacological activities of Blepharis. METHODS: Scientific information of genus Blepharis was retrieved from the online bibliographic databases such as MEDLINE/PubMed, SciFinder, Web of Science and Google Scholar and secondary resources including books and proceedings. RESULTS: Seven species of Blepharis were found to be reported frequently as useful in folklore in African and Asian countries. B. maderaspatensis was found to be widely used in Indian traditional medicines whereas the B. ciliaris and B. edulis were common in folklore of Egypt, Jordan, and Arabia. Active phytochemicals of Blepharis are flavonoids from B. ciliaris, alkaloids from B. sindica, phenolic acid derivatives, and phytosterols, and derivatives of hydroxamic acids from B. edulis resulted in possessing diverse biological properties such as anti-microbial, anti-inflammatory, and anti-cancer. CONCLUSIONS: Various species of Blepharis were found to be used in traditional medicine systems in African and Asian countries. Few of these species were studied for their bioactive chemical constituents however the activity guided isolation studies are not performed. Similarly, detailed pharmacological studies in animal models to explore their mechanism of action are also not reported. Future studies should focus on these aspects related to the medicinally used species of Blepharis. The detailed and comprehensive comparative analysis presented here gives valuable information of the currently used Blepharis species and pave the way to investigate other useful species of Blepharis pertaining to ethnobotany, phytochemistry and discovery of new drugs.

Fruits of Terminalia chebula Retz.: A review on traditional uses, bioactive chemical constituents and pharmacological activities.

Fruits of Terminalia chebula Retz. (Combretaceae) are widely used as crude drugs in various traditional medicine systems. The aim of this article is to review the available scientific information regarding the traditional uses, bioactive chemical constituents and the pharmacological activities of T. chebula. Numerous researches conducted on T. chebula have confirmed the presence of wide range of the phytochemicals such as flavonoids, tannins, phenolic acids and other bioactive compounds. T. chebula is also widely studied regarding its pharmacological activities such as antioxidant, hepatoprotective, neuroprotective, cytotoxic, antidiabetic, anti-inflammatory activities among others. However, more in vivo and clinical studies for mechanism-based pharmacological evaluation should be conducted in future to provide stronger scientific evidences for their traditional uses.

Anti-neuroinflammatory activities of extract and polymethoxyflavonoids from immature fruit peels of Citrus 'Hebesu'.

Chronic neuroinflammation is reported to be associated in the progression of many neurodegenerative diseases and there is an increasing interest for the natural products as neuroprotective and anti-neuroinflammatory agents. In present research, we evaluated the potential inhibitory effects of extract, fractions, and isolated compounds from Citrus 'Hebesu' on lipopolysaccharide (LPS)-induced inflammatory responses using BV-2 murine microglial cells. The dried methanol extract (CH) was suspended in water and partitioned with hexane and ethyl acetate to give hexane soluble (CHH), ethyl acetate soluble (CHE), and water soluble (CHW) fractions. The extract (CH) and fractions CHH and CHE inhibited the expression of mRNA encoding pro-inflammatory cytokine interleukin (IL)-1ß. CHE and CHH were further purified by various column chromatographic methods to obtain hesperidin (1), tangeretin (2), 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone (3), 3,5,6,7,8,3',4'-heptamethoxyflavone (4), nobiletin (5), 3,4,5-trimethoxy-trans-cinnamic alcohol (6), and meranzin hydrate (7). Among them, three polymethoxyflavonoids, 3, 4, and 5 significantly inhibited the expression of IL-1ß mRNA. PRACTICAL APPLICATIONS: Citrus 'Hebesu' is a local cultivar in Hyuga City, Miyazaki prefecture, Japan and its immature fruits are consumed with different food recipes. Till now, there is no detailed study on the chemical constituents and anti-neuroinflammatory activity of this cultivar. In this study, seven compounds were isolated from the peels of immature fruits. Methanol extract, hexane, and ethyl acetate fractions and three polymethoxyflavonoids showed a significant inhibitory activity against expression of IL-1ß mRNA. Consumption of peels of Citrus 'Hebesu' might play important role in the prevention and treatment of neurodegenerative diseases, however, detailed mechanism based in vivo studies are necessary in future for providing more scientific evidences.

Chemical constituents from the flowers of Satsuma mandarin and their free radical scavenging and α-glucosidase inhibitory activities.

Flowers of Citrus plants are used as mild sedatives and for the treatment of insomnia in traditional medicines. In Japan, tea made from the flowers of Satsuma mandarin is consumed as healthy drink. Hesperidin (1), hesperetin (2), rutin (3), quercetin (4), nicotiflorin (5), eriocitrin (6), narirutin (7), phenylethyl glucoside (8) and unshuoside A (9) were isolated from the MeOH extract of fresh flowers. Structure elucidation of these compounds was performed on the basis of NMR spectroscopic data. Among them, rutin (3), quercetin (4) and eriocitrin (6) showed potent free radical scavenging activity, whereas hesperetin (2) and quercetin (4) showed potent α-glucosidase inhibitory activity.