STINGING NETTLE (URTICA DIOICA) AS A SOURCE OF BIOLOGICALLY ACTIVE SUBSTANCES IN MEDICINE (Literature Review)

Аннотация

Stinging nettle (Urtica dioica) is a widely distributed medicinal plant with diverse pharmacological properties. Due to its rich chemical composition—including vitamins, minerals, flavonoids, and chlorophyll—it exhibits hemostatic, anti-inflammatory, diuretic, antianemic, immunostimulating, and hypoglycemic effects. In both traditional and official medicine, nettle is used for thetreatment of anemia, bleeding, joint diseases, skinconditions, and as part of complex therapy for diabetes mellitus. Various medicinal forms include decoctions, infusions, juice, extracts, and herbal preparations. Despite its high efficacy, the plant has a number of contraindications, which require caution in its use. This article summarizescurrent data onthepotential applications of stinging nettlein medical practice. Keywords: stinging nettle, Urtica dioica, medicinal plants, phytotherapy, hemostatic effect, anti-inflammatory effect, anemia, diabetes mellitus, biologically active substances, traditional medicine, vitamins,flavonoids. Introduction Stinging nettle (Urtica dioica) has traditionally been used in the folk medicine of many countries as a hemostatic, anti-inflammatory, diuretic, and tonic agent. In recent decades, interest in this plant has grown due to in-depth studies of its chemical composition and pharmacological properties [1, 4, 8]. Nettle is rich in vitamins (C, K, and B group), minerals (iron, calcium, zinc), flavonoids (rutin, quercetin), chlorophyll, and polysaccharides [2, 3, 14]. Its leaves also contain phenolic compounds and lignans, which contribute to its antioxidant and immunostimulatory activity [4, 7]. Extracts of Urtica dioica have been shown to reduce levels of pro-inflammatory cytokines such as TNF-α and IL-1β by inhibiting the nuclear factor NF-κB [4, 10]. Clinical trials have demonstrated the beneficial effects of nettle in the treatment of rheumatoid arthritis and osteoarthritis [11]. A 2021meta-analysis confirmed that nettlereduces blood glucose levels inpatients withtype 2 diabetes [6]. The mechanisms of action include stimulation of insulin secretion and increased tissue sensitivity to insulin [9]. The antioxidant effect of nettle is attributed to its high content of flavonoids and chlorophyll, which neutralize free radicals and reduce oxidative stress [1, 10, 18]. Nettle also stimulates erythropoiesis due to its high iron and vitamin C content, which is especially beneficial in anemia [14, 19]. Recent studies have demonstrated the effectiveness of nettle in the treatment and prevention of: – type 2 diabetes mellitus [6, 16, 20]; – inflammatory joint diseases [11]; – benign prostatic hyperplasia [5];– anemias [14, 19]; – skin and allergic conditions [3, 12]. Current research focuses on deciphering the molecular mechanisms of nettle’s effects. It has been established that phenolic compounds in the leaves inhibit the enzymes lipoxygenase and cyclooxygenase, resulting in reduced production of pro-inflammatory mediators such as prostaglandins [1, 4, 10]. Furthermore, Urtica dioica has demonstrated the ability to modulate alpha-glucosidase enzyme activity, thereby lowering postprandial blood sugar levels [6, 20]. This makes it a promising adjunct in the complex therapy of diabetes mellitus. At the molecular level, nettle 98,7:ROTCAFTCAPMI .SECNEICSLACIDEM ,5202, enuJ,5emuloV gro.srehsilbupcimedaca.www extract also enhances the expression ofantioxidant enzymes —superoxidedismutase(SOD), catalase, and glutathione peroxidase[7, 10]. This explains its ability to reduce oxidative stress observed in chronic inflammation, diabetes mellitus, and oncological conditions. A review of the literature has shown that Urtica dioica extracts can inhibit the growth of tumor cells in vitro, particularly prostate, breast, and gastric cancer cells [4, 12, 13]. Nettle flavonoids have been shown to induce apoptosis (programmed cell death) and inhibit the proliferation of tumor cells via caspase- dependent pathways [13]. Jahanban-Esfahlan et al. (2021) emphasize that nettle may serve as a promising basis for the development of anticancer phytotherapeutics, especially in combination with chemotherapeutic agents [4]. Nettle also exhibits significant antimicrobial activity against a wide range of microorganisms, including Staphylococcus aureus, Escherichia coli, Candida albicans, and Pseudomonas aeruginosa [12]. It has been shown that both aqueous and alcoholic extracts inhibit bacterial growth by disrupting the cell wall and inhibiting enzymatic systems [12, 15]. Studies have demonstrated that Urtica dioica extract enhances the immune response by increasing the activity of macrophages, T- lymphocytes, and natural killer (NK) cells [8]. According to Riehemann et al. (1999), nettle inhibits the release of pro-inflammatory cytokines in monocytes and reduces the expression of ICAM-1 — an adhesion molecule involved in inflammatory responses [4]. In addition, nettle polysaccharides activate the humoral arm of the immune system, p