fa Herbal Drugs كاربردي Review/Systemtic review <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><b>Objective:</b> Ultraviolet (UV) radiation, a component of the solar electromagnetic spectrum, functions both as an environmental stressor and a biological stimulus. Medicinal plants exposed to UV particularly UV-B and UV-C wavelengths often show enhanced synthesis of secondary metabolites, including flavonoids, phenolic compounds, alkaloids, and terpenoids. These metabolites are well recognized for their antioxidant, anti-inflammatory, anticancer, and antibacterial properties. This review aims to examine the effects of different UV wavelengths and doses on the chemical composition and therapeutic potential of medicinal plants.<br> <b>Methodology:</b> A comprehensive literature survey from 2000 to 2025 was conducted, covering diverse plant species and genotypes exposed to UVA, UVB, or UVC radiation, alone or in combination with environmental factors such as drought stress or hormonal treatments. Key parameters analyzed included growth characteristics, photosynthetic activity, phenolic and antioxidant content, and alkaloid production.<br> <b>Results:</b> Controlled UV exposure was found to significantly enhance secondary metabolite accumulation, increase antioxidant activity, and improve the pharmacological properties of medicinal plants. In contrast, excessive UV exposure could impair growth and induce cellular damage. The combination of UV with hormonal treatments or salicylic acid frequently upregulated gene expression in metabolic pathways associated with bioactive compound synthesis. The intensity, duration, and wavelength of UV radiation were critical determinants of chemical composition and biological activity.<br> <b>Conclusion:</b> Appropriately timed and dosed UV radiation represents a promising strategy to augment secondary metabolite production and enhance the therapeutic value of medicinal plants. These findings have important implications for optimizing cultivation practices and developing effective plant-based pharmaceuticals.<br> <br> <span minion="" pro=""><span style="color:black"><img alt="" src="./files/site1/images/copuediting.png" style="width: 586px; height: 265px;" ></span></span></span></span></div> Ultraviolet (UV) radiation, medicinal plants, secondary metabolites, flavonoids, phenolic compounds, antioxidants, alkaloids 0 0 http://pbp.medilam.ac.ir/browse.php?a_code=A-10-25-79&slc_lang=fa&sid=1 Emir Soltanbeigi emir.soltanbeigi@afsu.edu.tr 10031947532846005879 10031947532846005879 No Department of Medicinal and Aromatic Plants, Atatürk Health Care Vocational School, Afyonkarahisar Health Sciences University, Afyonkarahisar, Turkey Roman Lysiuk pharmacognosy.org.ua@ukr.net 10031947532846005880 10031947532846005880 Yes Department of Pharmacognosy and Botany, Danylo Halytsky Lviv National Medical University, Pekarska,69., Lviv, Ukraine