Betalains are naturally occurring pigments sourced mainly from Beta vulgaris (beetroot), Hylocereus spp. (dragon fruit), Amaranthus spp., and Opuntia spp. Betalains are widely used for their vibrant colors and health-promoting properties. These nitrogenous, water-soluble pigments are crucial colorants in the food industry, responsible for the red, purple, and yellow plant tissues, predominantly in the order Caryophyllales. They are grouped into betacyanins, with reddish-violet hues, and betaxanthins, yellow to orange. Examples include beetroot stems for betacyanins and yellow pitaya pulp for betaxanthins. Several pharmacological activities were reviewed in the scientific literature, describing their potential implications for human health. In this review, we focused on the main and latest studies on the pharmacological effects and mechanisms of betalains, including antioxidant, anti-inflammatory, antihypertensive, hypolipidemic, antidiabetic, hepatoprotective, neuroprotective, anticancer, and antimicrobial properties, in both in vitro and in vivo studies. Overall, betalain consumption is considered safe, with no major adverse effects or allergic reactions reported. We also approached topics such as the pharmacokinetics, bioavailability, stability, and enhanced stabilization of betalains. This article provides a comprehensive overview of bioactive potential of betalains, highlighting the biochemical mechanisms involved. The current knowledge broadens the clinical applicability of betalains, making them potential sources of nutraceutical compounds that can be used to develop functional foods.
