Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia, insulin dysfunction, and a substantial global health burden. Current pharmacological therapies often bring undesired side effects and limited long-term efficiency. These factors drive interest in the direction of preventive and complementary strategies. Plant-derived secondary metabolites – phenolics, alkaloids, terpenes, organosulfur compounds and polyacetylenes, demonstrate promising anti-diabetic activities. These compounds can modulate key molecular targets involved in glucose metabolism, insulin signaling, and development of oxidative stress, thereby improving glycemic control and reducing the risk of complications. Also, natural products can inhibit carbohydrate-digesting enzymes, enhance insulin secretion and sensitivity, regulate glucose transporters, and suppress pathways associated with inflammatory responses and the formation of advanced glycation end products (AGEs). Many of them also demonstrate pronounced antioxidant and antiglycative properties with all accompanying features - metal-chelating effects, α-dicarbonyl trapping properties, and interference with the AGE-RAGE axis, collectively mitigating vascular damage and attenuating diabetic complications such as nephropathy, neuropathy, and retinopathy. Recent studies highlight that certain plant metabolites can stabilize Nrf2, inhibit NF-κB activation, improve pancreatic β-cell function, and reduce protein tyrosine phosphatase activity. In this review we comprehensively address all this aspects with a special emphasis on the antiglycative properties as one of the central component of the overall anti-diabetic activity. Further, we discuss the further prospective in the biochemistry of plant-derived natural products in terms of antidiabetic, antiglycative and antioxidant agents. Although further research is needed to clarify their pharmacokinetics, safety, and efficacy in humans, the emerging evidence underscores the potential of plant secondary metabolites as natural, multifaceted agents for the prevention and management of diabetes and its associated complications.