Chemopreventive Action of Xanthone Derivatives on Photosensitized DNA Damage¶

Evaluation of the Antidiabetic Potential of Xanthone-Rich Extracts from Gentiana dinarica and Gentiana utriculosa

Despite the existence of various therapeutic approaches, diabetes mellitus and its complications have been an increasing burden of mortality and disability globally. Hence, it is necessary to evaluate the efficacy and safety of medicinal plants to support existing drugs in treating diabetes. Xanthones, the main secondary metabolites found in Gentiana dinarica and Gentiana utriculosa, display various biological activities. In in vitro cultured and particularly in genetically transformed G. dinarica and G. utriculosa roots, there is a higher content of xanthones. The aim of this study was to investigate and compare antidiabetic properties of secondary metabolites (extracts) prepared from these two Gentiana species, cultured in vitro and genetically transformed with those collected from nature. We compare HPLC secondary metabolite profiles and the content of the main extract compounds of G. dinarica and G. utriculosa methanol extracts with their ability to scavenge DPPH free radicals and inhibit intestinal α-glucosidase in vitro. Anti-hyperglycemic activity of selected extracts was tested further in vivo on glucose-loaded Wistar rats. Our findings reveal that the most prominent radical scavenging potential and potential to control the rise in glucose level, detected in xanthone-rich extracts, were in direct correlation with an accumulation of xanthones norswertianin and norswertianin-1-O-primeveroside in G. dinarica and decussatin and decussatin-1-O-primeveroside in G. utriculosa.

A Review of Swertia chirayita (Gentianaceae) as a Traditional Medicinal Plant

Swertia chirayita (Gentianaceae), a popular medicinal herb indigenous to the temperate Himalayas is used in traditional medicine to treat numerous ailments such as liver disorders, malaria, and diabetes and are reported to have a wide spectrum of pharmacological properties. Its medicinal usage is well-documented in Indian pharmaceutical codex, the British, and the American pharmacopeias and in different traditional medicine such as the Ayurveda, Unani, Siddha, and other conventional medical systems. This ethnomedicinal herb is known mostly for its bitter taste caused by the presence of different bioactive compounds that are directly associated with human health welfare. The increasing high usage of Swertia chirayita, mostly the underground tissues, as well as the illegal overharvesting combined with habitat destruction resulted in a drastic reduction of its populations and has brought this plant to the verge of extinction. The increasing national and international demand for Swertia chirayita has led to unscrupulous collection from the wild and adulteration of supplies. The aim of this review is to provide a synthesis of the current state of scientific knowledge on the medicinal uses, phytochemistry, pharmacological activities, safety evaluation as well as the potential role of plant biotechnology in the conservation of Swertia chirayita and to highlight its future prospects. Pharmacological data reported in literature suggest that Swertia chirayita shows a beneficial effect in the treatment of several ailments. However, there is lack of adequate information on the safety evaluation of the plant. The pharmacological usefulness of Swertia chirayita requires the need for conservation-friendly approaches in its utilization. Providing high-quality genetically uniform clones for sustainable use and thereby saving the genetic diversity of this species in nature is important. In this regard, plant biotechnological applications such as micropropagation, synthetic seed production, and hairy root technology can play a significant role in a holistic conservation strategy. In addition to micropropagation, storage of these valuable genetic resources is equally important for germplasm preservation. However, more advanced research is warranted to determine the activities of bioactive compounds in vitro and in vivo, establish their underlying mechanisms of action and commence the process of clinical research.