Aralia elata (Miq) Seem Extract Decreases O-GlcNAc Transferase Expression and Retinal Cell Death in Diabetic Mice

Research progress in pharmacological effects of Aralia elata

The traditional Chinese medicine Aralia elata (Miq.) Seem., also known as Aralia mandshurica, has the effect of "tonifying Qi and calming the mind, strengthening the essence and tonifying the kidneys, and dispelling wind and invigorating blood circulation". It is used in the treatment of neurasthenia, Yang deficiency and Qi deficiency, kidney Qi deficiency, spleen Yang deficiency, water-dampness stagnation, thirst, and bruises. Aralia elata saponins are the main components for the pharmacological effects. From the perspective of modern pharmacological science, Aralia elata has a wide range of effects, including anti-myocardial ischaemia and alleviation of secondary myocardium ischemic reperfusion injury by regulating ionic homeostasis, anti-tumor activity by inhibiting proliferation, promoting apoptosis and enhancing immunity, hypoglycemia and lipid lowering effects by regulating glucose and lipid metabolism, and hepato-protective, neuroprotective, anti-inflammatory/analgesic effects. The studies on pharmacological mechanisms of Aralia elata will be conducive to its development and application in the future. This article reviews the research progress of Aralia elata domestically and internationally in the last two decades and proposes new directions for further research.

Dihydroartemisinin ameliorates retinal vascular dysfunction in diabetes mellitus via the FASN/Kmal-mTOR/SREBP1 feedback loop

Microvascular dysfunction is the primary aetiology of visual impairment caused by diabetic retinopathy (DR). Dihydroartemisinin (DHA), the active metabolite of the antimalarials artemisinins, exhibits antiangiogenic properties in numerous diseases. Here, we investigated the function and mechanisms of DHA as a vasculoprotective agent in DR. DHA exerted its protective effect on vascular injuries in diabetic mice and inhibited cell proliferation and tube formation in human retinal microvascular endothelial cells by decreasing the level of fatty acid synthase (FASN), enhancing the malonylation of mechanistic target of rapamycin (mTOR) at lysine 1218 (K1218) and attenuating the activation of mTOR complex 1 (mTORC1). Impressively, a chemosynthetic small interfering RNA against FASN and mutagenesis of K1218 of mTOR showed therapeutic potential in suppressing cell proliferation and tube formation induced by high glucose. Notably, suppression of mTORC1 kinase activity further inhibited FASN by reducing p70S6K phosphorylation to subsequently reduce the expression of sterol regulatory element binding protein 1, which interacted directly with the FASN promoter at nucleotide positions -64 and -55. In conclusion, our study elucidated the promising effects of FASN and malonylation on vascular injuries of DR and indicated the great potential of DHA as a therapeutic approach.

The evaluation of anti-breast cancer activity and safety pharmacology of the ethanol extract of Aralia elata Seem. leaves

Aralia elata Seem. is a traditional folk Chinese medicinal plant and its leaves have been used to treat many diseases. We aimed to evaluate the anti-breast cancer activity and safety pharmacology of the ethanol extract of A. elata Seem. leaves (ELE). Cytotoxicity was evaluated on human tumor cell lines by MTT assay in vitro. A tumor bearing-nude mice model was used to assess antitumor activity in vivo. Cell apoptosis was determined by Hoechst 33258 staining, flow cytometry and TUNEL staining. The protein levels were determined by western-blotting and immunohistochemical staining. In safety evaluation, ICR mice and beagle dogs were orally administered ELE at different doses to determine its adverse effects on the central nervous system and cardiorespiratory system. ELE significantly inhibited tumor growth and induced cell apoptosis in MCF-7 cells in vitro and in vivo. The protein levels including caspase-3, caspase-9, bax, bcl-2, PARP, and cytochrome c were significantly changed. For the central nervous system, no treatment-related changes in behavior, motor activity or coordination were observed in mice. For the cardiorespiratory system, no significant differences in cardiorespiratory parameters including heart rate, PR interval, RR interval, P wave duration, QRS duration, QTcF interval, respiratory frequency, tidal volume, body temperature, and blood pressure were observed in beagle dogs between the ELE treatment and control group. In conclusion, ELE possessed anti-breast cancer activity by activating a mitochondrial-mediated apoptotic pathway with high biological safety in animals, which indicates it could be a potential therapeutic agent for treating human breast cancer in the future.

Diabetes and plant-derived natural products: From ethnopharmacological approaches to their potential for modern drug discovery and development

Diabetes is a disease of serious concern faced by the health care industry today. Primary diabetes mellitus and its complications are still costly to manage with modern drugs. Extensive research on the screening of anti-diabetic agents in past decades established natural products as one of the major potential sources of drug discovery. However, only a few drugs of plant origin have been scientifically validated. Therefore, the development of new anti-diabetic drugs is of great demand. Hence, natural products could be explored as potential anti-diabetic drugs. Natural plants derived extracts and molecules like berberine, ginsenosides, curcumin, stevioside, gingerols, capsaicin, catechins, simple phenolic compounds, anthocyanins, resveratrol, genistein and hesperidin obtained from different species are used for curing diabetes and found to possess different action mechanisms. In this review, the importance of medicinal plants and their active constituents for anti-diabetic agents are described. The present study also emphasized the importance of diabetes control, reduction in its complications and use of the anti-diabetic agents. The detailed action mechanism of these extracts/compounds for their activities are also described. However, the anti-diabetic drugs from plant origin require scientific validation through animal and clinical studies to exploit in terms of modern commercial medicines.