Medicinal plants for diabetes associated neurodegenerative diseases: A systematic review of preclinical studies

Abstract

Diabetes mellitus is a metabolic defect with many complications for the patients. Deaths due to diabetes and its complications are increasing, and one of the most serious consequences are the neurological disorders. Chemical treatments have irreversible side effect and therefore the aim of this study is to evaluate the medicinal plants used for treatment of cognitive impairments and neurodegenerative diseases associated with diabetes in 2004–2020 period. Electronic databases used were PubMed, Scopus and Cochrane library. The keywords used were “diabetes,” “plant,” “herb,” “neurodegenerative,” “neurodegeneration,” “cognitive,” “cognition,” “Alzheimer,” “dementia.” The non‐English articles, repetitive articles and review studies were excluded. From total of 3,590 results, 58 articles are included in the study. The results show that many chemical treatments considered for this disease simply control hyperglycemia, but cannot improve the complications of diabetes. Herbal medicine could be more effective due to the high antioxidant activity of some medicinal plants. Biologically active substances of medicinal plants can improve the neurological disorders caused by diabetes via several pathways. The most important pathway is related to antioxidant properties. Other pathways include antiinflammatory, anti‐apoptotic, neurotoxicity inhibition, neuronal death, increasing the uptake of glucose by cells and improve neurotransmitters levels involved in learning and memory.

Hypolipidemic and Antioxidant Effects of Guishe Extract from Agave lechuguilla, a Mexican Plant with Biotechnological Potential, on Streptozotocin-Induced Diabetic Male Rats

“…Due to the latter, lipid control and careful monitoring are typically recommended [5]. Notwithstanding, not only do hyperglycemia and lipid alterations affect health conditions, but increased oxidative stress also causes impairment in physiological functions [6]. Oxidative stress could be mitigated by the main antioxidant enzymes in biological systems, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx).…”

“…Extracts from herbal medicines have been prepared and used, and their usefulness has been evaluated in experimental DM models in animals. In some plants, active hypoglycemic principles have been isolated and their mechanism of action studied, and most of them could be more effective due to their high antioxidant activity [6]. Agave lechuguilla Torrey (Asparagaceae) has been used in DM treatment [9]; however, the authors did not provide further information beyond mentioning its hypoglycemic effect without scientific evidence.…”

Antioxidant and Oxidant status of medicinal plant Echium italicum collected from different regions

“…Antioxidant defense system functions in reducing the effects of oxidative stress. In cases where the antioxidant defense system is insufficient, the use of supplemental antioxidants is very important (Mushtaq et al, 2020;Khazaei et al, 2021). Plants produce biologically active compounds with many medicinal properties.…”

Impact of High-Pressure Processing on Antioxidant Activity during Storage of Fruits and Fruit Products: A Review

“…Flavonoids are another group of phenolic compounds predominantly present in fruits and vegetables and known to possess strong anti-inflammatory activity [60]. They also play an important role to prevent certain diseases such as neurodegenerative processes [61] and metabolic disorders [62]. Although the oral bioavailability of flavonoids in some fruit products was relatively low, these compounds displayed a significant effect on the regulation of metabolism to ameliorate metabolic disorders.…”