# The Role of Beetroot Ingredients in the Prevention of Alzheimer's Disease
## 4 Saponins  
Saponins are a group of chemical compounds found in a variety of plant species. They share a precursor composed of 30 carbon atoms (oxidosqualene). Chemically, they are classified as glycosides. They comprise two parts. Aglycone or the non-sugar part, and glycan--the sugar part. Depending on the character of the aglycone, two classes of saponins are distinguished: triterpen saponins and steroid saponins [68]. The presence of bioactive triterpen aponins was reported in beetroot, with oleanolic acid and its derivatives constituting the non-sugar part. For instance, [PERSON] et al. [69] isolated betavulgarosides I-VIII. [PERSON] et al. [70] analyzed the biochemical composition of several beet cultivars. They identified 44 saponins ([PERSON] cultivar). The respective aglycones included oleanolic acid, hederagenin, akebonoic acid, and gypogenin. In most cases, the non-sugar part was composed of oleanolic acid. Triterpenoid saponins contain one or two sugar radicals bonded with the aglycone by a glycoside bond. The sugar part is usually composed of hexoses, pentoses, 6-deoxyhexoses, and uronic acids. Swenty-seven saponin derivatives of the same have been identified. The remaining saponins were derivatives of akebonnic acid (10 saponins), hederagenin (6 saponins), and gypsogenin (1 saponin). In another paper, [PERSON] et al. [71] confirmed the presence of 44 saponins in beetroot, as well as the presence of betavulgarosides I-VIII, which were also reported by [PERSON] et al. [68]. [PERSON] et al. [72] analyzed extracts from beet leaves and identified 11 saponins with oleanolic acid constituting the aglycone and hexoses, pentoses, and uronic acid as the glycan. The research team quantitatively measured the content of saponins in extracts from the leaves and roots of four beet cultivars--Red Spher, Forono, Egyptian, and Round Dark Red. The content of saponins in the leaf extract was between 5905.6 ug/g of dry matter in Forono and 11,555.9 ug/g d.m. in Red Sphere plants. The content of saponins in beetroot extracts was between 4109.7 ug/g d.m. (Forono) and 16,363.4 ug/g d.m. (Egyptian).  
In plants, saponins provide protection against pathogens. Moreover, due to their biological activity, they show anti-inflammatory, antibacterial, anticancer, immunomodulatory, and antiparasitic properties [72]. Unfortunately, no scientific reports are available regarding the use of beetroot saponins in the treatment of neurodegenerative diseases. Nonetheless, attempts have been made to use saponins obtained from other plants in the prevention of such diseases. For instance, [PERSON] et al. [73] analyzed the therapeutic effect of saponins in AD. Saponins were extracted from the seeds of fenugreek (_T. foenum-gracum_ L). A methanol extract was used in the study conducted on rats with induced AD (drinking water containing aluminum chloride (III) (0.3%) for 45 days). The therapeutic dose consisted of a methanol extract from fenugreek seeds (0.05, 0.1, and 2% in drinking water for 45 days). A decrease in the activity of acetylcholinesterase-intercalase, a key enzyme in the etiology of AD, was observed. The AChE inhibitive activity was expressed in the form of the IC50 index. The value of IC50 for the control group receiving only water was 8.2 \(\pm\) 2.3 \(\upmu\)g/mL. For the AD group receiving only AlCl\({}_{3}\), it was 13.6 \(\pm\) 3.2 \(\upmu\)g/mL. The value of IC50 for the study group receiving 0.05, 0.1, and 2% of the methanol saponin extract was, respectively, 36.2 \(\pm\) 7.6, 64.1 \(\pm\) 9.2, and 85.6 \(\pm\) 8.4 \(\upmu\)g/mL. On average, the value of inhibitive activity index increased 4.5, 8, and 10.6-fold in the cerebral tissue of rats, relative to the control group receiving only water. By comparison, in the group receiving the reference drug--rivastigmine (0.3 mg/kg b.w. in drinking water for 45 days), the IC50 index was 62.3 \(\pm\) 7.7 \(\upmu\)g/mL.