## 3 _Nelumbo nucifera_
### Antioxidant Health Promoting Effect of Nelumbo uncifera Bioactives and Extracts
#### 3.2.1 In Vitro Antioxidant Effects of Nelumbo uncifera's Bioactives and Extracts
It involves the reduction of the Folin-Ciocalteu reagent by phenolic compounds, leading to a color change that can be quantified spectrophotometrically. High antioxidant activity by the test of DPPH free radical scavenging activity was also observed [34]. Lotus seeds were roasted until browned, and extract with hot water was consumed by rats for a long period of time to observe the protective effects on skin against photoaging due to UVB irradiation. After 8 months, there was a significant increase in the moisture content in the Lotus Seed Tea (LST) group rather than the water-control group. LST intake has been shown to inhibit the drying of the skin, which is caused by UV radiation to a certain degree [35]. Similar results were presented in the in vitro study of [PERSON] et al., where Lotus root flour was added to biscuits as a fat mimetic. In this research, different concentrations of lotus root flour (LRF) were added to wheat flour as a fat mimetic to have sample flours of varying wheat-to-LRF ratios. The biscuits had an increase in their total phenolic content, DPPH inhibition and FRAP as compared to the control sample, and it was concluded that wheat flour replacement with LRF in wheat-based food products will improve consumers' health benefits [36]. Several in vitro studies utilised the DPPH radical scavenging activity method to evaluate the antioxidant properties of various Nelumbo part extracts. More specifically, various extracts from Lotus Seeds (LS) and Seedpods (LSP) were tested, including fractions obtained using 80% ethanol, hexane, chloroform, ethyl acetate, butanol and water [37]. Additionally, [PERSON] et al. examined _N. uncifera_ seeds hydroalcoholic extract [38]; [PERSON] et al., lotus root ethanol extract [39]; [PERSON] et al., 50% and 70% ethanol extracts of lotus root and lotus leaf [40]; [PERSON] et al., methanol extracts of lotus plumule and blossom [41] and [PERSON] et al., ethanol or methanol extracts of lotus leaf [42]. Results consistently demonstrated high antioxidant activity across the different extracts. For instance, [PERSON] et al. compared the DPPH radical scavenging activity of lotus root extract with ascorbic acid, showing that the lotus root extract exhibited free radical scavenging properties, albeit with slightly lower potency than vitamin C [39]. [PERSON] et al. assessed the nitric oxide radical inhibition assay in addition to the DPPH method, revealing strong antioxidant properties of the extract comparable to ruitin, a standard antioxidant [38]. [PERSON] and [PERSON] employed different antioxidant assays, such as ABTS and FRAP, alongside the DPPH method. The findings indicated that the ethyl acetate fraction of LS exhibited the greatest activity in DPPH, ABTS and FRAP assays. On the other hand, water and ethanol fractions of LSP demonstrated the highest activity in DPPH and ABTS assays (water), as well as in the FRAP assay (ethanol) [37]. Furthermore, [PERSON] et al. evaluated various ethanol concentrations and chelating activity. They found that the 50% ethanol extract from lotus roots showed increased scavenging activity against DPPH radicals compared to the 75% ethanol extract. Additionally, the 50% ethanol root extract exhibited higher chelating activities than the leaf extracts; this enhanced activity was attributed to the superior chelating capacity of tannins found in lotus roots [40]. [PERSON] et al. evaluated the total flavonoid content and SOD-like activity in addition to DPPH and concluded that the methanolic extract of lotus leaves exhibited the best activities due to their phenolic content [42]. The Superoxide Dismutase (SOD) activity assay measures the enzyme's ability to catalyze the dismutation of superoxide radicals. It provides information on the antioxidant enzyme's capacity to neutralise superoxide radicals. In another study, [PERSON] et al. performed various antioxidant assays, including ferrous ion chelating ability, antioxidant activity in a haemoglobin-induced linoleic acid system, scavenging of hydroxyl radicals, and plasmid relaxation assay.