Plant Betalains: Safety, Antioxidant Activity, Clinical Efficacy, and Bioavailability

Abstract

Betalains are accepted food additives derived from vacuoles of plants belonging to about 17 families in the order Caryophyllales. These pigments are composed of a nitrogenous core structure, betalamic acid [4-(2-oxoethylidene)-1,2,3,4-tetrahydropyridine-2,6-dicarboxylic acid]. Betalamic acid condenses with imino compounds (cyclo-DOPA and/or its glucosyl derivatives) or amines and/or their derivatives to form violet betacyanins (for example, betanin) and yellow betaxanthins (for example, indicaxanthin), respectively. Till date, structures of 75 betalains have been elucidated from plants under the order Caryophyllales. The extracted betalains are safe to consume and they act as micronutrients in the body. In vitro studies to highlight radical-scavenging activity, cell culture studies to assess cytotoxicity and absorption of betalains, and proven clinical efficacies are compiled in this review. The literature on biological activity has not been analyzed for a synthesis of safety, clinical efficacy, and bioavailability to arrive at the concentrations required for the purported health benefits. Most betalains are under-utilized in pharmaceutical and cosmetic preparations due to poor stability and lack of scientific reports highlighting their superior tinctorial strength including flourescence, water solubility, and functional value alongside their bioavailability. This is the first comprehensive review on the dietary safety, biological activity and bioavailability of betalains. Based on this review, for future debate and input from health professionals, a human daily intake of betanin and indicaxanthin can be proposed at 100 and 50 mg, respectively.

Qualitative evaluation of fruits from different Opuntia ficus‐indica ecotypes/cultivars harvested in South Portugal

“…These results show that the capacity for scavenging free radicals is higher in the peel than in the pulp. This is in line to that observed by Serra et al (2013) (Butera et al, 2002;Cai, Sun, & Corke, 2003;Esatbeyoglu et al, 2014;Khan, 2016;Wybraniec et al, 2011).…”

“…Several components can be responsible for the results obtained in the present work, including the betalains. The antioxidant activity of betalains has been reported by several authors and was compiled in a recent review (Khan, ). Some authors (Gliszczýnska‐Świgło, Szymusiak, & Malinowska, ) have even demonstrated that betalains pigments possess higher activity than anthocyanins pigments.…”

“…Some authors (Gliszczýnska‐Świgło, Szymusiak, & Malinowska, ) have even demonstrated that betalains pigments possess higher activity than anthocyanins pigments. Several methods have been used for determining the antioxidant activity of betalains and simultaneously evaluate the power of the individual pigments (Butera et al, ; Cai, Sun, & Corke, ; Esatbeyoglu et al, ; Khan, ; Wybraniec et al, ). However, the different experimental procedures used by diverse authors led to inconsistent results.…”

A comprehensive review on beneficial dietary phytochemicals in common traditional Southern African leafy vegetables

“…Areal parts of A. cruentus and A. hybridus contained betacyanin of 40.4 and 6.4 mg amaranthin equivalent/100 g (FW) (Fresh Weight), respectively (Nana, Hilou, Millogo, & Nacoulma, ). Betacyanin is associated with numerous health benefits such as cytotoxic (Khan, ), neuroprotective (Wang & Yang, ), antidiabetic (Lugo‐Radillo, Delgado‐Enciso, & Pena‐Beltrãn, ), and hepatoprotective effects (Lee, Wettasinghe, Bolling, Ji, & Parkin, ).…”

“…Betacyanin is associated with numerous health benefits such as cytotoxic (Khan, 2016), neuroprotective (Wang & Yang, 2010), antidiabetic (Lugo-Radillo, Delgado-Enciso, & Pena-Beltrãn, 2012), and hepatoprotective effects (Lee, Wettasinghe, Bolling, Ji, & Parkin, 2005).…”