Tocopherols in Ginkgo biloba L.: A comparative study between infusion and dietary suplements
Conference Paper
Overview
Overview
abstract
FCT for financial support to CIMO (PEst-OE/AGR/UI0690/2011) and L. Barros
(Compromisso para a Ciencia 2008).
The concentrated extracts of Ginkgo biloba leaves have been marketed in
Western countries as herbal medicines, which due to their bioactive compounds contribute for the improvement of cerebral blood flow and
memory [1]. One of those compounds is α-tocopherol, which intervenes in the
reduction of symptoms associated with oxidative stress in neurodegenerative
disorders, particularly Alzheimer's disease. α-Tocopherol, an isoform of the lipid
soluble vitamin E, is well-known as an antioxidant, and has been widely
investigated as a potential prophylactic dietary supplement in cardiovascular
diseases [2,3]. The objective of this study was to evaluate the amount and
profile of tocopherols in some dietary supplements: pills based on G. biloba
leaves standardized extract with 24% glycosides and 6% terpenes (P1, 40
mg/pill; P2, 60 mg/pill; and P3, 100 mg/pill); oral solution (OS- 40 mg of G.
bilobo standardized extract/mL); and compare them with the infusion of G.
bi/obo wild leaves (LI). Tocopherols were identified and quantified by high
performance liquid chromatography coupled to a fluorescence detector (H PLCfluorescence).
All the vitamers α-, β-, γ- and δ-tocopherol were found in the
infusion, but not in dietary supplements. Furthermore, the infusion gave the
highest amount of total tocopherols (126.23 mg/100 g dw) and of each
individual vitamer; α-tocopherol was, by far, the most abundant tocopherol in
that sample (124.88 mg/100 g dw). This study showed that wild G. bi/obo
infusion supplies a much higher amount of tocopherols than dietary
supplements based on the same plant. Moreover, its consumption could be
beneficial due to the capacity of α-tocopherol to eliminate reactive oxygen
species, inhibit lipid peroxidation, and attenuate inflammatory reactions.
