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Advisor(s)
Abstract(s)
Glycoalkaloids are characteristic secondary metabolites in plants of the Solanaceae
family. Although perceived as potentially toxic, these compounds display different
bioactivities and pharmacological efFects. The glycoalkaloid tomatine can be found in
green tomatoes and comprises a junction ofa-tomatine (A) and dehydrotomatine (B).
As shown in Figure l, dehydrotomatine difFers from a-tomatine by having a double
bond in the steroidal B ring of the aglycone; but both glycoalkaloids have the same
tetrasaccharide (lycotetraose) side chain. Therefore, while a-tomatine hás lycotetraose
bonded to the aglycone tomatidine, dehydrotomatine hás the side chain attached
to the aglycone tomatidenol. Up to 500 mg/kg of tomatine can be found in unripe
(green) tomatoes, leveis that decrease with ripening (approximately 5 mg/kg in ripe
red tomatoes) [l].
We revised the mechanisms of action of tomatine and their involvement in
human health [l]. Its bioactivity derives mainly from the capacity to inhibit
acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) and to complex with
membrane 3j8-hydroxy sterols. In inflammatory processes, the aglycone tomatidine is
able to reduce inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2)
expression through blocking nuclear factor kappa B (NF-KB) and c-Jun N-terminal
kinase (JNK) signalling in lipopolysaccharide-stimulated macrophages. In turn,
a-tomatine hás the ability to decrease the cholesterol and triglyceride leveis, enhance
tUe immune system, and inhibit the growth of diíFerent type of câncer cells. Several
in vitro and in vivo studies have been highlighting the pharmacological potential of
these compounds, which have high potential to be used in the development of new
anticancer drugs, among others.
Description
Keywords
Tomato glycoalkaloids
Pedagogical Context
Citation
Pinela, José; Oliveira, M.B.P.P.; Ferreira, Isabel C.F.R. (2018). Tomato glycoalkaloids as new drug candidates: an overview of mechanisms of action and clinicai applications. In XXIV Encontro Luso Galego de Química. Porto. ISBN 978-989-8124-24-1