Antioxidant and antidiabetic effects of gallic and protocatechuic acids: a structure–function perspective

Modulation of some markers of erectile dysfunction and malonaldehyde levels in isolated rat penile tissue with unripe and ripe plantain peels: identification of the constituents of the plants using HPLC

“…These distinguishing structural features confer antioxidant and pharmacological importance on them (Agarwal et al 2006;Adefegha et al 2015). Several reports have shown that phenolic components possess PDE-5, arginase, AChE and ACE inhibitory potentials which could be linked to the formation of hydrogen bond and hydrophobic interactions between these polyphenolic compounds and the hydrophobic active site of the enzymes (Dos-Reis et al 2013;Oboh et al 2015;Akomolafe et al 2016), and this could be responsible for the biological effects exhibited by the studied plantain peel extracts.…”

“…Hence, improving body antioxidant status could be helpful in combating oxidative damage, and one practical way is to improve/increase the consumption of phenolic-rich foods, as studies have shown in both in vitro and in vivo experimental models that the antioxidant property of plant foods is a function of their phenolics content (Shodehinde et al 2015;Adefegha et al 2015). Furthermore, the reducing power (ability to reduce Fe 3þ to Fe 2þ ) of the extracts is a function of their antioxidants capacity, which indicates their potential to prevent the production of oxidized intermediates of lipid peroxidation possibly via electron donation (Adefegha et al 2015). Nevertheless, it is worth mentioning that UPP had higher antioxidant properties compared with RPP, and this could be associated with its high phenolic content/constituents.…”

“…Phenolics are prominent class of phytochemicals due to their ability to donate electrons and terminate the chain reaction process as a result of their (poly) hydroxyl groups, most especially the 3 0 OH and 4 0 OH of their three-carbon chain (Adefegha et al 2015). These distinguishing structural features confer antioxidant and pharmacological importance on them (Agarwal et al 2006;Adefegha et al 2015).…”

“…The supernatant was used as a source of arginase, in which the activity was determined using Adefegha et al (2015) method in a reaction mixture containing Tris-HCl buffer (1.0 mM, pH 9.5, 1.0 mM MnCl), 0.1 M arginine solution and extract/L-2-amino-[4-(2 0 -hydroxyguanidino)] butyric acid (L-NOHA). The mixture was made to a final volume of 1.0 mL.…”

“…The reaction between superoxide and NO forms a highly toxic radical such as peroxynitrite, which is capable of reducing the available NO required for penile erection (Khan et al 2001;Agarwal et al 2006). The use of antioxidants has been reported to ameliorate oxidative stress via scavenging of free radicals and chelation of transition metals (Adefegha et al 2015;Ademiluyi et al 2015). So far, polyphenols which are abundant in plant-based human diet such as fruits and vegetables have been reported to be efficient in the management of ED and other related diseases such as hypertension with little or no side effects (Ferreira et al 2006;Oboh et al 2015;Akomolafe et al 2016).…”