450
21.3.2 S-Allyl Cysteine
S-allyl cysteine (SAC) derived from garlic was found to significantly reduce the
level of blood glucose in rats (Saravanan et al. 2009). The hypoglycemic effect of
SAC was attributed to the sulfur compound by stimulating directly or indirectly the
insulin secretion (Carson 1987; Augusti and Sheela 1996). Moreover, it was also
suggested that this compound improves the utilization of glucose thus significantly
decreasing blood glucose levels (Saravanan et al. 2009). SAC is also attributed to be
responsible for activating the synthesis of thyroid hormones circulating in the blood
which is responsible for triggering the synthesis of insulin (Saravanan and
Ponmurugan 2012).
21.3.3 Sulforaphane
Sulforaphane from broccoli sprouts was also noted to prevent diabetes-induced
fibrosis and to be an effective supplementary treatment for diabetes and its complications (Bahadoran et al. 2013). SMCS isolated from onions were also reported to
possess an anti-hyperglycemic effect by stimulating utilization of glucose and production of other antioxidant enzymes (Kumari and Augusti 2002). Similar results
were also observed in alloxan-induced diabetic rats where SMCS possessed hypoglycemic effects by triggering insulin secretion (El-Demerdash et al. 2005).
21.3.4 Cysteine
Cysteine is a sulfur-containing amino acid in plants that is present in the conjugated
forms such as S-allyl cysteine, S-allyl mercaptocysteine, N-acetyl cysteine and
S-ethyl cysteine (Poojary et al. 2017). Among conjugated cysteine forms, S-allyl
cysteine is found in plants of Allium species such as onions (Allium cepa L.), garlic
(Allium sativum L.), shallots (Allium ascalonicum), leeks (Allium ampeloprasum
L.) and chives (Allium schoenoprasumand L.). Recently, it was stated that S-allyl
cysteine was responsible for the anti-diabetic property of onions by stimulating the
secretion of insulin from the pancreatic β-cells (Sabiu et al. 2019). Also, it has been
reported in various literatures that S-methyl cysteine sulfoxide is accountable for
the anti-hyperglycemic and antioxidant activity of onions (El-Demerdash et al.
2005; Kumari and Augusti 2002; Tamura et al. 2007). Likewise, S-methylcysteine
sulfoxide was proven to stimulate the secretion of insulin (Augusti and Sheela
1996), while S-allylcysteine exhibited anti-diabetic effect via amelioration of free
radicals and pro-oxidant species as well as stimulation of Nrf2 factors (ColínGonzález et al. 2012).
A. M. P. Walag et al.
21.3.2 S-Allyl Cysteine
S-allyl cysteine (SAC) derived from garlic was found to significantly reduce the
level of blood glucose in rats (Saravanan et al. 2009). The hypoglycemic effect of
SAC was attributed to the sulfur compound by stimulating directly or indirectly the
insulin secretion (Carson 1987; Augusti and Sheela 1996). Moreover, it was also
suggested that this compound improves the utilization of glucose thus significantly
decreasing blood glucose levels (Saravanan et al. 2009). SAC is also attributed to be
responsible for activating the synthesis of thyroid hormones circulating in the blood
which is responsible for triggering the synthesis of insulin (Saravanan and
Ponmurugan 2012).
21.3.3 Sulforaphane
Sulforaphane from broccoli sprouts was also noted to prevent diabetes-induced
fibrosis and to be an effective supplementary treatment for diabetes and its complications (Bahadoran et al. 2013). SMCS isolated from onions were also reported to
possess an anti-hyperglycemic effect by stimulating utilization of glucose and production of other antioxidant enzymes (Kumari and Augusti 2002). Similar results
were also observed in alloxan-induced diabetic rats where SMCS possessed hypoglycemic effects by triggering insulin secretion (El-Demerdash et al. 2005).
21.3.4 Cysteine
Cysteine is a sulfur-containing amino acid in plants that is present in the conjugated
forms such as S-allyl cysteine, S-allyl mercaptocysteine, N-acetyl cysteine and
S-ethyl cysteine (Poojary et al. 2017). Among conjugated cysteine forms, S-allyl
cysteine is found in plants of Allium species such as onions (Allium cepa L.), garlic
(Allium sativum L.), shallots (Allium ascalonicum), leeks (Allium ampeloprasum
L.) and chives (Allium schoenoprasumand L.). Recently, it was stated that S-allyl
cysteine was responsible for the anti-diabetic property of onions by stimulating the
secretion of insulin from the pancreatic β-cells (Sabiu et al. 2019). Also, it has been
reported in various literatures that S-methyl cysteine sulfoxide is accountable for
the anti-hyperglycemic and antioxidant activity of onions (El-Demerdash et al.
2005; Kumari and Augusti 2002; Tamura et al. 2007). Likewise, S-methylcysteine
sulfoxide was proven to stimulate the secretion of insulin (Augusti and Sheela
1996), while S-allylcysteine exhibited anti-diabetic effect via amelioration of free
radicals and pro-oxidant species as well as stimulation of Nrf2 factors (ColínGonzález et al. 2012).
A. M. P. Walag et al.