gossypol strongly inhibited α-glucosidase on concentration dependent manner by
functioning as a competitive inhibitor. Gossypol activated the insulin receptor
substrate 1 (IRS-1)/protein kinase B (Akt) signaling pathways and increased uptake
of glucose through the translocation of glucose transporter 4 (GLUT4) into plasma
membrane in C2C12 myotubes. Consistent with the in vitro study, a higher dose of
gossypol (2.5 mg/kg
À1 ) dramatically decreased the postprandial blood glucose
levels associated with the upregulated expressions of GLUT4 and the IRS-1/Aktmediated signaling cascade in skeletal muscle of streptozotocin-induced diabetic
mouse. Further, gossypol treatment considerably boosted antioxidant enzyme
expression and mitigated gluconeogenesis in the liver (Alam et al. 2018).
3.6.4 Antitumor and Anti-cancer Activity
Gossypol, a complex polyphenol with a highly yellow-colored pigment is found in
the small intercellular pigment glands in seeds, roots, stems, and leaves of cotton. As
discussed earlier, it is a racemic mixture of two enantiomers, (+) and (À). Gossypol
is basically considered as a toxic compound. Conversely, recent investigations have
demonstrated that gossypol and related compounds have anti-cancer activities,
including breast cancer (Liu et al. 2002; Zhong et al. 2013), colon cancer (Chien
et al. 2012), pancreatic cancer (Thakur et al. 2012; Yuan et al. 2013), and prostate
cancer (Huang et al. 2009; Pang et al. 2011). These novel findings have generated
great interest in biomedical field to understand and investigate potential of gossypol
and related compounds. In a recent investigation, Cao et al. (2018) reported the anticancer activity of glanded cottonseeds in which they isolated ethanol extracts from
cottonseeds and investigated their effects on human cancer cells derived from breast
and pancreas followed by MTT assay for cell viability. Ethanol extracts from
glanded and glandless cottonseed kernels and gossypol notably decreased breast
cancer cell mitochondrial activity. On the other hand, ethanol extract from glanded
cottonseed kernel and gossypol also significantly decreased pancreas cancer cell
mitochondrial activity. Such fascinating outcomes propose anti-cancer effect of
gossypol from cottonseeds.
In a previous study, Ko et al. (2007) showed that gossypol exhibits potent
cytotoxic effects via apoptosis induction against human colorectal carcinoma cells.
Hence in further approach, they reported that addition of 12-Otetradecanoylphorbol-13-acetate (TPA) significantly inhibited GOS-induced apoptosis in human colorectal carcinoma HT-29 cells in accordance with inducing COX-2
protein/PGE(2) production (Chien et al. 2012). The results of one of the studies on
anti-cancer activity of gossypol showed that (À) gossypol was the major inhibitory
component of cancerous breast cell growth. The inhibitory activity of (À) gossypol
was associated with the reduction of the cell cycle regulator, cyclin D1, and the
induction of the cell proliferation inhibitor, TGFbeta (Liu et al. 2002). Another
findings illustrated that (À) gossypol reduced in vitro invasion of both the parental
3 Cottonseed (Gossypium hirsutum)
8 3
functioning as a competitive inhibitor. Gossypol activated the insulin receptor
substrate 1 (IRS-1)/protein kinase B (Akt) signaling pathways and increased uptake
of glucose through the translocation of glucose transporter 4 (GLUT4) into plasma
membrane in C2C12 myotubes. Consistent with the in vitro study, a higher dose of
gossypol (2.5 mg/kg
À1 ) dramatically decreased the postprandial blood glucose
levels associated with the upregulated expressions of GLUT4 and the IRS-1/Aktmediated signaling cascade in skeletal muscle of streptozotocin-induced diabetic
mouse. Further, gossypol treatment considerably boosted antioxidant enzyme
expression and mitigated gluconeogenesis in the liver (Alam et al. 2018).
3.6.4 Antitumor and Anti-cancer Activity
Gossypol, a complex polyphenol with a highly yellow-colored pigment is found in
the small intercellular pigment glands in seeds, roots, stems, and leaves of cotton. As
discussed earlier, it is a racemic mixture of two enantiomers, (+) and (À). Gossypol
is basically considered as a toxic compound. Conversely, recent investigations have
demonstrated that gossypol and related compounds have anti-cancer activities,
including breast cancer (Liu et al. 2002; Zhong et al. 2013), colon cancer (Chien
et al. 2012), pancreatic cancer (Thakur et al. 2012; Yuan et al. 2013), and prostate
cancer (Huang et al. 2009; Pang et al. 2011). These novel findings have generated
great interest in biomedical field to understand and investigate potential of gossypol
and related compounds. In a recent investigation, Cao et al. (2018) reported the anticancer activity of glanded cottonseeds in which they isolated ethanol extracts from
cottonseeds and investigated their effects on human cancer cells derived from breast
and pancreas followed by MTT assay for cell viability. Ethanol extracts from
glanded and glandless cottonseed kernels and gossypol notably decreased breast
cancer cell mitochondrial activity. On the other hand, ethanol extract from glanded
cottonseed kernel and gossypol also significantly decreased pancreas cancer cell
mitochondrial activity. Such fascinating outcomes propose anti-cancer effect of
gossypol from cottonseeds.
In a previous study, Ko et al. (2007) showed that gossypol exhibits potent
cytotoxic effects via apoptosis induction against human colorectal carcinoma cells.
Hence in further approach, they reported that addition of 12-Otetradecanoylphorbol-13-acetate (TPA) significantly inhibited GOS-induced apoptosis in human colorectal carcinoma HT-29 cells in accordance with inducing COX-2
protein/PGE(2) production (Chien et al. 2012). The results of one of the studies on
anti-cancer activity of gossypol showed that (À) gossypol was the major inhibitory
component of cancerous breast cell growth. The inhibitory activity of (À) gossypol
was associated with the reduction of the cell cycle regulator, cyclin D1, and the
induction of the cell proliferation inhibitor, TGFbeta (Liu et al. 2002). Another
findings illustrated that (À) gossypol reduced in vitro invasion of both the parental
3 Cottonseed (Gossypium hirsutum)
8 3