only, whereas most of the studies have been conducted with GLA in addition to
omega-3-rich oils (aicosapentaenoic acid, EPA and docosahexaenoic acid, DHA)
(Chas et al. 2019; Wauquier et al. 2012; Camargo et al. 2018). The anticarcinogenic
activity of GLA could be attributed to the increased generation of reactive oxygen
species (ROS), accumulation of intracellular Ca
2+ , decrease in mitochondrial membrane potential and ATP level which further causes the dysfunctioning of mitochondrial membrane of tumour cells and upregulation of gene expression for antioxidant
proteins (Zhang et al. 2015; Tasset-Cuevas et al. 2013). Another possible reason
could be ascribed to the enhanced activation of caspases, which are cysteine–aspartic
proteases or a family of protease enzymes and essential for apoptosis (Zhang et al.
2015). Tasset-Cuevas et al. (2013) conducted an interesting study on the toxicity,
genotoxicity, antigenotoxicity and cytotoxicity effects of borage seed oil and GLA
individually. In the study, the life span of Drosophila melanogaster as affected by
low doses of GLA and borage seed oil was also evaluated. The results demonstrated
that borage seed oil and GLA both were DNA safe (non-genotoxic) and
antimutagenic. Borage oil was non-toxic to D. melanogaster at lower concentrations
(<125 μl/ml) and increased the health span portion !75% of the life span curves.
However, GLA did not show any positive effects on health span of D. melanogaster.
It should also be noted that borage seed oil and GLA both showed cytotoxic activity
at low doses (IC50 of 1 μl/ml and 0.087 mM, respectively) (Tasset-Cuevas et al.
2013). In another study, Jiang et al. (2000) studied the effect of GLA on breast
cancer cell lines (MCF-7 and MDA MB 231) and observed reduced growth of
cancerous cells due to decreased expression of peroxisome proliferator activator
receptors (PPARs). PPARs are key components of cellular responses to PUFAs.
Normally, cancerous cells express PPARs, particularly PPAR-γ. On interacting with
GLA, PPAR-γ gets phosphorylated and translocated from cytoplasm to nucleus, and
thus the growth of breast cancer cells is inhibited (Jiang et al. 2000). Zhang et al.
(2015) studied the effect of omega-3 fatty acids (ALA, EPA and DHA) and omega-6
fatty acids (GLA and AA) on colon cancer cells LoVo and RKO. In the study, it was
observed that all the PUFAs (at concentrations above 120 μM) significantly
supressed the growth of cancer cells probably through the inhibition of ATP
synthesis and dysfunctioning of mitochondria.
14.10.3 In Atopic Dermatitis (Eczema)
The GLA supplementation was first introduced to attenuate the signs and symptoms
of atopic dermatitis preceded by the oral dose of linoleic acid-rich oils (Sergeant
et al. 2016). Atopic dermatitis is a chronic inflammatory skin condition characterised
by red, itchy rashes normally on the cheeks, arms and legs. An estimated 10% of all
people worldwide are affected by atopic dermatitis at some point in their life
(National Eczema Association 2019). A growing literature has demonstrated the
beneficial effects of dietary GLA or GLA-rich oils on relieving the symptoms of
chronic dermatitis (Kawamura et al. 2011; Chung et al. 2002; Jung et al. 2014; Fujii
362
B. Tanwar et al.
omega-3-rich oils (aicosapentaenoic acid, EPA and docosahexaenoic acid, DHA)
(Chas et al. 2019; Wauquier et al. 2012; Camargo et al. 2018). The anticarcinogenic
activity of GLA could be attributed to the increased generation of reactive oxygen
species (ROS), accumulation of intracellular Ca
2+ , decrease in mitochondrial membrane potential and ATP level which further causes the dysfunctioning of mitochondrial membrane of tumour cells and upregulation of gene expression for antioxidant
proteins (Zhang et al. 2015; Tasset-Cuevas et al. 2013). Another possible reason
could be ascribed to the enhanced activation of caspases, which are cysteine–aspartic
proteases or a family of protease enzymes and essential for apoptosis (Zhang et al.
2015). Tasset-Cuevas et al. (2013) conducted an interesting study on the toxicity,
genotoxicity, antigenotoxicity and cytotoxicity effects of borage seed oil and GLA
individually. In the study, the life span of Drosophila melanogaster as affected by
low doses of GLA and borage seed oil was also evaluated. The results demonstrated
that borage seed oil and GLA both were DNA safe (non-genotoxic) and
antimutagenic. Borage oil was non-toxic to D. melanogaster at lower concentrations
(<125 μl/ml) and increased the health span portion !75% of the life span curves.
However, GLA did not show any positive effects on health span of D. melanogaster.
It should also be noted that borage seed oil and GLA both showed cytotoxic activity
at low doses (IC50 of 1 μl/ml and 0.087 mM, respectively) (Tasset-Cuevas et al.
2013). In another study, Jiang et al. (2000) studied the effect of GLA on breast
cancer cell lines (MCF-7 and MDA MB 231) and observed reduced growth of
cancerous cells due to decreased expression of peroxisome proliferator activator
receptors (PPARs). PPARs are key components of cellular responses to PUFAs.
Normally, cancerous cells express PPARs, particularly PPAR-γ. On interacting with
GLA, PPAR-γ gets phosphorylated and translocated from cytoplasm to nucleus, and
thus the growth of breast cancer cells is inhibited (Jiang et al. 2000). Zhang et al.
(2015) studied the effect of omega-3 fatty acids (ALA, EPA and DHA) and omega-6
fatty acids (GLA and AA) on colon cancer cells LoVo and RKO. In the study, it was
observed that all the PUFAs (at concentrations above 120 μM) significantly
supressed the growth of cancer cells probably through the inhibition of ATP
synthesis and dysfunctioning of mitochondria.
14.10.3 In Atopic Dermatitis (Eczema)
The GLA supplementation was first introduced to attenuate the signs and symptoms
of atopic dermatitis preceded by the oral dose of linoleic acid-rich oils (Sergeant
et al. 2016). Atopic dermatitis is a chronic inflammatory skin condition characterised
by red, itchy rashes normally on the cheeks, arms and legs. An estimated 10% of all
people worldwide are affected by atopic dermatitis at some point in their life
(National Eczema Association 2019). A growing literature has demonstrated the
beneficial effects of dietary GLA or GLA-rich oils on relieving the symptoms of
chronic dermatitis (Kawamura et al. 2011; Chung et al. 2002; Jung et al. 2014; Fujii
362
B. Tanwar et al.