spinach

Introduction
The use of herbal medicines continues to expand
rapidly across the world with many people now
resorting to these products for treatment of various
health challenges in different national healthcare
settings. Ease of availability, least side effects and
low cost of preparing herbal are the main key player
of all available therapies. Although usage of these
herbal medicines has increased, their quality, safety
and efficiency are serious concerns in industrialized
and developing countries thereupon traditional and
folklore medicines play an important role in health
services around the world (Ekor, 2013; Jadhav et al,
2015; Keshavarzi et al, 2013; Nikdehghan et al,
2013; Roughani and Miri, 2018).
Green leafy vegetables such as spinach are rich
sources of many nutrients and form a major category
of vegetable groups that have been designated as
‘nature anti-aging wonders’ and medicinal value
(Gupta and Prakash, 2009). Spinach is a valuable
crop for food and medicinal purposes with production
of over 26 million tons on about 921000 ha in the
world. About 25 million tons produced in Asia and
China with about 24 million tons was pioneer and
Iran was 6th in the 2016 on spinach production world
ranking by commodity about 117000 tons (FAO,
2018). Spinach-derived phytochemicals and
bioactives are able to scavenge reactive oxygen
species and prevent macromolecular oxidative
damage, modulate expression and activity of genes
involved in metabolism, proliferation, inflammation,
and antioxidant defence, and also curb food intake by
inducing secretion of satiety hormones (Roberts et al,
2016).
Botany and distribution
Spinach (Spinacia oleracea), belongs to
Chenopodiaceae family, is one of the most important
vegetables. It is a leafy cool-season vegetable with
global cultivation usually consumed after boiling
either fresh or frozen leaves or raw consumed in
salad (Alessa et al, 2017; Eriksen et al, 2016; Yoon et
al, 2017). It is native of Southwest Asia that thought
to have originated from Iran and has been grown in
China, since at least the 7th century and was used in
Europe, since at least the13th century (Cai et al, 2017;
Sabaghnia et al, 2016).
Spinach is an annual plant species and the closely
related species, S. tetranda, is considered to be its
ancestor, and other related species
comprise S. spinosa, S. inermis
and S. turkestanica. The classification of numerous
spinach cultivars is based on seed form (round or

prickly); leaf texture (smooth or crinkled); leaf
colour, shape and pose, and petiole length (AlKhayri, 2012). The edible leaves are arranged in a
rosette, from which a seed stalk emerges. The simple
leaves are somewhat triangular or ovate and may be
flat or puckered. The flowers are inconspicuous and
produce small dry fruits (Hassandokht, 2012). Sex of
spinach determined by the XY system. Male and
female floral organs differ morphologically, but
plants do not differ in the vegetative stage before
flowering (Fujita et al, 2017).
Breeding
The major aims of spinach breeding programs are to
develop varieties with traits including increased
disease resistance and abiotic stress tolerance such as
heat stress (Zhao et al, 2018), drought stress (Xu and
Leskovar, 2015), interactive salinity and water stress
(Ors and Suarez, 2017) and also improved yield and
quality such as decreased levels of nitrate and
oxalate, and increased levels of folate in spinach
leaves by different physiological and genetical
techniques (Hassandokht, 2012; Roughani et al,
2017).
Nutritional value
Spinach is a rich source of fiber, vitamins A, C, E, K,
B6, B2 and also magnesium, manganese, iron,
calcium, potassium, copper, phosphorous, zinc,
selenium, folate, betaine, folic acid, protein, niacin,
omega-3 fatty acids, carotenoids beta-carotene and
lutein, and bioflavonoid quercetin with many other
flavonoids. Spinach with poor source of fat is a
suitable food for obese and diabetic people. It is also
a good source of chlorophyll, which is known to aid
in digestion (Roughani et al, 2011; Gaikwad et al,
2010; Verma, 2018).
Medicinal uses
The leaves of spinach are traditionally used in
various folklore medicine as cooling, emollient,
wholesome, antipyretic, diuretic, maturant, laxative,
digestiblle, anthelmentic, urinary calculi,
inflammation of the lungs and the bowels, sore
throat, pain in joints, thirst, lumbago, cold and
sneezing, sore eye, ring worm scabies, leucoderma,
soalding urine, arrest vomiting, biliousness,
flatulence and febrile (Metha and Belemkar, 2014;
Verma, 2018).
Ameliorative effects of spinach seeds on carbon
tetrachloride induced hepatotoxicity. The in vitro and
in vivo hepatoprotective effects of spinach seeds were
examined and suggests that these seeds acts as

therapeutic agent in liver diseases. The seeds are
useful in fevers, leucorrhoea, urinary discharges,
lumbago, brain and heart diseases. Seeds are laxative
and cooling (Rao et al, 2015; Verma, 2018).
Pharmacological effects
Antidiabetic effects
The spinach antidiabetic activity may be due to the
presence of flavonoids such as kaempferol, qyricetin,
quercetin, apigenin and luteolin. It is reported that
flavanoids constitute the active biological principles
of most medicinal plants with hypoglycemic and
antidiabetic properties. The ethanolic and aqueous
extract of spinach leaves were orally tested at the
dose of 200 and 400 mg/kg for hypoglycaemic effect
in normal and alloxan-induced diabetic rats. In
addition, changes in body weight, serum cholesterol,
triglyceride assessed in the aqueous and ethanolic
extract treated diabetic rats, were compared with
diabetic control and normal animals histopathological
observations during 12 days treatment were else
evaluated. Spinach ethanolic and aqueous extract
produced a significant reduction in fasting blood
glucose levels in the normal alloxan-induced diabetic
rats. Also, significant differences were observed in
serum lipid profiles including cholesterol and
triglyceride and changes in body weight by both
ethanolic and aqueous treated diabetic animals.
Histopathological studies of the pancreas of these
animals showed comparable regeneration by extract
which were earlier necrosed by alloxan (Gomathi et
al, 2010; Nuutila et al, 2002). Chronic ulcer is still a
serious issue for diabetic patients. Diabetes is a
prevalent cause of ulcer regeneration delay and
disruption. Since spinach extract contains compounds
with anti‐oxidative and anti‐inflammatory effects,
this may be effective in accelerating the healing
process of ulcers, especially diabetic ulcers. In
macroscopic examination of the wounds of the
control group and spinach aqueous extract group
between 7 and 21 days compared with diabetic group,
significant changes were observed. On microscopic
examination, epithelial tissue formation, formation of
granulation tissue and new blood vessels in the
spinach aqueous extract group and non-diabetic
group compared to the diabetic group showed
significant improvements. Also, significant
differences in vascular endothelial growth factor
were observed between groups on days 3 and 7. The
spinach aqueous extract can be effective in
regenerating diabetic ulcers that improvement the
speed and structure of the ulcer (Rahati et al, 2015).
The protective potentials of the spinach leaf extract
(SLE) (50 mg/kg BW) studied against the systemic
LPS (5mg/kg BW) induced toxicity by evaluating
several toxicological parameters such as increased

oxidative burden in organs as depicted from
compromised antioxidant defense system (including
Glutathione system, MDA levels, Catalase activity),
cytokine levels and blood glucose levels. Glucose
levels were found to decrease significantly in LPS
treated animals as compared to control but SLE
normalise the level of glucose. The cytokines IL-1
and TNFα produced in liver regulate glucose
metabolism and may lead to hypoglycaemic effect in
response to LPS. Whereas, spinach co-administration
normalized the blood glucose level in LPS treated
animals as it regulates/inhibiting the expression of
these pro-inflammatory cytokines i.e., IL-1β and
TNF-α. The nutritional value and in vitro antioxidant
as well as antidiabetic potential of spinach were
determined. The methanolic extract of spinach was
prepared using Soxhlet extraction technique which
was subjected for physicochemical, nutritional value
determination along with the OH-scavenging, 2,2-
diphenyl-1-picrylhydrazyl and α-amylase inhibition
activity. The results demonstrated the good
nutritional values such as total crude fiber, proteins,
oils and fats, carbohydrate, and vitamins A and C.
Moreover, methanolic extract of spinach showed the
antioxidant activity and antidiabetic effect with an
inhibitory concentration of 3.03 µg/ml, 6.03 µg/ml
and 3.046 µg/ml for OH-scavenging, 2,2-diphenyl-1-
picrylhydrazyl inhibition and α-amylase inhibition,
respectively (Kapoor et al, 2017; Sah et al, 2017).
Antioxidant activity
Rao et al (2015) compared the effect of drying in
fresh and dried leaves with reference to the phytoconstituents. There was no change in the
phytochemical constituents present in fresh and dried
leaves of spinach. The anti-inflammatory, laxative
and antioxidant property may be due to the presence
of glycosides such as coumarins, anthroquinones,
steroids and flavonoids, respectively. Loss of water
content on drying has no effect on the extractive
values of leaves and phyto-constituents. So the dried
leaves can be used for its medicinal values and can be
stored till its use. The antioxidant properties and
stability of spinach polyphenols evaluated by Sun et
al (2018) via two common methods including 1,1-
diphenyl-2-picrylhydrazyl radical scavenging activity
and ferric reducing antioxidant power. Results
demonstrated that spinach polyphenol had a certain
antioxidant activity, and its antioxidant ability
increased with the increase of sample concentration.
External factors, such as pH value, temperature, light
and preservative, have different effects on their
antioxidant stability.