Nutrients, herbals and dietary supplements are major components of nutraceuticals which are instrumental in maintaining health, act against various disease conditions and thus promote the quality of life. Diabetes mellitus is one of them. Management of diabetes with nutraceuticals-based approach includes intake of functional foods and herbal supplements. Nutraceuticals are food supplements and have nutritional value and exhibit significant clinical & pharmacological activity. The potency of herbal drugs is significant & they have negligible side effects than the synthetic antidiabetic drugs.
Diabetes mellitus is a group of diseases characterized by high levels of glucose in the blood resulting from defects in insulin production (insulin deficiency), insulin action (insulin resistance), or both. Consistently high levels of glucose in the bloodstream damage the nerves and blood vessels, and can lead to heart disease, stroke, high blood pressure, blindness, kidney disease, amputations, and dental disease. According to IDF Diabetes Atlas 2017, Some 425 million people worldwide, or 8.8% of adults 20-79 years, are estimated to have diabetes. About 79% live in low and middle-income countries. The number of people with diabetes increases to 451 million if the age is expanded to 18-99 years. If these trends continue, by 2045, 693 million people 18-99 years, or 629 million of people 20-79 years, will have diabetes.
Several medicinal plants are used as hypoglycaemic in the Indian system of medicines, including Ayurveda. Nutraceuticals denote foods having medicinal effect on the health of human beings. Nutraceuticals have the capability to control diabetes.
Nutraceuticals are non-specific biological therapies used to promote wellness, prevent malignant processes and control symptoms. These can be grouped into the following three broad categories .
1. Substances with established nutritional functions, such as vitamins, minerals, amino acids and fatty acids - Nutrients
2. Herbs or botanical products as concentrates and extracts - Herbals
3. Reagents derived from other sources (e.g. pyruvate, chondroitin sulphate, steroid hormone precursors) serving specific functions, such as sports nutrition, weight-loss supplements and meal replacements-Dietary supplements.
Acacia arabica (Babhul): It is of Mimosaceae family and found all over India mainly in the wild habitat. It acts through release of insulin from pancreatic beta cells, which accounts for the hypoglycaemic activity . Powdered seeds of Acacia arabica when administered orally (2,3 and 4g/kg body weight) to normal rabbits induced hypoglycaemic effect by initiating release of insulin from pancreatic beta cells .
Aegle marmelos (Holy Fruit Tree): It is of Rutaceae family and found in the plains and sub mountain regions of India. The proposed mechanism of action is that it increases utilization of glucose; either by direct stimulation of glucose uptake or via the mediation of enhanced insulin secretion . Antihyperglycemic activity of the leaves in glucose induced hyperglycaemic rat at an oral dose equivalent to 250mg/kg .
Allium cepa (Onion): It is of Liliaceae family and cultivated
as an annual all over the country. It lowers blood glucose level
and has potent antioxidant activity, which may account for the
hypoglycaemic potential . Hypoglycaemic activity of the onion
is attributed to the allyl propyldisulphide and allicin
Allium sativum (Garlic): It is of Liliaceae family. It Has strong
antioxidant activity and rapid reactivity with thiol containing
proteins responsible for the hypoglycaemic. property . Allicin,
has been shown to have significant hypoglycaemic activity.
Ethanol, petroleum ether and ethyl acetate extract in alloxanized
rabbits at a dose of 0.25mg/kg, orally shows antihyperglycemic
activity 79.3g of bulb is enough for control of diabetes.
Aloe Vera (Aloe): Aloe Vera maintains glucose homeostasis
by controlling the carbohydrate metabolizing enzymes 
and stimulates insulin release from pancreatic beta cells .
Hypoglycaemic activity of the plant (200 and 300 mg/kg p.o.)
has been done on normal fasted rats, oral glucose-loaded rats
and streptozotocin-induced diabetic rats . Aloe Vera showed
antihyperglycemic activity when one tablespoonful aloe juice
was given orally in the morning and at bedtime to diabetic
patients for 42 days. Leaf pulp juice of 10–20 ml is used to
Azadirachta indica (Neem): It is of Meliaceae family. It
inhibits action of epinephrine on glucose metabolism, resulting
in increased utilization of peripheral glucose . Hydro alcoholic
plant extract in normal rats and in glucose fed and streptozotocin
induced diabetic rats’ shows hypoglycemic activity [10,11]. Leaf
juice of 10-20ml is used to control diabetes.
Caesalpinia bonducella (Fever Nut): It is of Caesalpiniaceae
family. It increases the release of insulin from pancreatic
cells. Aqueous and 50% ethanolic seed extracts in normal
and streptozotocin-diabetic rats’ shows hypoglycemic and
antihyperglycemic activities . 1-3g of Seed kernel powder is
used to control diabetes.
Coccinia indica (Kundru): It is of Cucurbitaceae family. It
suppresses glucose synthesis, through depression of the key
gluconeogenic enzymes glucose-6-phosphatase and fructose-1,
6-bisphosphatase and enhances glucose oxidation by shunt
pathway through activation of its principal enzyme glucose-6-
phosphate dehydrogenase . Dried extract (500mg/kg p.o.,
for 6 weeks) in 30 diabetic patients give antihyperglycemic
activity . 3-6g powder of Whole plant and 5-10ml juice is
used to treat diabetes.
Eugenia jambolana (Jamun): It is of Myrtaceae family. The
activity may be mediated through an insulin release mechanism
 or due to alteration in hepatic and skeletal muscle glycogen
content and hepatic glucokinase, hexokinase, glucose-6-
phosphate and phosphofructokinase levels in diabetic mice
. In India decoction of kernels of Eugenia jambolana is used
as household remedy for diabetes. Aqueous, alcoholic extracts
and lyophilized powder (200mg/kg per day) of the plant in
hyperglycaemic animals shows hypoglycaemic effect . It also
shows blood glucose lowering activity of aqueous seed extract
(2.5 and 5.0g/kg body weight p.o. for 6 weeks) along with an
increase in total haemoglobin and antioxidant activity in diabetic
Gymnema sylvestre (Gurmar): This Indian plant has
traditionally been used to treat diabetes—and is helpful for both
Type I and Type II diabetics. it increases secretion of insulin, it
promotes regeneration of islet cells, it increases utilization of
glucose and it is shown to increase the activities of enzymes
responsible for utilization of glucose by insulin-dependent
pathways, an increase in phosphorylase activity, decrease in
gluconeogenic enzymes and sorbitol dehydrogenase and it also
causes inhibition of glucose absorption from intestine [18,19].
In liquid form (extract), 25 to 75ml per week is recommended.
Best results of this medicine will come after 6 to 12 months of
continuous use .
Linum usitatissimum (Flax Seeds): Flax seeds are the
dried ripe seeds of family Linaneae. Flax seeds contain antioxidants
and have high dietary fibre that can help diabetics by
inhibit lipid peroxidation and scavenging of hydroxy radicals.
Dietary fibres of flaxseeds contain about 6% mucilage which has
nutritional value. Secoisolariciresinol diglycoside (SDG), a plant
lignan found in flaxseed, has been found to possess antioxidant
Momordica charantia (Bitter Gourd): It is of Cucurbitaceae
family, cultivated all over India for its fruits. It may act by
increasing hepatic glycogen . The fruits and seeds yielded a
polypeptide, p-insulin, which was considered like bovine insulin
. Vicine is the hypoglycaemic constituent in the seed. There
is blood glucose level reducing activity of fruit powder in fasted
alloxan-induced diabetic rats after a treatment for 15 days .
Ocimum sanctum (Tulsi): It is of Labiatae family, the
aqueous extract of leaves of Ocimum sanctum showed the
significant reduction in blood sugar level in both normal and
alloxan induced diabetic rats. It may act by cortisol inhibiting
potency . Leaf powder, given along with food for 1 month,
in normal and diabetic rats reduces fasting blood glucose level
. 50-10ml plant infusion is used as dosage of tulsi.
Pterocarpus marsupium (Vijaysar): It is of Papilionaceae
family; found throughout the tropical zones of India in the
hilly regions. Different parts of the plant like bark, latex, etc.
were investigated and reported to have hypoglycaemic activity
[26,27]. Various active components like epicatechin, marsupsin,
pterosupin and pterostilbene, isolated from the bark and
heartwood of the plant, were also found to possess blood sugar
lowering activity1 . Stem bark -32-50g for decoction is used
to control diabetes.
Trigonella foenum-graecum (Fenugreek): It is of
Papilionaceae family, widely cultivated in many parts of India. It
increased glucose-induced insulin release through a direct effect on the isolated islets of Langerhans. Various extracts of different
parts of this plant; fibres, proteins and saponins isolated from
the seeds were investigated and found to possess significant
hypoglycaemic activity . Trigonella seeds and the major
alkaloid component, Trigonelline, exerted a mild hypoglycaemic
effect.3-5g of seed powder is used to treat diabetes .
Tinospora cordifolia (Guduchi): It is of Menispermaceae
family, found in tropical India and the Andamans. Various
extracts of the leaves of this plant were investigated for their
blood sugar lowering activity in normal and alloxanized rabbits
in graded doses and the findings have proved that the plant has
potent hypoglycaemic activity .
Nutraceuticals are food supplements and have nutritional
value. All the nutrients discussed in this review have exhibited
significant clinical & pharmacological activity. There is
increasing demand by patients for use of the natural products
with antidiabetic activity. A well-balanced vegetarian diet
chosen to form a variety of foods when complemented with
other healthy lifestyle practices would significantly decrease
the risk for diabetes mellitus. The efficacy of hypoglycaemic
herbs is achieved by increasing insulin secretion, enhancing
glucose uptake by adipose and muscle tissues, inhibiting glucose
absorption from intestine and inhibiting glucose production
from hepatocytes. A place for nutraceuticals in clinical practice
is emerging, but important pharmaceutical and clinical issues
need to be addressed by further research.