INTRODUCTION:

Ayurvedic medicines mainly based on plants enjoy a respective position today, especially in the developing countries, where modern health services are limited. Safe effective and inexpensive indigenous remedies are gaining popularity among the people of both urban and rural areas especially in India and China. Information from ethnic groups or indigenous traditional medicines has played vital role in the discovery of novel products from plants as chemotherapeutic agents. Herbal medicines have been main source of primary healthcare in all over the world. From ancient times, plants have been catering as rich source of effective and safe medicines. About 80 % of world populations are still dependent on traditional medicines. Herbal medicines are finished, labeled medicinal products that contain as active ingredients, aerial or underground part of plants or other plant materials, or combination thereof, whether in the crude state or as plant preparations. Medicines containing plant materials combined with chemically defined active substances, including chemically defined isolated constituents of plants are not considered to be herbal medicines.¹

Herbal medicines continue to be a major market in US pharmaceuticals and constitute a multi-billion dollar business. Approximately 1500 botanicals are sold as dietary supplements; formulations are not subject to Food and Drug Administration (FDA) clinical toxicity testing to assure their safety and efficacy. The Indian herbal drug market size is about $1 billion and the export of plant based crude drug is around $100 million. The current market potential of herbal medicine is estimated about $ 80-250 billion in Europe and USA.

The current market size of the herbs and natural health products in China is about USD 650 million, of which imported herbal medicines account for USD 15 million. In response to the expected improvement in modern herbal medicine and reflective of their growing demand for natural medicines, 73 % of the respondents to a consumer survey indicated they would depend more on herbal medicine in the future. Imports of herbs into Hong Kong in 2003 amounted to USD 166.4 million, a 6.8 % decrease over the 2002’s imports. This reflects less imports of licorice roots of USD 0.2 (−23.8 %) and ginseng root of USD 123.2 (−8.8 %). ²

The aim of the present review is to understand the knowledge of plants used for Ayurvedic preparations in relation to their use as therapeutic agents, pharmacological properties, medicinal plants being imported; medicinal plant parts being exported, endangered medicinal plants and availability of medicinal plants in different bio-geographical zones of India. The authors have tried to put all these classes of plants at a common platform so that the data and information of this review could be utilized in drawing strategies for use of medicinal plants in a way that can be extended for future scientific investigation in different aspects. The Ayurvedic concept appeared and developed between 2500 and 500 BC in India. The literal meaning of Ayurveda is “science of life,” because ancient Indian system of health care focused views of man and his illness. It is pointed out that the positive health means metabolically well-balanced human beings. The practice of Ayurveda therapeutics consisted of 8 sections divided into 180 chapters and listed 314 plants, which are used as medicines in India³.

Diabetes, is a group of metabolic diseases in which there are high blood sugar levels over a prolonged period.Symptoms of high blood sugar include frequent urination, increased thirst, and increased hunger. If left untreated, diabetes can cause many complications. Acute complications include diabetic ketoacidosis and nonketotic hyperosmolar coma. Serious longterm complications include cardiovascular disease, stroke, chronic kidney failure, foot ulcers, and damage to the eyes.

Diabetes is due to either the pancreas not producing enough insulin or the cells of the body not responding properly to the insulin produced. There are three main types of diabetes mellitus. ⁴

Type 1 DM results from the pancreas' failure to produce enough insulin. This form was previously referred to as "insulindependent diabetes mellitus" (IDDM) or "juvenile diabetes".

The cause is unknown.

Type 2 DM begins with insulin resistance, a condition in which cells fail to respond to insulin properly.As the disease progresses a lack of insulin may also develop.[6] This form was previously referred to as "non insulin dependent diabetes mellitus" (NIDDM) or "adult onset diabetes".

The primary cause is excessive body weight and not enough exercise.Gestational diabetes, is the third main form and occurs when pregnant women without a previous history of diabetes develop a high blood sugar level. Prevention and treatment involve a healthy diet, physical exercise, not using tobacco and being a normal body weight. Blood pressure control and proper foot care are also important for people with the disease⁵.

Type1 diabetes must be managed with insulin injections.

Type 2 diabetes may be treated with medications with or without insulin.

Insulin and some oral medications can cause low blood sugar. Weight loss surgery in those with obesity is sometimes an effective measure in those with type 2 DM. Gestational diabetes usually resolves after the birth of the baby. ⁶

Antidiabetic Drugs^{7, 8, 9}

Drugs used in diabetes treat diabetes mellitus by lowering glucose levels in the blood. With the exceptions of insulin, exenatide, liraglutide and pramlintide, all are administered orally and are thus also called oral hypoglycemic agents or oral antihyperglycemic agents. There are different classes of antidiabetic drugs, and their selection depends on the nature of the diabetes, age and situation of the person, as well as other factors.

Insulin:

Insulin is usually given subcutaneously, either by injections or by an insulin pump. Research of other routes of administration is underway. In acutecare settings, insulin may also be given intravenously. In general, there are three types of insulin, characterized by the rate which they are metabolized by the body. They are rapid acting insulins, intermediate acting insulins and long acting insulins.

Examples of rapid acting insulins include

· Regular insulin (Humulin R, Novolin R)

· Insulin lispro (Humalog)

· Insulin aspart (Novolog)

· Insulin glulisine (Apidra)

· Prompt insulin zinc (Semilente, Slightly slower acting)

Examples of intermediate acting insulins include

· Isophane insulin, neutral protamine Hagedorn (NPH) (Humulin N, Novolin N)

· Insulin zinc (Lente)

Examples of long acting insulins include

· Extended insulin zinc insulin (Ultralente)

· Insulin glargine (Lantus)

· Insulin detemir (Levemir)

List of some antidiabetic plants ^{13, 14, 15}

Botanical name and local name	Reported Action	Chemical constituents identified as antidiabetic	Mechanism of action
Acacia arabica Babul	Anti-diabetic action	-	Insulin release
Aegle marmelose Bael	Controlled the blood glucose, urea, body weight, liver glycogen, serum cholesterol	Alkaloids	Insulin release, decreased malate dehydrogenase
Allium cepa Pyaj	Hypoglycemic action (ethyl acetate fraction) Antihyperglycemic action (petroleum ether)	S-methyl cysteine	Normalized the activities of liver hexokinase, glucose 6-phosphatase.
Allium sativum Garlic	Hypoglycemic action , hepatic glycogen action, fasting blood glucose decreases, triglycerides decreases	S containing amino acid	Stimulates the synthesis or release of insulin
Andrographis paniculata Nees	-	Andrographolide	-
Artemisia pallens Davana	Antihyperglycemic action	-	Increased glucose utilization or inhibited glucose reabsorption
Areca catechu Supari	Hypoglycemic effect	Nitrosamines Alkaloid	-
Azadirachta indica Neem	Hypoglycemic action and antihyperglycemic action	-	Plant blocks the action of epinephrine on glucose metabolism
Beta vulgaris Chukkander	Inhibition of non-enzymatic glycosylation of skin proteins	Beta vulgarosides II, III and IV	Increases the glucose tolerance.inn OGTT.
Brassica juncea Seeds	Hypoglycemic action	-	-
Caesalpinia bonducella Kantkarej	Hypoglycemic action and antihyperglycemic action	-	-
Carica papaya Linn. Papaya	Hypoglycemic action	Glycosides, papain mineral salts and polysaccharides	-
Citrullus colocynthis Badi indrayan	Hypoglycemic	Glycosides, alkaloids and sapaonins	Significant Insulin release
Eucalyptus globules Safeda	No hypoglycemia Decreased polydepsia Prevented body loss	-	Increased peripheral glucose utilization. ↑ insulin secretion
Ficus bengalenesis Banyan tree	Hypoglycemic action	Glucoside, pelaronidine and leucopelarogonodone	Increases the insulin level and decreasing the insulinase activity
Gymnema sylvestre Gudmar	Antihperglycemic action Normalized blood glucose Decreased HbA1_c, ↓ lipid	Gymnemosides, Gymnemic acid	Decrease in gluconeogenic enzymes Β-cell regeneration,
Hibiscus rosa Gudhal	Hypoglycemic action	-	Increases the insulin release by stimulation of pancreatic beta cells or an increase of the glycogen deposition in liver.
Ipomeo batatas Sakkargand	Reduces hyperinsulinemia in Zucker fatty rats	-	Reduction in insulin resistance
Lantana camara Caturang	Hypoglycemic action But hepatotoxic in nature	-	-
Mangifera indica Aam or Amb	Antidiabetic action if given concurrently with glucose	-	Reduction in intestinal absorption of glucose
Memecylon umbellatum Anjani	Significant reduction in the serum glucose levels	-	-
Momordica charantia Karela	Hypoglycemic action Antihyperglycemic action Anticataract	Polypeptide, oleanolic acid, 3-O-glucoronide Momordin I_c	Inhibited the glucose-6-phosphatase and fructose-1,6-bi phosphate
Morus alba Shetut	Hypoglycemic action	Alkaloids	Glycosidase inhibitory activity.↑glucose uptake.
Murray loeingii Kurry patta	Hypoglycemic action	-	Insulin like action
Occimum sanctum ;Tulsi	Significant reduction	-	-
Phyllanthus niruri Jangli amla	Hypoglycemic and antidiabetic activity	Bioflavanoids, Vitamin C, emblicanin A, B	-
Punica grantum Anar	Antidiabetic	-	-
Swertia chiraytia Chirata	Hypoglycemic action Antihyperglycemic action	Swerchirin	Stimulated the insulin release
Syzigium cumini Jamun	Hypoglycemic action Reduced the glycosuria Restored the hepatic glycogen, hepatic glucokinase, hexokinase	-	Increases the activity of cathepsin B Inhibited the isulinase activity
Trigonella foenum graecum Methi	Hypoglycemic action Antihyperglycemic action Antiglycosoric effect Normaised the altered creatinine kinase.	Fibres, saponins, poteins 4-hydroxyisoleucine	Stimulated the insulin secretion in absence of pancreatic, α pancreatic δ-pancreatic cells
Tinospora cordifolia Guduci	Hypoglycemic action Decresed the brain lipid level, alkaline and lactate dehydrogenase	-	-
Vinca rosea Sadabahar	Antihyperglycemic	-	-

PLANT PROFILE^{16, 17, 18}

Acacia nilotica Leaf:

Vernacular Names:

Hindi : Karuvela maram

Chinese : Acabin nilotica

Classfication:

Kingdom : Plantae

(unranked) : Angiosperms

(unranked) : Eudicots

(unranked) : Rosids

Order : Fabales

Family : Fabaceae

Genus : Vachellia

Species : V. nilotica

Fig. 1 Acacia nilotica Leaf

Origin and distribution:

The species is widespread in Africa and Asia, and occurs in Australia and Kenya. Indian gum Arabic tree is found in well watered Sahelian and Sudanian savannas to the southern Arabian Peninsula, East Africa and in the Gambia, the Sudan, Togo, Ghana, and Nigeria. It is widely cultivated in the Indian subcontinent, and also found on lateritic soil in the Himalayan foothills in India.

Plant description:

Acacia nilotica is a single stemmed plant, grows to 15-18 m in height and 2-3 m in diameter.

Pods and Seeds:

Pods are 7-15 cm long, green and tomentose (when immature) or greenish black (when mature), indehiscent, deeply constricted between the seed giving a necklace appearance. Seeds are 8-12 per pod, compressed, ovoid, dark brown shining with hard testa.

Leaves:

The leaves are bipinnate, pinnate 3-10 pairs, 1.3-3.8 cm long, leaflets 10-20 pairs, and 2-5mm long. Flowers: Flowers are globular heads, 1.2-1.5 cm in diameter of a bright golden yellow colour, develop either in axillary or whorly pattern on peduncles 2-3 cm long located at the end of branches.

Flowers:

Flowers are globular heads, 1.2-1.5 cm in diameter of a bright golden yellow colour, develop either in axillary or whorly pattern on peduncles 2-3 cm long located at the end of branches.

Stem:

Stems are usually dark to black coloured, deep longitudinal fissured, grey-pinkish slash, exuding a reddish low quality gum.

Bark:

The bark a tinge of orange and/or green (young tree), but older trees have dark, rough bark and tend to lose their thorns. Thorns: Thorns are thin, straight, light grey exist in axillary pairs (usually 3-12), 5-7.5 cm long in young trees. Root: Root is generally of brown colour in older and whitish in younger regions.

Gum:

The gum varies in colour from very pale yellowish brown to dark reddish brown depending on the quantity of tannins in the sample. The lighter, more highly valued gums are soluble in water and very viscous; the tannins in the darker gum reduce the solubility. The gum has a moisture content of about 13% and is slightly dextrorotary.

Chemical constituents:

It contains a high percentage of phenolic constituents consisting of m-digallic acid, gallic acid, its methyl and ethyl esters, protocatechuic and ellagic acids, leucocyanidin, m-digallic dimer 3,4,5,7-tetrahydroxy flavan-3-ol, oligomer 3,4,7- trihydroxy flavan 3,4-diol and 3,4,5,7-tetrahydroxy flavan-3-ol and (-) epicatechol. Fruit also contains mucilage and saponins. Also is rich in phenolics consisting of condensed tannins and phlobetannin, gallic acid, protocatechuic acid pyrocatechol, (+)–catechin, (-) epigallocatechin-5, 7-digallate, apigenin, 6-8-bis-D-glucoside, and rutin.

Uses:

Leaves used for feeding sheep and goats in the Hissar district in India. In Kenya, the fleshy pods are readily eaten by goats, sheep and cattle, but some tribes believe they cause bloat. They are occasionally browsed by goats. The wood is hard and heavy, difficult to work as it blunts tools for its high content in silica ; it is regarded, however, as excellent quality timber and service wood, poles, carpentry, boat and house construction, it is also considered a very good fire-wood and produces an excellent charcoal. Bark and pods are used in the tanning industry, leaves are readily browsed by stock, and they have an average 12 % crude protein content. Young pods and seeds are eaten roasted by humans. Subsp. indica is regarded as an excellent forage tree producing large amounts of nutritious pods with little tannin. Bark and leaves are used to treat haemorrhage, colds, diarrhoea, scurvy, dysentry and ophtalmia etc.

Photograph 2: Photograph of various parts of A. nilotica:

Seed part

Leaves part

Bark part

Root part

METHODOLOGY:

Extraction:

The correctly identified leaves of Acacia nilotica are dried and coarsely powdered. They should be extracted with methanol solvent in order to their increasing polarity to get correct and dependable retention factor to get significant results.

Preparation of extract:

Hydroalcoholic extraction:

Plant material was subjected to hot continuous extraction with Hydroalcoholic (80:20% v/v) (40-45^oC) in a Soxhlet apparatus for 24 hours.

The extraction procedure was ensured by pouring a few drops of extract from thimble left no residue on evaporation. After complete extraction the solvent was evaporated and concentrated to dry residue. % yield was calculated for extract after drying under vacuum.^{19, 20}

Fig. No. 3 Hydroalcoholic extract of Acacia nilotica

Determination of percentage yield:

The percentage yield of each extract was calculated by using following formula:

Weight of Extract

Percentage yield=---------------------------------- x 100

Weight of powder drug Taken

Phytochemical Screening:

The chemical tests were performed for testing different chemical groups present in extracts. ^{21, 22, 23, 24}

A. Alkaloids:

To the extract dilute hydrochloric acid was added. Then it was boiled and filtered.

i. Mayer’s test:

To 2-3 ml of filtrate, few drops of the Mayer’s reagent were added. Formation of cream precipitate indicated the presence of alkaloids.

ii. Dragendorff’s test:

To 2-3 ml of filtrate, few drops of the Dragendorff’s reagent were added. Formation of orange brown precipitate indicated the presence of alkaloids.

iii. Hager’s test:

To 2-3 ml of filtrate, few drops of Hager’s reagent were added. Formation of yellow precipitate indicated the presence of alkaloids.

iv. Wagner’s test:

To 2-3 ml of filtrate, few drops of Wagner’s reagent were added. Formation of reddish brown precipitate indicated the presence of alkaloids.

B. Carbohydrates:

i. Molisch’s test (General test):

In a test tube containing 2 ml of extract, 2 drops of freshly prepared 10 per cent alcoholic solution of α- naphthol was added. Then it was shaken and 2 ml of Conc. sulphuric acid was added from sides of the test tube. So the violet ring was formed at the junction of two liquids, indicated the presence of carbohydrates.

ii. Fehling’s test (Reducing sugars):

To 2 ml of extract, equal volume of mixture of equal parts of Fehling’s solution A and B were added and boiled for few minutes in boiling water bath. Formation of red or brick red coloured precipitate indicated the presence of reducing sugars.

iii. Benedict’s test (Reducing sugars):

Equal volume of Benedict’s reagent and test solution were added in a test tube and boiled for 5 min in a water bath. Formation of green, yellow or red coloured precipitate depending on amount of reducing sugar present in test solution indicated the presence of reducing sugar.

C. Flavonoids:

i. Ferric-chloride test:

Test solution with few drops of ferric chloride solution shows intense green colour.

ii. Alkaline reagent test:

To 2 ml of test solution add 2 ml alkali, gives yellow color, which disappears on addition of dil. HCl it disappears, which indicates presence of flavonoids.

iii. Shinoda’s test:

In a test tube containing 0.5 ml of the extract, a small piece of magnesium was added. Then few drops of conc. hydrochloric acid was added. Formation of pink colour indicated the presence of flavonoids.

D. Proteins:

i. Biuret’s test (General test)

To 1 ml of test extract, 4% of sodium hydroxide solution and few drops of 1% copper sulphate solution were added. Formation of a violet red colour indicated the presence of proteins.

E. Saponins:

i. Foam test:

The extract was shaken vigorously with water in a test tube. Formation of persistent foam indicated the presence of saponins.

ii. Haemolytic test:

Few drop of extract solution was mixed with Blood, which indicates haemolysis, shows presence of saponin.

iii. Salkowaski test:

Concentrated sulphuric acid (2 ml) was added to 2 ml of test solution. The solution was shaken and allowed to stand. The colour of lower layer changed to yellow indicating presence of triterpenoids.

F. Steroids:

i. Salkowski test:

To 2 ml of extract, 2 ml of chloroform and 2 ml of concentrated sulphuric acid were added and shaken, red color at lower layer indicated the presence of steroids.

ii. Liebermann-burchard reaction:

T.S 2 ml was mixed with chloroform (2 ml). To the solution, 2 ml of acetic anhydride and 2 drops of conc. Sulphuric acid from the side of test tube were added. Change in colour first red, then blue and finally green indicated presence of steroids

G. Amino acid:

i. Ninhydrin test (General test):

3 ml of test solution and 3 drops of 5% ninhydrin solution in a test tube were heated in boiling water bath for 10 minutes. Formation of Purple or bluish colour indicated the presence of amino acid.

ii. Millons test:

T.S (3 ml) and Million’s reagent (5 ml) were mixed in a test tube. The appearance of white precipitate changing to brick red or dissolved and gave red color to solution on heating indicated presence of proteins.

iii. Xanthoprotic test:

To the test tube containing T.S (3 ml), 1 ml of conc. Sulphuric acidwas added. Appearance of white precipitate which turns yellow on boiling and orange on addition of NH₄OH indicated presence of tyrosin and/or tryptophan containing proteins.

H. Glycosides:

General test

Test A: 200 mg of extract were diluted with 5 ml of dilute sulphuric acid by warming on a water bath and filtered it. Then the acid extract was neutralized with 5% solution of sodium hydroxide. Then 0.1 ml of Fehling’s solution A and B were added until it became alkaline (test with pH paper) and heated on a water bath for 2 minutes. Noted the quantity of red precipitate formed and compared with that of formed in test B.

Test B:

200 mg of extract was diluted with 5 ml of water instead of sulphuric acid. Then equal amount of water (as used for sodium hydroxide in the above test) after boiling was added. Then 0.1 ml of Fehling’s solution A and B were added until it became alkaline (test with pH paper) and heated on a water bath for 2 minutes. Noted the quantity of red precipitate formed. The quantity of precipitate formed in test B was compared with that formed in test A. If the precipitate in test A was greater than in test B then glycoside may be present. Since test B represents the amount of free reducing sugar already present in the crude drug, whereas test A represents free reducing sugar plus those related on acid hydrolysis of any glycoside in the crude drug.

i. Baljet test:

2 ml of the test solution was treated with 2 ml of sodium picrate solution. The development of yellow to orange colour indicated presence of cardiac glycosides

ii. Legals test:

To 2 ml of test solution, 1 ml of pyridine and 1 ml of sodium nitroprusside was added. Change in color to pink or red indicated presence of cardiac glycosides.

iii. Killer Killiani test:

Glacial acetic acid (3-5 drops), one drop of 5% FeCl₃ and conc. Sulphuric acid were added to the test tube containing 2 ml of T.S. Appearance of reddish-brown color at the junction of two layers and bluish green in the upper layer indicated presence of glycosides.

I. Tannins:

i. Ferric chloride test:

Extract solutions were treated with 5% ferric chloride solution. Formation of blue colours indicated the presence of hydrolysable tannins and formation of green colour indicated the presence of condensed tannins

ii. Lead acetate test:

Extract solutions were treated with 5% lead acetate solution. Formation of white precipitate indicated the presence of hydrolysable tannins.

iii. Gelatin test:

3 ml of test solution when treated with gelatin solution (3ml) gave white precipitate.

Total Phenolic content estimation:

Principal:

The total phenolic content of the extract was determined by the modified Folin-Ciocalteu method.

Preparation of Standard:

50 mg Gallic acid was dissolved in 50 ml methanol, various aliquots of 25- 400g/ml was prepared in methanol

Preparation of Extract:

1gm of dried powder of drug was extracted with 100 ml methanol, filter, and make up the volume up to 100 ml. One ml (1mg/ml) of this extract was for the estimation of flavonoids.

Procedure:

1 ml of extract or standard was mixed with 5 ml of Folin-Ciocalteu reagent (previously diluted with distilled water 1:10 v/v) and 4 ml (75g/l) of sodium carbonate. The mixture was vortexed for 15s and allowed to stand for 30min at 40°C for colour development. The absorbance was measured at 765 nm using a spectrophotometer.

Total flavonoids content estimation:

Principal:

Determination of total flavonoids content was based on aluminium chloride method

Preparation of standard:

50 mg quercetin was dissolved in 50 ml methanol, and various aliquots of 25-200g/ml were prepared in methanol.

Preparation of extract:

1gm of dried powder of drug was extracted with 100 ml methanol, filter, and make up the volume up to 100 ml. One ml (1mg/ml) of this extract was for the estimation of flavonoid.

Procedure:

1 ml of 2% AlCl₃ methanolic solution was added to 1 ml of extract or standard and allowed to stand for 60 min at room temperature; absorbance was measured at 420 nm.

In vivo Anti diabetic activity^{25, 26, 27}

Materials and methods:

Animals:

Wistar rats (150–200 g) were group housed (n=6) under a standard 12 h light/dark cycle and controlled conditions of temperature and humidity (25±2 °C). Rats received standard rodent chow and water ad libitum. Rats were acclimatized to laboratory conditions for 7 days before carrying out the experiments. All the experiments were carried in a noise-free room between 08.00 to 15.00 h. Separate group (n=6) of rats was used for each set of experiments. The animal studies were approved by the Institutional Animal Ethics Committee (IAEC), constituted for the purpose of control and supervision of experimental animals by Ministry of Environment and Forests, Government of India, New Delhi, India.

Chemicals:

Streptozotocin (Central Drug House Pvt.Ltd, India), Glibenclamide tablets (Daonil; Aventis Pharma. Ltd., India) were procured from the authorized distributor of the company. All other chemicals were used in present study.

Acute toxicity:

Toxicity studies were carried out in accordance with OECD guidelines, acute oral toxicity study of leaves hydroalcoholic extract of Acacia Nilotica. The Acacia Nilotica (50, 100, 150, 200, 300 mg/kg/day) was administered orally for 4 days of six groups of rats (n=6) and the animals were kept under examination for mortality as well as any behavioral changes.

Induction of Experimental Diabetes in Rats:

After fasting, diabetes was induced by a single intraperitoneal injection of 120 mg/kg body weight of 'Streptozotocin monohydrate' in distilled water. The animals were allowed to drink 5% glucose solution overnight to overcome the drug-induced hypoglycemia. These animals were tested for diabetes after 15 days and animals with blood glucose (fasting) were selected for experimentation.

Experimental Protocol:

Animals were divided into five groups of 6 rats each

Group I:

Rats served as normal-control and received the vehicle (0.5 ml distilled water/day/rat)

Group II:

Rats served as diabetic-control and received the vehicle (0.5 ml distilled water/day/rat)

Group III:

Rats (diabetic) were administered Acacia Nilotica (100 mg/kg p.o.) for 15 days.

Group IV:

Rats (diabetic) were administered Acacia Nilotica (200 mg/kg p.o.) for 15 days.

Group V:

Rats (diabetic) were administered Glibenclamide (600µg/kg p.o.) for 15 days.

Statistical Analysis:

The data were expressed as mean ± SEM. The data of hypoglycemic activity, oral glucose tolerance test and antidiabetic activity were analyzed by one way analysis of variance (ANOVA) followed by “Dunnett’s test.” p value less than 0.05 was considered as statistically significant.

RESULT AND DISCUSSION:

Table no: 1 Extraction of plant material % yield value of plant Hydro-alcoholic extraction

S. No.	Solvent	% Yield (W/W)
1.	Hydro alcoholic (50%)	12.25%

Table no: 2 Phytochemical screening of extracts

Chemical Tests	Results
Alkaloids
Mayer’s reagent	+ ve
Hager’s reagent	+ ve
Wagner’s reagent	+ ve
Dragendorff’s reagent	+ ve
Glycosides (+Ve)
Baljet test	- ve
Legal’s test	- ve
Keller-Kiliani	- ve
Phenols/Tannins
Ferric chloride	+ ve
Gelatin Solution	+ ve
Lead acetate test	+ ve
Flavonoids
FeCl3 test	+ ve
Alkaline reagent test	+ ve
Shinoda test	+ ve
Saponins
Foam test	- ve
Hemolytic test	- ve
Lead acetate	- ve
Fixed oil/Fats
Spot	+ ve
Saponification	+ ve
Gums & Mucilage
Water	- ve
Carbohydrates
Molish test	+ ve
Fehling’s solution test	+ ve
Benedict’s test	+ ve
Amino acids
Ninhydrin Test	+ ve
Millons Test	+ ve
Xantoprotein Test	+ ve
Lieberman Burchard Test	+ ve
Salkowski test	+ ve
*Steroids*
Lieberman Test	- ve
*Protein*
Biuret test	- ve

Total Phenolic content estimation (TFC)

The content of total Phenolic compounds (TPC) and to tal tannin content was expressed as mg/100mg of gallic acid equivalent of dry extract sample using the equation obtained from the calibration curve.

S.No.	Conc.	Absorbance
0	0	0
1	25	0.049
2	50	0.093
3	75	0.155
4	100	0.255
5	125	0.315
6	150	0.421

Total flavonoids content estimation (TFC)

Total flavonoids content was calculated as quercetin equivalent (mg/g) using the equation based on the calibration curve:

S.No.	Conc.	Absorbance
0	0	0
1	25	0.119
2	50	0.195
3	75	0.297
4	100	0.387
5	125	0.517
6	150	0.626

Table no: 3 Estimation of Total phenolics and Total flavonoids content

S. No

Extracts

Total phenolic content

(%)

Total flavonoids content

(%)

Hydroalcoholic Extract

0.83

1.11

Results of In vivo Antidiabetic Activity:

Table: 4 Effect of Acacia Nilotica treatment on blood glucose (mg/dl) in normal and diabetic rats

Group	Treatment	Blood glucose (mg/dl)
Group	Treatment	Days 0 Days 8 Days 15
I	Normal	99.6 ±2.36 102.0±5.61 108.1±6.32
II	Diabetic Control	250.1±2.0 265.1±2.11^#280.8±2.80^#
III	Diabetic + Acacia Nilotica (100 mg/kg)	241.0±2.5 211.3±2.16^*208.3±2.0^*
IV	Diabetic+Acacia Nilotica (200 mg/kg)	249.7±2.0 206.4 ±2.17^* 199.3±2.7 ^*
V	Diabetic + Glibenclamide (600µg/kg)	251.1 ±1.9 194.5±2.15^* 186.2 ±3.1^*

Values are expressed as mean±S.E.M (n=6).Values are statistically significant at ^#p<0.001 vs. normal group; *P<0.001, **P< 0.01vs. diabetic control group (One-way ANOVA followed by Tukey’s post hoc test).

Table no 5: Effect of Acacia Nilotica treatment on biochemical parameters in normal and diabetic rats

Group	Treatment	TC (mg/dL)	TG (mg/dL)	Total protein(g/dl)
I	Normal	90.1±1.12	86.16±5.5	8.00±1.0
II	Diabetic Control	191.0±1.00	129.01±10.5	5.92±1.1
III	Acacia Nilotica (100 mg/kg)	117.1±1.12^***	93.12±6.19^***	7.03±1.1^***
IV	Acacia Nilotica (200 mg/kg)	109.2±1.10^***	89.13±8.15^***	7.90±1.0^***
V	Glibenclamide (600µg/kg)	105.2±1.23^***	86.44±6.10^***	8.40±1.0^***

Values are expressed as mean±S.E.M (n=6).Values are statistically significant at ^#p<0.001 vs. normal group; *P <0.001, **P<0.01vs. diabetic control group (One-way ANOVA followed by Tukey’s post hoc test).

DISCUSSION:

STZ is a nitrosourea compound produced by Streptomyces achromogenes, which specifically induces DNA strand breakage in beta-cells causing diabetes mellitus. This leads insulin deficiency which in turns increase the blood glucose level. In our study the Acacia Nilotica leaf extract at the doses 100 and 200 mg/kg showed the significant antihyperglycemic activity lower the blood glucose level significantly and dose dependently in antihyperglycemic condition and may be helpful in antidiabetic study done to assess the safety profile of the plant extract had no adverse effect on hematological parameters. Thus, plant extract can be considered non-toxic when given orally at the dose of 100mg/kg and 200 mg/kg body weight. ²⁸

In our study the biochemical parameters are significantly reduced which may be helpful in diabetic complication. In normal metabolism insulin activates the enzyme lipoprotein lipase and hydrolyses triglycerides and difficiency of insulin results in activation of these enzymes thereby causing hypertriglyceridemia. The repeated administration of Acacia Nilotica leaf extract for a period of 15 days resulted a significant improvement in glycaemic control but also minimizing complication associated with diabetes.

Normal healthy animals showed reduction in body weight. The decrease in weight in diabetes was due to the increased muscle wasting in loss of tissue proteins. In the study the reduction of body weight was administered by extract treatment after 15 days in dose dependent manner. Histological studies of pancrease of diabetic control and Acacia Nilotica treated group indicate that the plant cytoprotective properties^29.

From the study we can conclude that hydroalcohalic extract of Acacia Nilotica leaf have signioficant antidiabetic effect. On acute toxicity studies are safe at the decided dose level. Further studies are required to identify the active constituents.

CONCLUSION:

· The current research concludes that the extracts of leaves of Acacia nilotica, based on acute toxicity studies are safe at the decided dose level of 100 & 200 mg/kg of body weight. Extract showed the significant hypoglycemic activity which may lower the blood glucose level in hyperglycemia condition and may be helpful in antidiabetic study.

· Our study provides a way to study the antidiabetic study of the extract for the development of antdiabetic formulation. In our study the biochemical parameters are significantly reduced which may be helpful in diabetic complication.

· We can say that intake of this plant product may help not only in glycaemic control but also in minimizing the complications associated with diabetes.

· In future the activity of product and in house combination could be checked in other animal models.

FUTURE SCOPE OF THE WORK:

Based on the different studies on different parts of A.nilotica, there is a grim need to isolate and identify new compounds from different parts of the tree, which have possible antimutagenic and cytotoxic activities. Therefore, the spreadilbility of naturally occurring polyphenolic compounds having ability to provide protection against certain types of mutagens and carcinogens is of great importance. ³⁰

The A. nilotica extract was also studied for its possible interaction with serotonin (5-HT) receptors which is associated with hypertension. Furthermore, it contains additional serotonin blocking compounds, which may be further studied for detailed interaction with serotonin receptor subtypes.

The high scavenging property of A. nilotica exhibits high scavenging activity due to presence of phenolic compounds. However, further research is required to identify individual components forming anti-oxidative system and develop their application for pharmaceutical and food industries. Umbelliferone, a potent antioxidant isolated from A. nilotica plant and food derived antioxidants are implicated in the prevention of cancer and aging by destroying oxidative species that initiate carcinogenesis through oxidative damage of deoxyribonucleic acid (DNA) The supplementation of functional food with antioxidants, which inhibit the formation of free radicals, can lead to prevention of some diseases As most of the antimu- tagenic compounds act via scavenging of free radicals, There is intense need to investigate the antioxidant activity of the functional components present in the extract from A. nilotica. ³¹

Literature is however scarce in respect of the efficacy of gallotannins as antiplasmodial agents so more investigation is required. Having potential uses of this plant, it is highly recommended to cultivate widely to get maximum production for welfare of mankind.

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Received on 16.08.2018 Accepted on 19.09.2018

Asian J. Pharm. Tech. 2018; 8 (4):231-243.

DOI: 10.5958/2231-5713.2018.00036.3

Agent	Mechanism	Advantages	Disadvantages
Sulfonylurea (glyburide, glimepiride, glipizide)	Stimulating insulin release by pancreatic beta cells by inhibiting the KATP channel	Inexpensive Fast onset of action No effect on blood pressure. No effect on low density lipoprotein lower risk of gastrointestinal problems with metformin more convenient dosing	Causes an average of 5–10 pounds weight gain. Increased risk of hypoglycemia. Glyburide has increases risk of Hypoglycemia. Slightly more as compared with glimepiride and glipizide. Higher risk of death compared with metformin.
Metformin	Acts on the liver to reduce gluconeogenesis and causes a decrease in insulin resistance via increasing AMPK signalling.	Not associated with weight gain Low risk of hypoglycemia as compared to alternatives Good effect on LDL cholesterol Decreases triglycerides No effect on blood pressure Inexpensive	Increased risk of gastrointestinal problems Contraindicated for people with moderate or severe kidney disease or heart failure because of risk of lactic acidosis due to Alcoholism Increased risk of Vitamin B12 deficiency. Less convenient dosing. Metallic taste
Alphaglucosidase inhibitor (acarbose, miglitol, voglibose)	Reduces glucose absorbance by acting on small intestine to cause decrease in production of enzymes needed to digest carbohydrates	Slightly decreased risk of hypoglycemiam as compared to sulfonylurea not associated with weight gain decreases triglycerides no effect on cholesterol	less effective than most other diabetes pills in decreasing glycated hemoglobin increased risk of GI problems than other diabetes pills except metformin inconvenient dosing expensive
Thiazolidinedione (Pioglitazone, Rosiglitazone)	Reduce insulin resistance by activating PPARγ in fat and muscle	Lower risk of hypoglycemia Slight increase in high density ipoprotein Actos linked to decreased triglycerides Convenient dosing	increased risk of heart failure causes an average of 5–10 pounds weight gain associated with higher risk of edema associated with higher risk of anemia increases low density lipoprotein Avandia linked to increased triglycerides and risk of heart attack.