FREE RADICAL SCAVENGING AND HYPOGLYCEMIC POTENTIAL OF CENTRATHERUM ANTHELMINTICUM

FREE RADICAL SCAVENGING AND HYPOGLYCEMIC POTENTIAL OF CENTRATHERUM ANTHELMINTICUM

Daksh Bhatia¹* and Sarvesh Kumar Paliwal²

Department of Pharmacognosy ¹, KIET School of Pharmacy, Ghaziabad – 201206, U.P., India

Head, Department of Pharmacy ², Banasthali University, P.O. Banasthali Vidyapith, Distt. Tonk, Rajasthan-304022, India

ABSTRACT:  Diabetes mellitus (DM) is a complex metabolic disease characterized by chronic hyperglycaemia commonly associated with oxidative stress. The current study aims at assessing the antioxidant and antidiabetic potential of various concentrations of hydroalcoholic extract of Centratherum anthelminticum. The in vitro antioxidant activity was assessed using 1,1-Diphenyl-2-picrilhydrazyl (DPPH), nitric oxide, hydroxyl ion and hydrogen peroxide for free radical scavenging properties of the extracts, and determining their phenol and flavanoid contents. The antidiabetic activity was tested in rats following streptozotocin diabetes induction. The in vitro antioxidant activity using DPPH, nitric oxide radical, hydroxyl radical and H₂O₂ radical showed IC₅₀ value 68.27 ± 0.34, 82.05 ± 0.46, 113.49 ± 0.86 and 94.71 ± 0.78  μg/ml respectively. The hydroethanol extract of plant seed (250, 500 and 750 mg/Kg) exhibited significant antidiabetic activities with 40.46%, 56.37% and 52.15% glycaemia reduction, respectively. These findings suggest that C. anthelminticum seeds possess both antidiabetic and antioxidant properties, and therefore could be used as starting point for the development of herbal medicines and/or source of new drug molecules against diabetes.

Antioxidant, Diabetes, Oxidative stress, Hypoglycaemic activity, Centratherum anthelminticum

INTRODUCTION: Diabetes mellitus is a complex metabolic disorder characterized as state in which homeostasis of carbohydrate and lipid metabolism is improperly regulated. Type 2 diabetes accounts for 90–95% of all cases of diabetes. The main pathophysiological defect of type 2 diabetes is insulin resistance, a decrease in cellular response to insulin.

Type 2 diabetes is manifested when pancreatic beta cells fail to compensate for chronic elevated blood glucose due to dysregulation of insulin-stimulated glucose uptake in the peripheral tissues^{1, 2}.

The impaired metabolism is often accompanied with excessive release of free radicals through lipid peroxidation, due to alteration of the activity of several proteins ³, aggravated by a drastic drop in antioxidant immune mechanisms ⁴. This imbalance generally lead to oxidative stress which is the main factor associated with the severity and death in diabetes. Diabetes mellitus is a major cause of disability, figuring among the top ten killers worldwide ⁵.

Conflicting results have been reported for the role of oxidative stress in diabetes. F2-isoprostanes are prostaglandin like compounds formed in-vivo from free radical catalyzed peroxidation of arachidonic acid and have emerged as novel and direct measures of oxidative stress. F2-isoprostane levels have been reported to be increased in the plasma of type 2 diabetes mellitus and in the urine of type 2 and type 1 diabetic subjects ^{6, 7}. A correlation between impaired glycemic control and enhanced lipid peroxidation has been reported ⁷.

However, lack of correlation between glycemic control and levels of 8-iso-PGF2a or MDA has been shown in another a study ⁸. It was shown that oxidative stress exists in diabetic patients as evidenced by increased total antioxidant capacity in saliva and blood of patients ⁹. Oxidative stress is increased in diabetes because of multiple factors. Dominant among these factors is glucose autoxidation leading to the production of free radicals. Other factors include cellular oxidation/reduction imbalances and reduction in antioxidant defenses (including decreased cellular antioxidant levels and a reduction in the activity of enzymes that dispose of free radicals).

In addition, levels of some prooxidants such as ferritin and homocysteine are elevated in diabetes. Another important factor is the interaction of advanced glycation end products (AGEs) with specific cellular receptors called AGE receptors (RAGE). Elevated levels of AGE are formed under hyperglycemic conditions. Their formation is initiated when glucose interacts with specific amino acids on proteins forming a compound that then undergoes further chemical reactions. Glycation of protein alters protein and cellular function, and binding of AGEs to their receptors can lead to modification in cell signaling and further production of free radicals ¹⁰.

Centratherum anthelminticum Kuntz (Hindi- Kalijiri) previously known as Vernonia anthelmintica belongs to family Compositae. It has a good anthelmintic property and used for the treatment of various skin infections. It is also reported to be used in asthma, kidney troubles, cough and also used to remove blood from liver. The major classes of chemical constituent present in this plant are glycosides, carbohydrates, phenolic compounds and tannins, flavanoids, proteins, saponins, sterols, lipids and fats.^{11, 12}

In this work the effect of its aqueous-alcoholic extract on the blood glucose lowering effect of streptozocin induced diabetic rats has been investigated, which is one of the main parameter for checking the potential of drug in the management of Diabetes mellitus. Furthermore antioxidant potential of the plant extract has also been assessed by various in-vitro models.

MATERIAL AND METHODS: 

Plant collection and extraction:

The dried seeds of CA were purchased from the local market of Delhi and authenticated by ‘Dr. H.B. Singh, Head, Raw Material, Herbarium and Museum’, NISCAIR, New Delhi, and sample was submitted in the museum. Shade dried seeds were defatted with petroleum ether and then extracted with 1:1 mixture of distilled water and ethanol using triple maceration process. The crude extract was evaporated at reduced pressure in rotary film evaporator and dried further in vaccume dessicator with phosphorus pentaoxide (named CAE). The dose of 250 mg/kg, 500 mg/kg and 750 mg/kg were selected with reference to previous literature. The extract was suspended in 5% Tween 80 solution for oral administration.¹³

Animals:

The animals were kindly provided by the Animal House of the KIET School of Pharmacy, Ghaziabad, India. Adult albino rats of either sex weighing 150-200 gm were used for the study. They were housed in polypropylene cages, per cage, with free excess to standard laboratory diet and water. The rats were maintained under standard laboratory condition at 25± 2°C, relative humidity 50 ± 15% and normal photo period (12h dark/12h light) were used for experiment. The entire experimental protocol was approved by the institutional animal ethics committee, KIET School of Pharmacy, Ghaziabad, India.

 Phytochemical screening:

The alcoholic extracts obtained were subjected to preliminary phytochemical screening, to identify the chemical constituents. The methods of analysis employed were those described by Harbone and Trease.^{14, 15}

Oral glucose tolerance test (OGTT):

Rats were fasted overnight and divided into three groups with 6 animals in each group. Group-I received distilled water, to serve as control. Group-II animals were treated with glibenclamide (5 mg/kg, per os) to serve as a standard. Group-III animals were treated with plant extract. The control, standard and test groups were treated with drugs 30 minutes prior to a glucose load (2.5 g/kg, per os). Blood samples were collected at 15, 30, 45, 60, 75, 90 and 120 minutes after glucose loading. Serum was then separated and glucose levels measured immediately.¹⁶

Induction of experimental diabetes:

The amimals were allowed to fast for 18 hr and a freshly prepared solution of streptozotocin (STZ) (55 mg/kg, i.p.) in 0.1 M citrate buffer, pH 4.5 was injected in volume of 1 ml/kg body wt ¹⁷. After 48 hr of STZ administration, rats with moderate diabetes having glycosouria and hyperglycemia (i.e., with blood glucose of greater than 200 mg/dl) were used for the experiment.

Experimental design:

In the experiment, a total of 36 rats (30 diabetic surviving rats, 6 normal rats) were used. The rats were divided in to 6 groups of 6 rats each. Group I untreated rats receiving vehicle (5% tween 80 in distilled water) designated as control. Group II with STZ treatment alone was considered as diabetic control. Group III, IV and V with diabetic rats, were dedicated to plant extract dose of 250, 500 and 750 mg/kg body wt respectively. Group VI receiving glibenclamide (5 mg/kg body wt, p.o.) was designated as standard. The rats received due course of doses once a day for seven days. The fasting blood glucose was taken for all rats once daily in the morning hours.

 Determination of blood glucose level:

The estimation of blood glucose level was done by using one touch glucometer (Accu check sensor) for which a drop of blood was taken from the tail vein.

 Estimation of total flavanoids and Phenols:

Aluminum chloride colorimetric method was used for flavonoids determination ¹⁸. Each plant extracts (0.5 ml of 1:10 g ml-1) in methanol were separately mixed with 1.5 ml of methanol, 0.1 ml of 10% aluminum chloride, 0.1 ml of 1 M potassium acetate and 2.8 ml of distilled water.

It remained at room temperature for 30 min; the absorbance of the reaction mixture was measured at 415 nm with a double beam Shimadzu UV/Visible spectrophotometer (Japan). The calibration curve was prepared by preparing quercetin solutions at concentrations 12.5 to 100 g ml^-1 in methanol.

Total phenols were determined by Folin Ciocalteu reagent ¹⁹. A dilute extract of each plant extract (0.5 ml of 1:10 g ml-1) or gallic acid (standard phenolic compound) was mixed with Folin Ciocalteu reagent (5 ml, 1:10 diluted with distilled water) and aqueous Na₂CO₃ (4 ml, 1 M). The mixtures were allowed to stand for 15 min and the total phenols were determined by colorimetry at 765 nm. The standard curve was prepared using 0, 50, 100, 150, 200, 250 mg L-1 solutions of gallic acid in methanol: water (50:50, v/v). Total phenol values are expressed in terms of gallic acid equivalent (mg g –1 of dry mass), which is a common reference compound.

DPPH radical scavenging assay:

The stable 1, 1-diphenyl-2-picryl hydrazyl radical (DPPH) was used for determination of free radical-scavenging activity of the extracts ²⁰. Different concentrations of each extract were prepared in distilled water, 30 μL of each solution mixed with 1 mL of ethanol solution of DPPH (0.1 mM) and incubated for 30 min in the dark. BHA was used as standard for this assay. At the end of this period, the absorbance was recorded at 517 nm using a spectrophotometer, and the antiradical activity of each concentration calculated as percentage reduction of DPPH concentration, with reference to the optical density at the start, as followed:

% scavenged [Free radicals] = [(Ao − A₁)/Ao] × 100 where

Ao was the absorbance of the control and A₁ was the absorbance in the presence of the sample of extract or standard.

Nitric oxide radical scavenging activity:

Nitric oxide scavenging activity was measured spectrophotometrically²¹. Extract, prepared in ethanol, was added to different test-tubes in varying concentrations. Sodium nitroprusside (5mM) in phosphate buffer was added to each test tube to make volume up to 1.5ml. Solutions were incubated at 25ºC for 30 minutes. Thereafter, 1.5ml of Griess reagent (1% sulphanilamide, 0.1% naphthylethylenediamine dichloride and 3% phosphoric acid) was added to each test tube. The absorbance was measured, immediately, at 546 nm and percentage of scavenging activity was measured with reference to ascorbic acid as standard.

Inhibition of hydroxyl radical:

Hydroxyl radical scavenging activity of seed extract was assayed by the established method²². The reaction mixture 3.0 ml contained 1.0 ml of 1.5 mM FeSO4, 0.7 ml of 6 mM hydrogen peroxide, 0.3 ml of 20 mM sodium salicylate and varied concentrations of the extracts. After incubation for 1 hour at 37°C, the absorbance of the hydroxylated salicylate complex was measured at 562 nm. The scavenging activity of hydroxyl radical effect was calculated as follows : [1‐(A₁‐A₂) / A₀] x 100, where A₀ is absorbance of the control (without extract) and A₁ is the absorbance in the presence of the extract, A₂ is the absorbance without sodium salicylate.

Hydrogen peroxide scavenging activity:

The ability of extract to quench hydrogen peroxide (H₂O₂) was determined spectrophotometrically. Different concentrations of extract or ascorbic acid were dissolved in 3.4mL of 0.1M (pH 7.4) of phosphate buffer solution and mixed with 0.6mL of 40mM solution of H₂O₂. Absorbance of H₂O₂ at 230 nm was determined 10 minutes later in a spectrophotometer. For each concentration, a separated blank sample was used for background subtraction.²³

Reductive ability:

Various concentrations of extract of (1ml) were mixed with 2.5 ml of 1% sodium phosphate buffer (pH 6.6) and 2.5 ml of 1% potassium ferricyanide. Then the mixture was incubated at 50°C for 30 min. After 2.5 ml of 10% TCA were added to the mixture was centrifuged at 3,000 rpm for 10 min. The upper layer (2.5 ml) was mixed with 2.5 ml deionized water with 0.5 ml of 0.1% of ferric chloride and the absorbance was measured at 700 nm ²⁴.

Statistical analysis:

Results were expressed as mean±S.E.M. Data were statistically analyzed by one-way ANOVA, followed by Tukey's multiple comparison test, with the level of significance set at P<0.05, P<0.01 and P<0.001.

 RESULTS AND DISCUSSION:

Phytochemical profile:

The defatted hydroalcoholic extract of the plant material yield (16.17%). The phytochemical analysis of the extract revealed the presence of a diversity of chemical families, including flavonoids, terpenes, sterols, saponins, alkaloids and polyphenols. However, lipids were very less in the extract.

Effect of Centratherum anthelminticum on serum glucose in normal fasted rats:

In the control groups a significant increase in blood glucose levels was noticed up to 90 minutes which was followed by a reduction after 90 minutes to 120 minutes (Table 1). Treatment with the standard drug glibenclamide (group-III), blood glucose rose at 30 minutes followed by subsequent fall up to 120 minutes. It was observed from the present study that the administration of CAE increased the glucose levels up to 60 minutes. A significant reduction in the blood sugar level was observed in the tested groups when compared with control group.

TABLE 1: EFFECT OF CA EXTRACT ON SERUM GLUCOSE IN NORMAL FASTED RATS

Values are means ± S.E.M.

P<0.05 as compared with control are considered significant

Hypoglycemic effect:

The management of diabetes is more concerning inspite of its treatment. Many synthetic drugs are in the flow for its management but due to side effects, attention toward herbal treatment is increasing day by day. The effect of extract of seeds were studied on rats for antidiabetic effect. The doses used were 250, 500 and 750 mg/kg body wt. All the doses were showed marked decrease in the blood glucose level during the study of one week. The standard drug used for the comparison was glibenclamide which showed 59.58% decrease in the blood glucose level. 250 mg dose showed 40.46% decrease, 500 mg dose showed 56.37% and 750 mg dose showed 52.15% decrease in the blood glucose level within one week and there comparisons are presented graphically (Figure 1).

In Diabetic controlled group rats there was no significant decrease in the blood glucose level. Simultaneously general behavior of the animals were also recorded during the study and it was found that complications during diabetes like thirst, fatigue, irritation etc. were very less in the animals feed with herbal drug in comparison to diabetic controlled rats and rats which received glibenclamide.

FIGURE 1: EFFECT OF CAE ON SERUM BLOOD GLUCOSE LEVEL IN STZ INDUCED DIABETIC RATS FOR 7 DAYS

Values are means ± S.E.M.

P<0.001 as compared with control are considered significant

Total phenolic and flavonoid content:

Phenolic compounds are secondary plant metabolites, which contribute to the overall antioxidant activities of plants mainly due to their redox properties.

The total phenolic content of CA extract was determined by Folin-Ciocalteu assay using gallic acid as a standard phenolic compound. The extract had the phenolic content (512.8 ± 21.2 mg GAE g-1), which may have contributed towards its radical scavenging activity in both DPPH and nitrc oxide radical scavenging assay.

The content of total flavanoids was also measured spectrophotometrically by using the aluminium chloride colorimetric assay. The flavonoid content of CA was expressed as quercetin equivalents in mg/g dry weight (48.6 ± 2.1 mg/g dry weight) and a calibration curve of quercetin was used.

 DPPH radical scavenging activity:

In the DPPH test, the stable, nitrogen centered, coloured, DPPH free radical is reduced either by hydrogen donor or antioxidant to a non-radical DPPH-H and the decrease in colour of DPPH radical is monitored over a time period ²⁵. The extract showed a sharp drop in DPPH colour intensity, indicating high antioxidant activity in quenching DPPH radicals. The DPPH radical scavenging potential of various concentrations of extracts and BHA are presented in Figure 2. The synthetic antioxidant showed highest DPPH radical scavenging activity among the tested samples with an IC₅₀ value of 8.1 ± 0.26 μg/ml. The IC₅₀ value of the plant extract was found to be 68.27 ± 0.34 μg/ml.

 Nitric oxide radical scavenging activity:

Extracts of CA revealed the significant presence of antioxidative agents like flavonoids and tannins. Nitric Oxide (NO) scavenging assay is based on the scavenging ability of the extracts as well as ascorbic acid, which is used as standard. The scavenging of NO was found to increase in dose dependent manner. At the maximum concentration, inhibition was found to be 85.66% for ascorbic acid, which serves as the standard. For plant extract, inhibition was found to be 79.28% (Figure 2) and the IC₅₀ value 82.05 ± 0.46 μg/ml.

 Inhibition of hydroxyl radical:

The hydroxyl radical is the most reactive of the reactive oxygen species, and it induces severe damage in adjacent biomolecules ²⁶. The hydroxyl radical can cause oxidative damage to DNA, lipids and proteins²⁷. The hydroxyl radical scavenging activity of CA extract was assessed by its ability to compete with salicylic acid for hydroxyl radicals in the hydroxyl generating/detecting system. In the present study, the hydroxyl radical‐scavenging effect of the CA extract at maximum concentration was found to be 65.54% (Figure 2). The IC₅₀ value was found to be 113.49 ± 0.86 µg/ml. Hence, the CA extract can be considered as a good scavenger of hydroxyl radicals.

Hydrogen peroxide scavenging activity:

Scavenging activity of hydrogen peroxide in CAE (200 μg) and BHT (50 μg) as reference compound was not remarkably different and shown to be 79 % and 72 % at initial time respectively (Figure 2). The composition of hydrogen peroxide into water may occur according to the antioxidant compounds as the antioxidant component present in the extract is good electron donors, they may accelerate the conversion of H₂O₂ to H₂O. The IC₅₀ value was found to be 94.71 ± 0.78 μg/ml.

FIGURE 2: EFFECT OF CAE ON VARIOUS IN-VITRO FREE RADICAL MODELS

 Reductive ability:

The reducing power of a compound is associated with electron donating capacity and serves as an indicator of antioxidant activity^{28, 29}. The ability of CA extracts to reduce ferric to ferrous was determined and compared with that of a standard BHA and ascorbic acid. At all concentrations extract exhibited lower activity than the standards. (Table 2)

 TABLE 2: REDUCING ABILITY OF CA EXTRACT

Values are mean ± SEM of 3 replicates

Diabetes is a prevalent systemic disease affecting a significant proportion of the population worldwide. The effects of diabetes are devastating and well documented. There is increasing evidence that in certain pathologic states, especially chronic diseases, the increased production and/or ineffective scavenging of reactive oxygen species (ROS) may play a critical role. High reactivity of ROS determines chemical changes in virtually all cellular components, leading to lipid peroxidation. Production of ROS and disturbed capacity of antioxidant defense in diabetic subjects have been reported.

It has been suggested that enhanced production of free radicals and oxidative stress is central event to the development of diabetic complications. This suggestion has been supported by demonstration of increased levels of indicators of oxidative stress in diabetic individuals suffering from complications. Therefore, it seems reasonable that antioxidants can play an important role in the improvement of diabetes. There are many reports on effects of antioxidants in the management of diabetes.

The effect of C.anthelminticum was studied for the management of diabetes mellitus. Streptozotocin has been observed to cause a massive destrution of the β – cell of the islets of langerhans and induce hyperglycemia. The perusal of literature shows that studies were carried out on this plant with regard and has some scientific evidence for antidiabetic activity. The plant is credited with flavones glyosides, which in general believed to be responsible for antidiabetic activity. The possible mechanism by which C.anthelminticum brings about its hypoglycemic action may be potentiating the insulin effect of plasma by increasing either the pancreatic secreation of the insulin from the β-cell of islets of langerhans or its release from bound insulin.

DPPH is a relatively stable free radical and the assay determines the ability of CAE to reduce the radical to the corresponding hydrazine by converting the unpaired electrons to paired ones, which infect is the action of the antioxidants. The dose dependent inhibition of DPPH radical (Fig 2) indicates that CAE causes reduction of DPPH radical in a stoichometric manner³⁰.

Nitric oxide (NO) is an important chemical mediator generated by endothelial cells, macrophages, neurons etc and is involved in the regulation of various physiological processes. Excess concentration of NO is associated with several diseases. Oxygen reacts with the excess nitric oxide to generate nitrite and peroxy nitrite anions, which act as free radicals ³¹. In the present study the extract competes with oxygen to react with nitric oxide and thus inhibits the generation of the anions.

A substance may act as an antioxidant due to its ability to reduce ROS by donating hydrogen atom. The reducing property of CAE (Table 2) implies that it is capable of donating hydrogen atom in a dose dependent manner. The high content of phenolic compounds in the extract may be a contributing factor towards antioxidant activity because the phenolic compounds are known to have direct antioxidant property due to the presence of hydroxyl groups, which can function as hydrogen donor.

Preliminary phytochemical analysis shows the presence of tannins and flavonoids in CAE which are well known. Thus the antioxidant potential of Centratherum anthelminticum extract could be attributed due to the presence of polyphenolic compounds.

 REFERENCES:

1. Taheri E, Djalali M Fau - Saedisomeolia A, Saedisomeolia A Fau - Moghadam AM, Moghadam Am Fau - Djazayeri A, Djazayeri A Fau - Qorbani M and Qorbani M: The relationship between the activates of antioxidant enzymes in red blood cells and body mass index in Iranian type 2 diabetes and healthy subjects. (2251-6581).
2. Amiram M, Luginbuhl KM, Li X, Feinglos MN and Chilkoti A: A depot-forming glucagon-like peptide-1 fusion protein reduces blood glucose for five days with a single injection. J Control Release 2013;172(1):144-51.
3. Lekshmi RK, Divya BT and Mini S: Cissus quadrangularis extract attenuates hyperglycaemia-mediated oxidative stress in streptozotocin-induced diabetic rats. Redox report : communications in free radical research 2014;19(5):214-20.
4. Zatalia SR and Sanusi H: The role of antioxidants in the pathophysiology, complications, and management of diabetes mellitus. Acta Med Indones 2013;45(2):141-7.
5. Babizhayev MA, Lankin VZ, Savel'Yeva EL, Deyev AI and Yegorov YE: Diabetes mellitus: novel insights, analysis and interpretation of pathophysiology and complications management with imidazole-containing peptidomimetic antioxidants. Recent Pat Drug Deliv Formul 2013;7(3):216-56.
6. Gopaul NK, Anggard EE, Mallet AI, Betteridge DJ, Wolff SP and Nourooz-Zadeh J: Plasma 8-epi-PGF2 alpha levels are elevated in individuals with non-insulin dependent diabetes mellitus. FEBS letters 1995;368(2):225-9.
7. Bajaj S and Khan A: Antioxidants and diabetes. Indian J Endocrinol Metab 2012;16(Suppl 2):S267-71.
8. Rani AJ and Mythili SV: Study on total antioxidant status in relation to oxidative stress in type 2 diabetes mellitus. J Clin Diagn Res 2014;8(3):108-10.

9. Astaneie F, Afshari M, Mojtahedi A, Mostafalou S, Zamani MJ, Larijani B, et al: Total antioxidant capacity and levels of epidermal growth factor and nitric oxide in blood and saliva of insulin-dependent diabetic patients. Arch Med Res 2005;36(4):376-81.
10. Penckofer S, Schwertz D and Florczak K: Oxidative stress and cardiovascular disease in type 2 diabetes: the role of antioxidants and pro-oxidants. J Cardiovasc Nurs 2002;16(2):68-85.
11. Bhatia D, Gupta M, Bharadwaj A, Pathak M, Kathiwas G and Singh M: Anti-diabetic activity of Centratherum anthelminticum kuntze on alloxan induced diabetic rats. Pharmacologyonline 2008(3):1-5.
12. Bhatia D, Kumar M, Gupta A, Singh M and Kaithwas G: Pharmacognostical studies on seeds of Centratherum anthelminticum Natural Product Radiance 2008;7(4):4.
13. Banihashem A, Ghasemi A, Ghaemi N, Moazzen N and Amirabadi A: Prevalence of transient hyperglycemia and diabetes mellitus in pediatric patients with acute leukemia. Iran J Ped Hematol Oncol. 2014;4(1):5-10.
14. Harborne JB, Baxter H and Moss GP: Phytochemical dictionary : a handbook of bioactive compounds from plants. Philadelphia: Taylor & Francis, 2nd ed. London 1999.
15. Evans WC, Trease GE and Evans D: Pharmacognosy. Edinburgh, New York: WB Saunders, 15th ed.2002.
16. Zhang H, Zhao D, Shen J, Zhou X, Chen W and Jiang S: Evaluation of oral glucose tolerance test, beta-cell function and adverse obstetric outcomes. Biomedical reports 2013;1(5):807-11.
17. Sharma B and Singh N: Pitavastatin and 4'-hydroxy-3'-methoxyacetophenone (HMAP) reduce cognitive dysfunction in vascular dementia during experimental diabetes. Current neurovascular research 2010;7(3):180-91.
18. Sen S, De B, Devanna N and Chakraborty R: Total phenolic, total flavonoid content, and antioxidant capacity of the leaves of Meyna spinosa, an Indian medicinal plant. Chinese journal of natural medicines 2013;11(2):149-57.
19. Hendrychova H, Vildova A, Kocevar-Glavac N, Tumova L, Kanybekovna EA and Tuma J: Antioxidant activity and phenolic content of Bergenia crassifolia, B. x ornata and B. ciliata. Natural product communications 2014;9(4):519-22.
20. Chen Z, Bertin R and Froldi G: EC50 estimation of antioxidant activity in DPPH. assay using several statistical programs. Food chemistry 2013;138(1):414-20.
21. Govindarajan R, Rastogi S, Vijayakumar M, Shirwaikar A, Rawat AK, Mehrotra S, et al: Studies on the antioxidant activities of Desmodium gangeticum. Biological & pharmaceutical bulletin 2003;26(10):1424-7.
22. Santos PM, Antunes AM, Noronha J, Fernandes E and Vieira AJ: Scavenging activity of aminoantipyrines against hydroxyl radical. European journal of medicinal chemistry 2010;45(6):2258-64.
23. Kaithwas G, Singh P and Bhatia D: Evaluation of in vitro and in vivo antioxidant potential of polysaccharides from Aloe vera (Aloe barbadensis Miller) gel. Drug Chem Toxicol 2014;37(2):135-43.
24. Yin J, Heo SI and Wang MH: Antioxidant and antidiabetic activities of extracts from Cirsium japonicum roots. Nutrition research and practice 2008;2(4):247-51.
25. Xie J and Schaich KM: Re-evaluation of the 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) assay for antioxidant activity. Journal of agricultural and food chemistry 2014;62(19):4251-60.
26. Gutteridge JM: Reactivity of hydroxyl and hydroxyl-like radicals discriminated by release of thiobarbituric acid-reactive material from deoxy sugars, nucleosides and benzoate. The Biochemical journal 1984;224(3):761-7.
27. Spencer JP, Jenner A, Aruoma OI, Evans PJ, Kaur H, Dexter DT, et al: Intense oxidative DNA damage promoted by L-dopa and its metabolites. Implications for neurodegenerative disease. FEBS letters 1994;353(3):246-50.
28. Siddhuraju P, Mohan PS and Becker K: Studies on the antioxidant activity of Indian Laburnum (Cassia fistula): a preliminary assessment of crude extracts from stem bark, leaves, flowers and fruit pulp. Food chemistry 2002;79(1):61-7.
29. Yen GC, Duh PD and Tsai CL: Relationship between antioxidant activity and maturity of peanut hulls. Journal of agricultural and food chemistry 1993;41(1):67-70.
30. Sánchez-Moreno C: Review: Methods Used to Evaluate the Free Radical Scavenging Activity in Foods and Biological Systems. Food Science and Technology International 2002;8(3):121-37.
31. Sharma B and Singh N: Pharmacological inhibition of inducible nitric oxide synthase (iNOS) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, convalesce behavior and biochemistry of hypertension induced vascular dementia in rats. Pharmacol Biochem Behav 2013;103(4):821-30.
    

    ---

    How to cite this article:

    Bhatia D and Paliwal SK: Free Radical Scavenging and Hypoglycemic Potential of Centratherum Anthelminticum. Int J Pharm Sci Res 2015; 6(4): 1616-23.doi: 10.13040/IJPSR.0975-8232.6(4).1616-23.

    ---

    All © 2013 are reserved by International Journal of Pharmaceutical Sciences and Research. This Journal licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

    ---