INTRODUCTION:

Carissa carandus Linn.(karaunda), common herb of dogbane family Apocynaceae. Carissa carandus Linn. commonly known as Cranberry, Bengal currant, Christ thorn. Recently the name of this plant has changed to Carissa congesta. Carissa carandus Linn. has been found throughout India, Bangladesh, Malaysia, Mayanmar etc. Carissa carandus Linn. has been used as additive in Indian pickles¹. Traditionally, all parts of the plant have been used for treatment of various diseases such as intestinal worms, biliousness, scabies, indigestion².

The biological activities reported from this plant includes analgesic, anti-inflammatory, antipyretic³, hepatoprotective⁴, anticonvulsant⁵, antihelmenthic⁶, antimalarial⁷, cardiotonic⁸, antiulcer⁹, antidiabetic¹⁰, antibacterial¹¹, antihyperlipidemic¹², anticancer¹³, antiviral¹⁴, antifungal, antioxidant activity¹⁵. The phytochemical screening of the plant roots reveals the presence of triterpinoids, flavonoids, carbohydrates, steroids, lignans, saponins, tannins & alkaloids. It is evident from the literature that saponins possess significant memory enhancing potency¹⁶. As the Carissa carandus Linn. contains saponins, the present objective to evaluate Nootropic activity of Carissa carandus Linn. is justifiable.

MATERIAL AND METHOD:

Plant material collection and identification:

The roots of Carissa carandus were collected from campus of Vijaya College of Pharmacy, in Hyderabad and authenticated from a botanist and the sample specimen submitted to Vijaya college of Pharmacy for future reference. The roots were air dried in shade for one week. Then they were subjected to size reduction using high capacity grinding machine to get coarse powder of desired particle size. The weight of the plant powder is 100gms.

Extraction:The coarse powder of roots of Carissa carandus Linn.(100gms) were taken and subjected to successive soxhlet extraction with hexane, methanol and water respectively for 10 hours with each solvent.

Table 1: Extractive values of Carissa carandusLinn.roots

Extracts

Weight of extract

Extractive values %w/w

Hexane extract

Methanol extract

Water extract

2.05grams

1.08grams

3.06grams

2% w/w

1.8% w/w

3.6% w/w

Phytochemical screening:

The roots of Carissa carandus has been qualitatively analysed for various phyto-constituents. Preliminary phytochemical tests were performed for the Carissa carandus Linn. to detect the presence of phytochemicals by following the standard methods described in the practical pharmacognosy of kokate and khandelwal. The results have been tabulated in table 2.

Table 2: Phytochemical screening of Carissa carandus Linn root

S. No	Phytochemicals	Hexane extract	Methanol extract	Water extract
1.	Carbohydrates	-	+	+
2.	Glycosides	-	+	+
3.	Proteins	-	+	+
4	terpenoids	+	+	-
5.	steroids	+	+	+
6.	Lignans	-	+	+
7.	Flavonoids	-	+	+
8.	Coumarins	-	+	+
9.	Phenolic compounds/tannins	-	+	+
10.	Fats and oils	+	-	-

Chemicals and drugs used:

Piracetamwas obtained as a gift sample from Alkem laboratories, Mumbai. Piracetam was suspended in 1% acacia and used for the present studies.

Preparation of drug solution:

Methanolic extract was suspended in the 1%w/v acacia. Piracetam was suspended in 1% w/v acacia and were used for the study.

Animals/ Preparing animals:

Albino rats (150-360 gm) were used for the present research. They were procured from sainath agencies, musheerabad. After randomization into various groups and before initiation of experiment, the rats were acclimatized for a period of 15 days. Animals were housed in polypropylene cages and maintained under standard environmental conditions such as temperature (26 ± 2ºc), relative humidity (45-55%) and 12hr dark/light cycle. The animals were fed with rodent pellet diet (Golden Mohur Lipton India Ltd.) and water ad libitum. The study protocol was approved from the institutional animal ethics committee (IAEC) before commencement of experiment (1292/ac/09/CPCSEA).

Acute toxicity test (Up and Down procedure, OECD guidelines no.425)

Albino rats were selected for the present toxicity study. The rats were treated with doses of 5, 50, 300 and 2000mg/kg and were observed for any signs of toxicity/ mortality for 24 hrs. Toxicity includes symptoms such as drowsiness, ataxia, lachrymal, salivary secretions, disorientation, convulsions, sedation as well as respiratory distress. The rats were observed for the next 14days. Body weights of rats were recorded on 8^th day and 14th day. It was observed that methanolic extract of Carissa carandus Linn. roots was safer in rats at all given doses. Hence 2000 mg/kg was selected as safer dose (LD 50) for our study and a cut off dose i.e 1/10^th of 2000 mg/kgi.e 200mg/kg was confirmed for invivo studies.

Screening of Nootropic activity of Carissa carandus Linn.roots byObject recognition test inrats

The object recognition test chamber fabricated locally consisted of white colored thermocole (70 × 60 ×30 cm). It was illuminated by a 40 W lamp suspended 50 cm above the apparatus. The object to be discriminated was also made of glass in two different shapes of 10 cm height and colored black. On the first day training trial, rats were allowed to explore the box without any object for habituation phase, each animal kept in empty box for 5 minutes. On the second day of test trial of acquisition phase, trial (T1) conducted 5 min after administration of vehicle (10 ml/kg) ormethanolic extract (200 mg/kg) or piracetam (200mg/kg) two identical objects (F, F₁) were presented in opposite corners of the box and the time taken by each rat to complete 5 min of object exploration was recorded (Exploration was considered as directing the nose at a distance less than 2 cm to the object and/or touching with nose).On the second day after exploration phase retention phase (T2) was performed and a new object replaced one of the objects presented in T1i.e F₁replaced with N and rats were left in the box for next 5min. The time spent for exploring the familiar (F) and the new object (N) was recorded separately and discrimination index (D) was calculated as (N-F)/ (N+F). The object was changed randomly and apparatus was cleaned with hydrogen peroxide after each trial to avoid place preference and the influence of olfactory stimuli respectively.

Figure I: Nootropic Activity of Carissa carandus by Object Recognition Test in Rats

STATISTICAL ANALYSIS:

The values are represented as mean ± S.E.M, and statistical significance between treated and control groups was analyzed using One way ANOVA, Followed by Dunnett’s test where P<0.001, P<0.01 and P<0.05 was considered statistically significant.

RESULTS AND DISCUSSION:

Cognitive deficits have long been recognized as severe and consistent neurological disorders associated with numerous psychiatric and neurodegenerative states such as Alzheimer's disease. Dementia is one of the age related mental problem and characteristic symptoms of Alzheimer’s disease. Stressful conditions are often associated with loss of memory and other cognitive functions. Various drugs like diazepam, alcohol, barbiturates disrupt learning and memory. Traditionally herbal drugs have been used to enhance cognitive function. It was observed that discrimination index (an index of memory) with extract treated rats is more compared with control treated rats. This increase in discrimination index with Carissa carandusLinn. roots extract treated rats shows that it has memory enhancing potential. However, the discrimination index, exhibited by extract treated rats was found to be less than piracetam treated rats this shows that methanolic extract of Carissa carandasLinn roots have lesser nootropic effect than standard piracetam. Literature survey and phytochemical evaluation of pant extract reveals the presence of saponins. Hencesaponins present in Carissa carandasLinn roots may be responsible for Memory enhancing effect.

Table 3: Effect of Methanolic extract and Piracetam on discrimination index in object recognition test

S.no	Treatment mg/kg	Discrimination Index
1.	Control	0.0470±0.113
2.	Methanolic extract 200mg/kg	0.2042±0.412
3.	Piracetam	0.6110±0.531

*P< 0.05, **P<0.01, ***P< 0.001was considered statistically significant.

Figure II: Graphical representation of nootropic activity of carissa carandus roots by object recognition test in rats

CONCLUSION:

Based on findings of the current study it is concluded that Carissa carandus Linn (200mg/kg) has significant nootropc activity. Carissa carandus Linn root extract significantly increased discrimination index when compared to control treated rats indicating the enhancement memory in test rats. The exact mechanism behind the nootropic efficacy of Carissa carandus Linn roots is not clear. However it can be assumed that Carissa carandus Linn roots may be involve in the regeneration of cholinergic neurons thereby enhancing the levels of acetyl choline in brain neurons. Further studies are needed to know the exact mechanism behind the nootropic potential of Carissa carandus Linn roots.

ACKNOWLEDGEMENT:

The authors are grateful to management of Vijaya college of pharmacy for providing facilities.

REFERENCES:

1. Kirtikar KR, Basu BD. Indian medicinal plants. LalitMohaBasu, Allahabad. Vol.II, 2003,1546-1549

2. Devumurari V, Shivanand P, Goyani MB, Vaghani S, Jivani NP. A review: Carissa congesta: Phytochemical constituents, traditional use and pharmacological properties. Pharmacogn Rev 2009; 3(6):375.

3. Galipalli, Sindhuja, et al. Activity-guided investigation of Carissa carandas (L.) roots for anti-inflammatory constituents. Natural Product Research 29.17 (2015): 1670-1672.

4. Hegde K, Joshi AB. Hepatoprotective effect of Carissa carandas Linn root extract against CCl₄ and paracetamol induced hepatic oxidative stress. Indian J Exp Biol 2009;47(8):660-7.

5. Hedge K, Thakker SP, Joshi AB, Shastry CS, Chandrashekar KS. Anticonvulsant activity of Carissa carandus Linn. Root extract in experimental mice. Tropical J. of Pharma. Res. 2009;8(2):117-125.

6. Mihra CK, Sasmal D, Shrivastava B. An in vitro evaluation of the anthelminthic activity of unripe fruits extract of Carissa carandus Linn. Int J Drug Dev Res 2012;4(4):393-7.

7. Bapna S, Ramaiya M, Chowdhary A. Antimalarial activity of Carissa carandus Linn. Against Plasmodim faliparam. J Antimicrob (Photon)2013;128:246-50.

8. Rastogi R C ,Vohra M M, Rastogi R P, Dhar M L. 1966.Carissa carandas .I. Isolation of the cardiac-active principles. Indian Journal of Chemistry 4(3):132-8.

9. Merai, Ankit H., and Anil G. Jadhav. Anti ulcer activity of Carissa carandas using root extract in albino rats. World J Pharm Pharm Sci 3.4 (2014): 1314-26.

10. Itankar, Prakash R., et al. Antidiabetic potential of unripe Carissa carandas Linn. fruit extract. Journal of Ethnopharmacology. 135.2 (2011): 430-433.

11. Agarwal, Tarun, et al. In vitro study of antibacterial activity of Carissa carandas leaf extracts. Asian J. Plant Sci. Res 2.1 (2012): 36-40.

12. Sumbul, S., and S. I. Ahmed. Anti-hyperlipidemic activity of Carissa carandas (Auct.) leaves extract in egg yolk induced hyperlipidemic rats. J Basic Appl Sci 8 (2012): 40-50.

13. Sulaiman, Shaida Fariza, et al. Anticancer Study of Carissa carandas extracts. (2008).

14. Taylor, R. S. L., et al. Antiviral activities of medicinal plants of southern Nepal. Journal of Ethnopharmacology. 53.2 (1996): 105-110.

15. Aslam, Farah, et al. Antioxidant, haemolytic activities and GC-MS profiling of Carissa carandas roots. International Journal of Phytomedicine 3.4 (2012): 567-578.

16. Russo, A., and F. Borrelli. Bacopa monniera, A reputed nootropic plant: an overview. Phytomedicine. 12.4 (2005): 305-317.

Received on 06.04.2016 Modified on 10.04.2016

Res. J. Pharmacognosy and Phytochem. 2016; 8(2): 81-84

DOI: 10.5958/0975-4385.2016.00015.7