Evaluation of the antioxidant activity of various extracts of aerial parts of Cassia absus: An in-vitro techniques

Cassia absus (Linn) (family Fabaceae ) is generally known as “chaksu ” inan ayurvedic traditional system. The current study, aerial parts of different concentrates (Pet.ether, ethyl acetate and methanol) of Cassia absus, was evaluated for its in-vitro antioxidant potential by Diphenylpicrylhydrazyl radical, nitric oxide activity and total antioxidant activity taking ascorbate as the standard for all the three methods. The IC50 value was originated that methanolic concentrates of Cassia absus more ef icient in Diphenylpicrylhydrazyl radical, nitric oxide activity, total antioxidant activity compared EA&PE concentrates.The methanolic concentrates of Cassia absus & ascorbic acid exhibited antioxidant potential possessing IC50230μg/ml&130μg/ml (Nitric oxide). 205μg/ml &57μg/ml (total antioxidant),195μg/ml & 66μg/ml (Diphenylpicrylhydrazyl radical)respectively. The difference in the scavenging potential of the extracts can be due to variation in the percentage of bioactive compounds present in different solvents. In vitro antioxidant studies obviouslyshow the methanolic concentrates of Cassia absushave better antioxidant activity. This result indicates that aerial parts of methanolic concentrates Cassia absuscould serve as a natural antioxidant, whichmay be useful in prevent free radical-induced diseases.


INTRODUCTION
Oxygen is a highly reactive molecule that damages living organisms by producing reactive oxygen species(ROS) (Davies, 1995). Investigational con irmation suggests that free radicals (FR) and ROS have been concerned in a more number of disorders (Niwa, 1991;Richards and Sharma, 1991).
Oxidative stress ensuing from the poisonous effects of free radicals on the tissue plays a signi icant role in the pathogenesis of a variety of pathological conditions such as ageing process, anemia, arthritis, asthma, atherosclerosis, cancer, neuro degeneration, Parkinson's disease, and perhaps dementia. Antioxidants are radical scavengers, which protect the human body against freeradicals (Mahakunakorn et al., 2004;Polterait, 1997). Ethnomedical literature contains a huge amount of herbs that may be used for the various diseases, in which ROS and free radical participate vital responsibility. Huge numerical herbs are used for strong antioxidant activity (Badami et al., 2003). Current reports revealed that there is a converse connection between the intake of antioxidant-rich foods and the occurrence of human diseases (Halliwell and Gutteridge, 1999).
Cassia absus(Linn) (family Fabaceae ) is generally known as "chaksu" in an ayurvedic traditional sys-tem. (Kirtikar and Basu, 1918). Chaksine and iso chaksine bothalkaloids were isolated from the seed of Cassia absus (Siddiqui and Ahmed, 1935). Cassia absus was used for different diseases like antibacterial, antimalarial and lowering the blood pressure (Aftab et al., 1996). Cassia absus was used antihistaminic activity of an eye drops (Abdul et al., 2010). Still, no literature are available on the antioxidant activity of aerial parts Cassia absus. Thus, the present study to assess antioxidant activities of aerial parts Cassia absus.

Gathering & Identi ication of Plant
The aerial parts Cassia absus(family Fabaceae) were gathered form senkottai, Tirunelveli District of Tamilnadu, India.
Plant identi ication was made from the Botanical investigation of India, Palayamkottai.

Preparation of Concentrates
The pulverized materials were packed in a muslin cloth and extracted with pet.ether, ethyl acetate and methanol as solvents respectively according to the (Shajiselvin et al., 2010) increasing order of polarity through hot constant percolation method in Soxhlet equipment (Harborne, 1984) for twentyfour hours. The concentrates were concentrated through the rotational evaporator and subjected to solidify drying in a lyophilizer till dry powder was acquired (Alagumanivasagam et al., 2010;Sivakrishnan et al., 2014).

Assessment of Antioxidant potential through in vitro methods
The variety of concentrates of Cassia absus were used assessment of antioxidant activity by Mensor et al. (2001) method was adopted for Diphenyl picrylhydrazyl radical assay, Garrat et al. (1964) method was adopted for NO radical assay & Prieto et al. (1999) method described for total antioxidant activity.

DPPH scavenging activity
Diphenylpicrylhydrazylis a stable N 2 -centered free radical generally utilized for testing the antioxidant potential of herbal concentrates. When the stable Diphenylpicrylhydrazyl radical accepts an electron from the antioxidant compound, the violet colour of the Diphenylpicrylhydrazyl as reduced to yellow colored diphenylpicrylhydrazine radical which was measured colorimetrically. Substances which are able to perform this reaction can be considered as antioxidants &, therefore, radical scavengers (Mohammad et al., 2009). The DPPH activity of PE concentrates of Cassia absus appeared in Table 1. The PE concentrates of Cassia absus exhibit a more DPPH activity of 49.16% at 800 µg/ml & ascorbate was recorded 72.82% at 800 µg/ml. The IC 50 of the PE concentrates of Cassia absus & ascorbic acid were recorded 825µg/ml & 66µg/ml correspondingly.
DPPH activity of EA concentrates of Cassia absus summarized in Table 2. The EA concentrates of Cassia absus exhibit more DPPH scavenging potential of 55.76% at 800 µg/ml & ascorbate was recorded 72.82% at 800 µg/ml. The IC 50 of the EA concentrates of Cassia absus & ascorbic acid were recorded590µg/ml& 66µg/m correspondingly.
The methanolic concentrates of Cassia absus was recorded to more activity than PE&EA concentrates. The IC 50 of the methanolic concentrates of Cassia absus & ascorbic acid were found to be 195 µg/ml& 66 µg/ml correspondingly. Among the three different plant concentrates tested, interestingly, in the DPPH radical activity of the methanolic of Cassia absus having more Diphenylpicrylhydrazyl radical potential comparable with that of ascorbic acid.

Nitric oxide scavenging activity
NO produced from sodium nitroprusside reacts with oxygen to form nitrite. The nitrite ions diazotize with sulphanilamide acid and couple with naphthyl ethylenediamine, producing pink coloured, which absorbs at 546 nm (Panda et al., 2009). Nitric oxide scavenging activity of PE concentrates of Cassia absus appeared in Table 4. The PE concentrates of Cassia absus exhibit a more Nitric oxide scavenging activity of 52.67% at 750 µg/ml & ascorbate was recorded 67.56% at 750 µg/ml. The IC 50 of the PE concentrates of Cassia absus & ascorbic acid were recorded 822µg/ml &130µg/ml correspondingly.
Nitric oxide scavenging activity of EA concentrates of Cassia absus appeared in Table 5. The EA concentrates of Cassia absus exhibit a more Nitric oxide scavenging activity of 59.84% at 750 µg/ml & ascorbic acid was recorded 67.56% at 750 µg/ml. The

Phosphomolybdic acid method
The total antioxidant activity of PE concentrates of Cassia absus appeared in Table 7. The PE concentrates of Cassia absus exhibit a more total antioxidant activity of 39.78% at 300 µg/ml & ascorbic acid was recorded 98.12% at 300 µg/ml. The IC 50 of the PE concentrates of Cassia absus & ascorbic acid were recorded 740µg/ml &57µg/ml correspondingly.
The total antioxidant activity of the EA concentrates of Cassia absus appeared in Table 8. The EA concentrates of Cassia absus exhibit a more total antioxidant activity of 42.43% at 300 µg/ml & ascorbic acid was recorded 98.12% at 300 µg/ml. The IC 50 of the EA concentrates of Cassia absus & ascorbic acid were recorded 445µg/ml &57µg/ml correspondingly.
The total antioxidant activity of methanol concentrates of Cassia absus appeared in Table 9. The methanol concentrates of Cassia absus exhibit a more total antioxidant activity of 63.18% at 300 µg/ml & ascorbic acid was recorded 98.12% at 300 µg/ml. The IC 50 of the methanol concentrates of Cassia absus & ascorbic acid were recorded 205µg/ml &57µg/ml correspondingly.
IC 50 values & total antioxidant potential revealed that methanol concentrates of Cassia absusis a better activity in scavenging total antioxidant potential when compared ethyl acetate & PE extracts

CONCLUSIONS
The current trends, antioxidative activity of the herbs having more interest due to their possible use as natural additives to substitute synthetic ones. Among the three various extracts, the methanolic extract of Cassia absus exhibited higher potency of antioxidant activity. These results indicate that methanol concentrates of Cassia absus might serve as a natural antioxidant, which may be useful in prevent free radical-induced diseases.