Antioxidant properties of various parts Cissus quadrangularis L. in different solvents

An important medicinal plant Cissus quadrangularis , belonging to the family Vitaceae was used in the present study to estimate antioxidant properties of different extract (root, stem, leaves and tendrils). Plant materials were collected from the village Ponnanthittu, Cuddalore Dist, The antioxidant properties of the petroleum ether, chloroform, ethyl acetate, acetone and methanol extracts of Cissus quadrangularis were screened and results showed considerable antioxidants in all the extracts.


INTRODUCTION
Medicinal plants are the backbone of the traditional medicines [1]. The past 2500 years, there have been very strong traditional systems of medicines born and practiced more in the eastern continent. Approximately 80% of population in the developing countries still rely on these systems of medicines for their primary health care needs [2]. Moreover, herbal medicines are considered to be less toxic and free from side effects than synthetic ones. The chemical compounds found in plants are natural products that have pharmacological and biological activity and hence, they are generally used in drug discovery and drug design [3]. Medicinal plants are rich source of compounds or secondary metabolites like tannins, terpenoids, alkaloids, flavonoids, etc. [4,5].
Cissus quadrangularis is an important medicinal plant with traditional and modern medicinal uses [6]. Previous studies are about antioxidant potentials from stem of plants and with antimicrobial actions from this plant [7] and antioxidants from stem portions [8]. In the present study, we aimed to estimate antioxidant properties of different extract (root, stem, leaves and tendrils) from medicinal plant Cissus quadrangularis.

DPPH Free Radical Scavenging Activity
The DPPH scavenging activity of different extracts of C. quadrangularis root, stem, leaves and tendrils were measured according to the procedure described by Hatano et al. [9].

Superoxide Anion Radical Scavenging Activity Assay
The Superoxide anion radical scavenging was measured by the method of Liu et al. [11].

Hydrogen Peroxide (H 2 O 2 ) Scavenging Assay
Hydrogen peroxide scavenging activity of the extract was measured by standard method [12].

Hydroxyl Radical Scavenging Assay
The scavenging activity for hydroxyl radicals was measured with fenton reaction by the standard method [13].

Ferric Reducing Antioxidant Power (FRAP)
The FRAP assay was used to estimate the reducing capacity of plant extracts, according to the method of Benzie and Strain [14].

Determination of Total Antioxidant Activity
The antioxidant activity of the extracts was evaluated by the phosphomolybdenum method according to the procedure of Prieto et al. [15].

RESULT AND DISCUSSION
The antioxidant properties of the petroleum ether, chloroform, ethyl acetate, acetone and methanol extracts of Cissus quadrangularis were screened and results showed considerable antioxidants in all the extracts. The ethanolic extracts of the leaves of Carica papaya, Psidium guajava and Vernonia amygdalina, stem bark of Mangifera indica were screened for the their free radical scavenging activity [16]. The antioxidant screening of ethanolic extracts of Viola serpens and Morus nigra showed the presence of enzymatic antioxidant such as catalase, peroxidase and ascorbate oxidase and non-enzymatic antioxidant such as ascorbic acid [17].
The antioxidant activity by DPPH method indicated that ethanolic extract of Phragmytes vallatoria possessed considerable antioxidant activity. The highest radical scavenging activity was IC50=73 µG/mL. Seven compounds were identified in GC-MS analysis [18].

Superoxide Radical Scavenging Activity
The results of superoxide radical scavenging activity of petroleum ether, chloroform, ethyl acetate, chloroform and methanolic extracts root, stem, leaves and tendrils of C. quadrangularis and standard are shown in Figure 1. The inhibition of superoxide anion radical scavenging activity generation is lower than that of ascorbic acid (standard). The inhibition of SOD at the concentrations (20, 40, 60, 80 and 100 µg/mL) recorded.

Hydrogen Peroxide Scavenging Activity
The results of hydrogen peroxide scavenging activity in various extracts of C. quadrangularis are shown in Figure 3. A significant activities was found among the samples of C. quadrangularis in different concentrations of 20, 40, 60, 80 and 100 µg/mL. The highest H 2 O 2 scavenging potential was recorded with methanol extracts of all the samples, followed by ethyl acetate, acetone, chloroform and petroleum ether. Among the various parts of plant, the highest antioxidant potential was observed in stem, followed by leaves, root and tendrils. The hydrogen peroxide scavenging activity of methanolic extracts of root, stem, leaves, tendrils and control were 20.23 ± 0.01, 31.15 ± 0.01, 24.61 ± 0.01, 19.28 ± 0.01 and 38.53 ± 0.05 µg/mL respectively at 100 mg/ml concentration. The IC 50 values of methanolic extracts of root, stem, leaves, tendrils and control were 430, 289, 329 and 489 µg/mL respectively when compared to the ascorbic acid (254 µg/mL).

Ferric Reducing Antioxidant Powder Assay (FRAP)
The FRAP assay results of different extracts of C. quadrangularis are presented in Figure 4. The inhibition of FRAP generation was lower than that of ascorbic acid. The inhibition of FRAP at the concentration of 20, 40, 60, 80 and 100 µg/mL was recorded. On the other hand, at the same concentration of ascorbic acid, the highest antioxidant activity was observed in stem of C. quadrangularis and then followed by leaves, root and tendrils. Among the extracts, methanol extracts exhibited the potential FRAP values. The FRAP values of methanolic extracts of root, stem, leaves, tendril and ascorbic acid were 12.45 ± 0.04, 17.52 ± 0.02, 14.23 ± 0.02, 9.71 ± 0.02 and 20.92 ± 0.03 µg/mL respectively at 100 mg/ml concentration. The IC 50 values of the same extracts were 690, 589, 683 and 725 µg/mL respectively compared with standard value (503 µg/mL).

Total Antioxidant Activity
The results of total antioxidant activity of different extracts of C. quadrangularis are shown in Figure 6. A significant result was recorded in various concentrations of 20, 40, 60, 80 and 100 µg/mL. The highest total antioxidant activity was observed in stem extracts and then followed by leaves, root and tendrils. Among the solvents, the methanol extracts produced potential total antioxidant properties when compared to other solvents. The total antioxidant values of methanol extracts of C. quadrangularis were 48.12 ± 0.02 µg/mL (root), 77.87 ± 0.03 µg/mL (stem), 57.06 ± 0.02 µg/mL (leaves), 26.56 ± 0.03 µg/mL (tendrils) and 89.96 ± 0.02 µg/mL (standard value) at 100 mg/mL concentration. The methanol extracts exhibited IC 50 values were 286 µg/mL (root), 212 µg/mL (stem), 245 µg/mL