Comparative Evaluation of Antioxidant Activity of Sariva Sources (Hemidesmus indicus & Decalepis hamiltonii) - An In Vitro Study

Introduction

In recent times, due to modernized and sedentary life style, the society is suffering from many health hazards. One of the main causative factors for these pathological changes are free radicals. Free radicals are lacking by one electron; hence they strive for balance and attack neighboring molecules, making them unstable as well. This process continues to damage DNA, attacks enzymes & proteins, disrupts normal cell activities, thus leading to various pathological conditions. To combat that, the focus is on antioxidants, which can scavenge and prevent the chain of free radicals. The search for antioxidants that are cost effective and abundantly available is the need of the hour.

In Ayurveda, reference about drugs having Rasayana karma, Rakta prasadana karma can be noted and one such drug is Sariva. ¹ Sariva is attributed with Varnya, Rakta prasadana and Rasayana karma. ^2,3 These above mentioned karma can be understood by the concept of free radicals and antioxidants.⁴ Hence the drug Sariva was screened for the antioxidant activity by in vitro method.

In the classics of Ayurveda, the drug Sariva is said to be of two varieties - Shweta & Krishna and both are said to be Rasayana, Rakta Prasadana. The sources of Shweta & Krishna Sariva are, Hemidesmus indicus, Ichnocarpus frutiscens, & Cryptolepis buchnani. Another source that is sold in the name of Sariva is Decalepis hamiltonii, and it almost replaced the genuine drug. It is used by most of the pharma companies for the preparation of medicines. Hence an attempt was made to compare the antioxidant activity of Hemidesmus indicus, a genuine source of Sariva & Decalepis hamiltni which almost replaced the genuine drug in the market by in vitro method.

Materials and Methods

Drug collection

The Sariva sources were collected from their natural sources, authenticated by Department of PG studies in Dravyaguna, BLDEA’s AVS Ayurveda Mahavidyalaya, Vijayapur.

Sample preparation

The roots of both the sources collected were dried, powdered and methanolic and aqueous extracts were prepared by Soxhlet method. The extracts were subjected to in vitro studies.

In vitro study

DPPH assay

Procedure: This assay was carried out based on the method of Costa et al. (2012) and Plank et al. (2012) with slight modification.

0.1 mM of methanolic DPPH stock solution was prepared freshly using 10 mg DPPH dissolved in 125 mL methanol in a 250 mL volumetric flask. A 0.4 mL diluted sample or standard solution was added to the test tube containing 5.6 mL methanolic DPPH. Test tubes were sealed with parafilm, incubated in water bath (Memmert, Germany) at 37^o C for 30 min. The absorbance was measured against methanol (Blank) at 517 mm UV-Visual spectrophotometer. Trolox calibration solutions of 50- 500 um concentration were used to generate the standard curve. The results were expressed as umol/ 100 mL [Costa et al. 2012].

Total Phenolic Assay

Procedure: The phenolic content of juices was determined spectrophotometrically according to Folin– Ciocalteu method with slight modification by Mahadavi et al. (2010) and Singleton & Rossi (1965). About 0.4 mL of sample or standard solution was added to 10 mL volumetric flask, containing 3.6 mL of distilled water. Folin- Ciocalteu reagent (0.4) was added to the mixture. About 4 mL of 7% sodium carbonate was also added after five minutes. The solution was made up to 10 mL with distilled water, mixed thoroughly and allowed to stand at room temperature for 90 min. The absorbance was measured at 765 nm using UV- Visual spectrophotometer against distilled water as blank. Calibration curve was plotted using Gallic acid standard solution of 0-250 mg/L. The result was expressed as Gallic acid equivalent (mg GAE/ 100 mL).⁵

Results

DPPH assay of Hemidesmus indicus

Total Phenolic assay of Hemidesmus indicus

Total Phenolic assay of Decalepis hamiltonii

Discussion

Phytoconstituents present in the plant extract contribute significantly towards the biological activities of medicinal plants such as antioxidant, immunomodulating properties (Ahamed et al. 2017). Polyphenol flavonoids present in medicinal plants as glycosides contain several phenolic hydroxyl groups. Many flavonoids are found to be strong antioxidants effectively scavenging the reactive oxygen species.

In this research work, DPPH and total phenolic content tests were selected as DPPH is a frequently used standard method. Total Phenolic Content is the test undertaken for the quantification of phenols present in the sample.

The present study results suggest that the methanolic extract of both the samples show better antioxidant activity compared to aqueous extract which could be because the metabolites in the plants contributing to the antioxidant property such as flavonoids, phenols are more soluble in alcohol than water.

DPPH assay

In the DPPH analysis, D. hamiltonii showed better results which almost matched with the standard Vitamin C, whereas H. indicus readings were lower compared to D. hamiltonii. The results of free radical scavenging activity showed that both the samples reduced DPPH free radicals to non-radical DPPH by compounds having hydroxyl groups. The phenolics, flavonoids, present in both the samples can donate hydrogen to terminate the odd electrons of DPPH radical. The comparative analysis of both the samples showed that D. hamiltonii exhibited more radical scavenging activity than H. indicus probably because the previous one has more secondary metabolites like flavonoids, diterpinoids.

Total phenolic content

Phenolic compounds act as antioxidants due to their redox properties which allows them to act as hydrogen donors, reducing agents and singlet oxygen quenches (Kasote et al. 2015). Total phenolic content could be used as basis for their most potent antioxidant properties and their free radical scavenging ability is eased by their hydroxyl group (Baba et al. 2015). In this study, H. indicus showed highest phenolic content. Based on this, it can be said that H. indicus, an original source of Sariva explained in Ayurvedic classics is a good source of antioxidants.

Conclusion

In the present study, H. indicus and D. hamiltonii were selected for the comparison of the antioxidant properties because the original source of Sariva is H. indicus according to Ayurvedic Pharmacopea of India and D. hailtonii is available in the name of Sariva in the market, almost replacing the original drug. Based on this study, it can be concluded that D. hamiltonii being different species than original Sariva can be considered as a potent substitute for the original drug.

Conflicts of Interest

Nil