Flavonoid-rich leaf extracts of Stevia rebaudiana: free radical scavenging.
Journal name: Ancient Science of Life
Original article title: FREE RADICAL SCAVENGING ACTIVITY OF FLAVONOID CONTAINING LEAF EXTRACTS OF Stevia rebaudiana Bert
The ANSCI is a peer-reviewed, open-access journal focused on Ayurveda and traditional medicines. It publishes original research, reviews, and literary studies linking traditional knowledge with modern science, covering disciplines like botany, ethnomedicine, pharmacology, and clinical research.
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B. Gopalakrishnan, Adesh A. Bawane, Kusum S. Akki, V.I. Hukkeri
Ancient Science of Life:
(A quarterly multi-disciplinary scientific research journal in Ayurveda)
Full text available for: FREE RADICAL SCAVENGING ACTIVITY OF FLAVONOID CONTAINING LEAF EXTRACTS OF Stevia rebaudiana Bert
Year: 2006
Copyright (license): CC BY-NC-SA
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Summary of article contents:
Introduction
The study investigates the free radical scavenging activity of flavonoids extracted from the leaves of Stevia rebaudiana, a shrub indigenous to South America known for its sweet-tasting leaves. The researchers focused on alcoholic, successive butanolic, and alcoholic extracts to assess their antioxidant properties, specifically against free radicals using in vitro methods like the DPPH assay. The presence of flavonoids in the extracts suggested their potential biological activity, prompting an exploration into their efficacy as antioxidants.
Significance of Flavonoids in Antioxidant Activity
The research demonstrated that the successive alcoholic extract of Stevia rebaudiana exhibited a significant capacity to scavenge free radicals, as indicated by the DPPH assay results. The IC50 values, which indicate the concentration needed to achieve 50% neutralization of free radicals, were recorded at 140 µg for the successive alcoholic extract compared to 76 µg for BHT, a standard antioxidant. Further qualitative analysis of the extracts confirmed the presence of various phytoconstituents, including flavonoids, which are recognized for their role in antioxidant mechanisms. The Dot-Blot test on silica layers also reinforced the scavenging activity, underscoring the potential utility of Stevia extracts in mitigating oxidative stress.
Conclusion
The findings of this study suggest that the leaves of Stevia rebaudiana possess notable antioxidant properties, primarily attributed to their flavonoid content. The superior free radical scavenging activity of the successive alcoholic extract positions it as a promising candidate for further investigation into its therapeutic potential. Future research could focus on isolating specific bioactive flavonoids and exploring their efficacy in various biological models to ascertain their full range of health benefits. Overall, Stevia rebaudiana could serve as a valuable source of natural antioxidants, contributing to the development of functional foods and dietary supplements aimed at combating oxidative stress-related diseases.
FAQ section (important questions/answers):
What are the main findings about Stevia rebaudiana extracts?
The extracts showed significant free radical scavenging activity, especially the successive alcoholic extract, which had an IC50 value of 140 µg, indicating strong antioxidant potential compared to BHT at 76 µg.
How were the extracts of Stevia prepared for testing?
The leaves were extracted using 95% ethanol in a Soxhlet apparatus, followed by successive extractions with various solvents including pet ether, butanol, and ethyl acetate, yielding extracts for analysis.
What method was used to assess free radical scavenging activity?
The DPPH assay method was employed, measuring the absorbance decrease at 515 nm to quantify the scavenging potential of the extracts against DPPH radicals.
What phytoconstituents were identified in Stevia extracts?
Qualitative analysis revealed the presence of carbohydrates, flavonoids, steroids, triterpenoids, tannins, glycosides, and proteins, indicating a rich composition of bioactive compounds with potential antioxidant properties.
Glossary definitions and references:
Scientific and Ayurvedic Glossary list for “Flavonoid-rich leaf extracts of Stevia rebaudiana: free radical scavenging.�. This list explains important keywords that occur in this article and links it to the glossary for a better understanding of that concept in the context of Ayurveda and other topics.
1) Activity:
Activity in this context refers to the effectiveness of the extracts from Stevia rebaudiana in scavenging free radicals. It is a crucial aspect of evaluating the antioxidant potential of the extracts, indicating their ability to reduce oxidative stress, which can contribute to various health benefits and reduce the risk of diseases caused by free radicals.
2) Flavonoid:
Flavonoids are natural compounds found in plants, especially in the leaves of Stevia rebaudiana, which exhibit antioxidant properties. They play an important role in the study because their presence in the extract is linked to the scavenging activity against free radicals, thereby showcasing the health benefits derived from consuming flavonoid-rich substances.
3) Water:
Water serves as a solvent in the extraction processes discussed in the study. It is important in the context of preparing extracts that may contain various phytoconstituents, including flavonoids. Moreover, water's role in the solvent system used during the Dot-Blot test highlights its significance in analyzing compound interactions and characteristics.
4) Science (Scientific):
Science encompasses the systematic study of the natural world, including the examination of plant extracts for their chemical constituents and biological activities. This research falls under the fields of pharmacognosy and botany, focusing on the extraction, identification, and assessment of the antioxidant properties of Stevia rebaudiana, thus contributing to scientific knowledge about natural antioxidants.
5) Transformation (Transform, Transforming):
Transformation refers to the process whereby the DPPH radical, a stable free radical utilized in antioxidant assays, is reduced to its non-radical form, indicating scavenging activity. This transformation is pivotal as it represents the efficacy of the extracts in neutralizing free radicals, a core aspect of evaluating their potential health benefits.
6) Discussion:
Discussion in a scientific paper involves interpreting the results obtained from experiments, analyzing their implications, and comparing findings with existing literature. In this study, the discussion highlights the significance of the free radical scavenging capacity of Stevia extracts and paves the way for future research into their bioactive components and health applications.
7) Botany:
Botany, the study of plants, is integral to understanding the characteristics and properties of Stevia rebaudiana. This research involves the identification and classification of plant constituents that contribute to its antioxidant activity, thereby merging botanical knowledge with pharmacological applications to explore the therapeutic potential of plant-based substances.
Other Science Concepts:
Discover the significance of concepts within the article: �Flavonoid-rich leaf extracts of Stevia rebaudiana: free radical scavenging.�. Further sources in the context of Science might help you critically compare this page with similair documents:
Stevia rebaudiana, Antioxidant activity, Free radical scavenging activity, Butanolic extract, DPPH assay method, Successive extraction, Qualitative chemical analysis, Radical scavenging capacity.