Document Type : original paper
Authors
1
Department of Horticultural Sciences, Faculty of Agriculture & Natural Resources, University of Hormozgan, Bandar Abbas, Iran
2
Department of Horticultural Sciences, Faculty of Agriculture & Natural Resources, University of Hormozgan, Bandarabbas, Iran.
3
Department of Natural Resources Engineering, Faculty of Agriculture & Natural Resources, University of Hormozgan, Bandar Abbas, Iran
10.22069/jopp.2025.24006.3279
Abstract
Background and objectives: Teucrium polium L., a perennial medicinal plant from the Lamiaceae family, is renowned in traditional medicine for its hypoglycemic properties. Its flowering tops contain phenolic and flavonoid compounds, which are associated with tonic, analgesic, and antioxidant effects. Given the influence of environmental factors on phytochemical composition, this study aimed to evaluate the antioxidant activity, total phenolic content (TPC), and total flavonoid content (TFC) of 18 ecotypes from southern Iran. The objective was to identify superior ecotypes with an optimal phytochemical profile for pharmaceutical applications and to establish a basis for their conservation and commercial cultivation.
Methodology: Eighteen T. polium ecotypes were collected at full flowering stage from various habitats in southern Iran, encompassing the provinces of Hormozgan, Kerman, Bushehr, and Kohgiluyeh and Boyer-Ahmad. The flowering branches were dried in shade at room temperature, powdered, and subjected to methanolic extraction using maceration. TPC was determined using the Folin-Ciocalteu reagent, with absorbance measured at 750 nm and quantified against a gallic acid standard curve. TFC was assessed via the aluminum chloride colorimetric method, measuring absorbance at 415 nm against a quercetin standard. Antioxidant capacity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, measuring absorbance at 517 nm. All measurements were performed in triplicate, and data were analyzed using one-way ANOVA and Duncan's multiple range test (p < 0.05).
Results: Habitat significantly influenced the phytochemical properties of T. polium (p < 0.01). Among the 18 ecotypes, the Siyahoo ecotype (Hormozgan) exhibited the highest TPC (86.66 mg GAE/g DW), while the Kondar ecotype (Kerman) showed the highest TFC (56.45 mg QE/g DW). The Narrab ecotype (Kerman) demonstrated the highest IC50 value (85.02 µg/ml), indicating its weaker antioxidant activity. Correlation analysis revealed a significant positive relationship (R² = 0.82) between TPC and antioxidant power (inverse of IC50), confirming the contribution of phenolics to the plant's antioxidant activity. Ecotypes from Kerman and Hormozgan provinces consistently outperformed those from Bushehr and Kohgiluyeh and Boyer-Ahmad. Siyahoo exhibited a 25% higher phenolic content than the average of other ecotypes, whereas Kondor was superior in flavonoids. Significant statistical differences (p < 0.05) among ecotypes highlighted the impact of environmental factors, such as altitude and rainfall, on phytochemical diversity.
Conclusion: The findings demonstrate that the ecological conditions of high-altitude regions, characterized by greater solar radiation, temperature fluctuations, and lower precipitation, significantly enhance the phenolic and flavonoid compounds and antioxidant capacity of T. polium. This underscores the necessity of concurrently considering environmental factors like altitude, temperature, and rainfall when selecting elite germplasms for pharmaceutical and industrial purposes. The introduction of high-yielding ecotypes (e.g., Kondar, Siyahoo, and Esfandagheh) can pave the way for sustainable cultivation, conservation of natural resources, and improved quality of plant-based pharmaceutical products.
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