Mohammad Norani; Mohammadtaghi Ebadi; Mehdi Ayyari Noushabadi
Abstract
Introduction: Coltsfoot (Tussilago farfara L.) from Asteraceae family is a perennial plant. T. farfara is native and widespread from Europe to Western and Northern Asia and North Africa. Coltsfoot distributed in wet mountainous regions of Iran, such as Azerbaijan, Tehran and Northern provinces. Its flowers ...
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Introduction: Coltsfoot (Tussilago farfara L.) from Asteraceae family is a perennial plant. T. farfara is native and widespread from Europe to Western and Northern Asia and North Africa. Coltsfoot distributed in wet mountainous regions of Iran, such as Azerbaijan, Tehran and Northern provinces. Its flowers and leaves have been used traditionally for the treatment of cough, bronchitis and phlegm disorders. T. farfara leaves and flowers have expectorant activity and are used for chronic dry cough and various pulmonary diseases. The extracts of T. farfara were shown to exhibit various activities, such as antioxidant and antimicrobial activity. Biologically active agents of T. farfara have been studied due to their antimicrobial and antioxidant characteristics.
Materials and Methods: For morphological study, the rhizomes of seven Iranian coltsfoot populations were collected in August 2016 from different regions of Iran including Pol-e zangholeh, Damavand, Firoozkooh, Nur, Deylaman, Kaleybar and Namin. The collected samples were planted in the same condition during 2016-2017 in research field of Tarbiat Modares University in Tehran (51º10ʹ23ʺ N, 35º44ʹ17ʺ E), with a randomized complete block design experiment and three replications. The average annual rainfall and temperature of cultivating place is about 220 mm and 16.4 ºC. In order to study the morphological characteristics between different samples, traits such as the number of flowers per plant, stem height, flower length, flower diameter, flower dry weight, root length, root dry weight, leaf area and leaf dry weight had been measured. Morphological traits were measured under the same conditions and for this research, were used ruler, caliper and balance. The leaves and flowers were prepared for phytochemical studies. DPPH method has been used to evaluate the antioxidant activity, and the IC50 was used to compare the antioxidant properties. The absorbance of the samples was measured at 517 nm with ELISA reader. The radical scavenging capacity (RSC) was calculated by the following formula: % In=[(Ab-As)/Ab]×100, where In is DPPH inhibition, Ab is the absorbance of the blank, As is the absorbance of samples including extracts and BHT as a positive control. The phenolic contents of different extracts were determined by Folin-Ciocalteu method and the aluminum chloride method was used to measure total flavonoid.
Results and Discussion: Analysis of variance showed that there is a significant difference between all evaluated traits in studied populations (p ≤0.01). Pol-e zangholeh population of T. farfara, has shown the best performance for all morphological traits. The results of the flowers per plant showed that the Pol-e zangholeh population was the highest and the Deylaman population had the lowest number of flowers. The maximum length of the stem was related to the Pol-e zangholeh population while the population of Namin had the smallest amount. Comparison of flower diameter showed that the Pol-e zangholeh population had the largest diameter and Nur population of all the smaller. The results of the flower length showed that the maximum flower length was related to the Pol-e zangholeh population and Deylaman population had the smallest amount of flower length. Comparison of mean of flower dry weight showed that the Pol-e zangholeh population of T. farfara had the highest value while the population of Nur had the smallest amount. Pol-e zangholeh population of T. farfara, considered as superior populations and its flowering time were earlier than the others. It was found that there is a significant difference (p ≤0.01) between different populations. This variation may be due to Population differences of People, either due to differences in environmental conditions or sometimes due to the interaction of the population and the environment. Our results also indicate the presence of comparable genetic potentials of T. farfara in these population for any further cultivar development. Analysis variance showed that there was significant difference between populations for total phenol, flavonoid and antioxidant activity (p ≤0.01) and the Nur population had the highest total phenolic content and highest antioxidant activity. Comparison of antioxidant activity of different extracts from leaves and flowers of T. farfara showed that the most antioxidant activity was related to leaf extract of Nur population with IC50 271 µg/ml closer to BHT (33 µg/ml) as a synthetic and industrial antioxidant. The least amount of this activity was related to Kaleybar leaf extract with IC50 888 µg/ml. Nur population showed the highest total phenol content with 242 mg GAE/g dried weight. Damavand population showed the highest total flavonoid content with 40 mg QE/g DW extract.
Conclusion: Our results indicate the presence of comparable potentials of T. farfara in these populations for any further cultivar development. Study of antioxidant activity in different habitats shows that Nur habitat is a suitable place for the cultivation of T. farfara to increase the amount of phenolic compounds and antioxidant activity.