Anti-mycobacterial activity of 22 Iranian endemic or rare plant extracts against multi-drug and extensively drug resistant Mycobacterium tuberculosis

Background: Due to side-effects and lost efficacy of common drugs on new resistance strains of Mycobacterium tuberculosis (Mtb), investigation on novel drugs and natural compounds from rich source of endemic plants is required. Thus, in the present study, the anti-mycobacterial effect of 22 Iranian endemic or rare plant extracts on multi-drug resistance (MDR) and extensively-drug resistance (XDR) Mtb isolates was evaluated. Methods: 22 Iranian endemic and rare plant species from 9 families were collected and extracted by methanol. Their inhibitory-effects were then evaluated against Mtb H37Rv strain, seven clinical MDR-TB and two XDR-TB isolates using resazurin microtiter assay (REMA) method. Best of them were then fractionalized by five different polar solvents (Petroleum-Ether, Dichloromethane, Ethyl-Acetate, n-butanol and water). To find anti-mycobacterial fractions, inhibitory effect of isolated fractions were tested on Mtb H37Rv. Results: Out of the 22 plants, 14 plant extracts demonstrated anti-mycobacterial activity with minimum inhibitory concentration (MIC) ranging from 4 to 30µg/mL against Mtb H37Rv. Eight plant extracts also exhibited anti-mycobacterial activity against MDR and XDR clinical strains of Mtb by MICs, 15-60μg/ml. Crinitaria grimmii and Linum album were the best anti-mycobacterial plants. Among fractions of Crinitaria grimmii, dichloromethane and n-butanol and for Linum album, dichloromethane and Ethyl-Acetate fractions displayed more anti-mycobacterial effect comparing to crude extract on Mtb. Conclusion: The present study confirms the potential role of some plants to treat respiratory diseases as our results have demonstrated that these plants exhibit anti-mycobacterial activity in the acceptable range against Mtb. Thus, these plants could be good sources and alternatives of plant metabolites for anti-TB-drug development.

Morphological, Physiological, and Biochemical Impacts of Different Levels of Long-Term Water Deficit Stress on Linum album Ky. ex Boiss. Accessions

Linum album (Ky. ex Boiss.) is an important medicinal plant that produces compounds such as the well-known anticancer lignan podophyllotoxin and fatty acids. Despite its high medicinal value, it has not yet been studied in detail under agricultural conditions. This study was conducted to evaluate the morphological, phenological, and physiological responses of six L. album accessions under different levels of water deficit treatments (100%, 75%, 50%, and 25% available water) in pot conditions. Based on the results, some of the morphological characteristics of the response to water deficit were established. Accessions UTLA7, UTLA9, and UTLA10 showed a higher seed yield and dry weight of the vegetative part. There was a substantial difference in the occurrence of phenological stages in the accessions. The maturation process was accelerated in plants under stress conditions, and accession UTLA9 completed its complete growth cycle faster than the other accessions. The physiological responses of the different accessions did not show the same pattern on the basis of the characteristics studied, and significant differences were observed depending on the trait and accession. Among the most important results of this study was the diversity of responses in different accessions. Based on these results, it is recommended that morphological features (such as seed yield per plant, plant height, number of inflorescences per plant, shoot and root dry weight) be used to select tolerant accessions for the desired product.

Differential Response of Linum Album Ky. ex Boiss. Accessions to Long-term Water Deficit Stress

Linum album is an important medicinal plant contains important lignan compounds such as podophyllotoxin as well as fatty acids. Despite the high medicinal value, it has not been studied in agricultural conditions so far. This study was conducted to evaluate the morphological, phenological, and physiological responses of six L. album accessions under water deficit treatments (100% available water, 75%, 50%, and 25%) in pot conditions. Based on the results the morphological properties of accessions reduced due to water deficit. Accessions of UTLA7 and UTLA9 showed higher seed yield and dry weight of the vegetative part. The occurrence of phenological stages in the accessions showed a significant difference. Maturity was accelerated in plants under stress conditions, and accession of UTLA9 completed its growth earlier than others. Physiological responses of the accessions did not have the same trend based on the measured traits, and significant differences were observed depending on the trait and accession. The most important result of this study was the diversity of responses in different accessions. The results showed that the effect of water stress on the measured traits depends on the level of stress and accession, which suggests that it is possible to select the tolerable accessions for the production of the desired product. Based on the results, plant breeders may be able to use the chlorophyll content as a marker to identify tolerate L. album accessions.