[In vitro evaluation of methanol extract of Agrimonia eupatoria on PBMC and 12 pathogenic bacteria]

Background: Today the use of medicinal plants to improve the immune system function and against pathogenic bacteria has been considered

Objective: In this study, the effect of methanol extract of the aerial parts of Agrimonia eupatoria on peripheral blood mononuclear cells [PBMC] and 12 pathogenic bacteria were investigated

Methods: The methanol extract of branches, stems, seeds and leaves of Agrimonia eupatoria were prepared and the effect of different concentrations of 50, 100, 500, 1000, 1500, 2000 and 2500 micro g/ml of the extract on proliferation of PBMC was evaluated by MTT assay. Also the effect of concentrations of 1, 2, 4, 5, 7 and 10 mg/ml of the extract was tested on 12 pathogenic bacteria by disc method and on nutrient agar media

Results: The methanol extract of the branch, stem and seed of Agrimonia eupatoria showed the most stimulatory effects on immune system and induced the proliferation of PBMCs up to 8 times. Methanol extract of Agrimonia eupatoria showed antibacterial effects against gram-positive bacteria and the most antibacterial effect was on Bacillus subtilis at a concentration of 4 mg/ml and Staphylococcus aureus at concentration of 7 mg/ml

Conclusion: The Agrimonia eupatoria methanol extract showed stimulatory effects on the immune system and also antibacterial properties against certain gram-positive pathogenic bacteria. These finding indicate that Agrimonia eupatoria can be considered to use for immunodeficiency patients and moreover to control some bacterial infections

[Improvement of artemisinin production in hairy roots culture of Artemisia annua L. by Staphylococcus aureus]

Artemisinin is an important plant secondary metabolite with anti-malaria, antiviral and anti-cancer properties. In recent years many efforts have been made to improve artemisinin production through plant tissue culture [such as hairy roots]. In this study, the effects of Staphylococcus aureus on artemisinin production in hairy roots of Artemisia aureus were investigated. Agrobacterium rhizogenes; strains A7 and Ar318 were used for the root induction. Two explants types were prepared, the first was leaf explants cut from both side [explant 1] and the second was, stems which cut from node [explant 2]. The bacterial suspensions [A7 and Ar318] were inoculated at the wounding site of explants I and node explants 2. Transgenic nature of hairy roots was confirmed by amplification of rolB gene in polymerase chain reaction [PCR]. Gas chromatography [GC] was conducted to determine artemisinin production. About 5 to 10 days after inoculation by A7, hairy roots were appeared at the wounding sites of explants 2. Strain Ar318 could not induce any hairy roots. Also, after treatment with Agrobacterium suspensions, hairy roots were not induced in the explants I and explants were necrotic. The artemisinin content in the hairy roots treated with S. aureus suspension was 0.063, 0.133, 0.046 and 0.043 mg/g DW, respectively. Results show that various factors such as type of explants and Agrobacterium strains were effective in hairy roots induction. It seems that Staphylococcus aureus is stimulating the production of artemisinin in hairy roots of Artemisia annua

[Hairy root induction in Burdock [arctium lappa L.]]

Arctium lappa is a medicinal plant, which natively grows in Iran. Arctiin and arctigenin are two of the most important secondary metabolites produced in this plant and used as anticancer reagents. Application of biotechnological methods for increasing the production of these metabolites is very essential. Recently, induction of hairy roots in plants to improve the production of desirable secondary metabolites has been considered. In this study, hairy roots were induced in Arctium lappa using Agrobacterium rhizogenes, strain AR15834. The leaf explants and seedlings of Burdock were used for the hairy roots induction. The leaf explants were turned brown and died when cultured in vitro. To improve the viability of these explants, different antioxidants including ascorbic acid [ASC], citric acid [CIT], polyvinylpyrrolidone [PVP] and L-cysteine were added to the MS medium, in different concentrations either alone or in combination with each other. Polymerase Chain Reaction [PCR] for rolB gene confirmed the morphological identification of the transformed hairy roots. Although the best antioxidant reagent was PVP 0.5% [w/v], it did not stop tissues browning of the leaf explants when they were co-cultured with A. rhizogenes for the hairy roots induction. When the two or three weeks old seedling were used for the hairy roots induction, the roots were observed 2 weeks after the bacterial infection with 5% frequency. In this study, A. rhizogenes induced hairy roots in Burdock. To the best of our knowledge, this is a first report on the hairy roots induction in Arctium lappa