Antimicrobial Activity of Artemisinin and Precursor Derived from In Vitro Plantlets of Artemisia annua L.

Artemisia annua L., a medicinal herb, produces secondary metabolites with antimicrobial property. InMalaysia due to the tropical hot climate, A. annua could not be planted for production of artemisinin, themain bioactive compound. In this study, the leaves of three in vitro A. annua L. clones were, extracted and two bioactive compounds, artemisinin and a precursor, were isolated by thin layer chromatography. These compounds were found to be effective in inhibiting the growth of Gram-positive and Gram-negative bacteria but not Candida albicans.Their antimicrobial activity was similar to that of antibactericidal antibiotic streptomycin. They were found to inhibit the growth of the tested microbes at the minimum inhibition concentration of 0.09mg/mL, and toxicity test using brine shrimp showed that even the low concentration of 0.09mg/mL was very lethal towards the brine shrimps with 100% mortality rate. This study hence indicated that in vitro cultured plantlets of A. annua can be used as the alternative method for production of artemisinin and its precursor with antimicrobial activities

Effect of Basal Medium on In Vitro Leaf Morphology, Growth and Artemisinin Production of Artemisia annua L.

Artemisia annua L. was classified as one of the important medicinal plants due to its potential in the treatment of malaria. However, the propagation of this plant was limited by environmental and geographical factors. Therefore, in vitro culture technique was an alternative to overcome these limitations. Five different basal media were examined for their effect on the growth and artemisinin content of in vitro plantlets of A. annua. They were found to give different effect on the growth in term of height, fresh biomass and rooting ability of the plantlets. Glandular and non-glandular filamentous trichomes were observed on the adaxial and abaxial surface of A. annua leaf. The five basal media was found to affect the distribution and the number of trichomes and stomata formed on the leaf surfaces. LV medium induced more trichomes formation of both types on both leaf surfaces. Highest number of stomata was found on the leaf surface of the plantlets cultured in MS medium. While B5 medium resulted in non formation of stomata on the abaxial leaf surface of all the studied clones. Artemisinin production was found to greatly affect by the choice of basal medium used for cultivation. Keywords: Artemisia annua, artemisinin, basal medium, growth pattern, stomata, trichome

Somatic Embryogenesis: An Alternative for Propagating Selected Highland Clone of Artemisia annua L. of Vietnam Origin

Artemisinin, currently used in malaria treatment therapy, is produced  in Artemisia annua L. Conventionally, A. annua is propagated via seeds which result in variation in plant quality and production of artemisinin content. Various in vitro culture techniques have been used for production of A. annua plantlets. In the present study, somatic embryogenesis protocol was successfully established for A. annua of Highland clone of Vietnam origin. Somatic embryos of A. annua could be induced from the leaf explants on Murashige and Skoog (MS) medium supplemented with 0.5 mgL-1 BAP (6-Benzylaminopurine) and 0.5 mgL-1 NAA (1-napthaleneacetic acid), 3% sucrose and 0.5 mgL-1 casein hydrolysate (CH). Proliferation of embryogenic calli was enhanced in MS medium added with 0.1- 2.0 mgL-1 2,4-dichlorophenoxy-acetic acid (2, 4-D) and 0.5 mgL-1 casein hydrolysate (CH). The somatic embryos after culturing onto MS medium supplemented with 0.5 mgL-1 BAP developed into shoots. Plantlets were then generated after rooting the micro-shoots in MS medium supplemented with 1.0 mgL-1 IBA. The somatic embryos derived plantlets produced flowers and bore fruits and seeds two months earlier in tropical climates as compared to cool environment. Keywords: artemisinin, somatic embryos, embryogenic callus, leaf explant