Background: In this study, strictosidine synthase (STR) from Catharanthus roseus that plays an important role in alkaloid biosynthesis was selected. The purpose of this work was to perform in silico analysis and to predict the three-dimensional structure of this protein that is not available. Results: Physicochemical characterization was performed by Expasy's Protparam server. The computed theoretical isoelectric point (pI) found to be less than 7 indicates the acidic nature of this protein. The aliphatic index 73.04 indicates the thermal stability of the protein. Grand average hydropathy (GRAVY) was predicted to be − 285; this lower value of GRAVY shows the possibility of better interaction of this protein with water. Functional analysis of these proteins was performed by SOSUI server which predicted the transmembrane helix. Secondary structure analysis was carried out by SOPMA that revealed that Alpha helix dominated among secondary structure elements followed by random coil, extended strand, and beta turns. The modeling of the three-dimensional structure of the STR was performed by Swiss model. The model was validated using protein structure checking tools PROCHECK and PROVE. Conclusions: This study reveals in silico analysis by Expasy Protparam server, SOPMA, and SOSUI server. Homology modeling of STR was performed by Swiss model.

Medicinal properties of Asparagus racemosus (vernacular name: Shatavari) are attributed to its steroidal saponins called shatavarins. This plant is facing the threat of being endangered due to several developmental, seasonal constrains and malpractices involved in its collection and storage. To support its conservation, a tissue culture protocol is standardized which produces 20 fold higher levels of shatavarin. Here we evaluate the bioactivity and immunomodulatory potential of in vitro produced shatavarins from cell cultures of AR using human peripheral blood lymphocytes. In vitro produced shatavarin stimulated immune cell proliferation and IgG secretion in a dose dependent manner. It stimulated interleukin (IL)-12 production and inhibited production of IL-6. It also had strong modulatory effects on Th1/Th2 cytokine profile, indicating its potential application for immunotherapies where Th1/Th2 balance is envisaged. Our study demonstrating the bioactivity of tissue cultured AR extracts supports further in vivo evaluation of its immunomodulatory efficacy.

Asparagus racemosus is an important monocot medicinal plant that is in great demand for its steroidal saponins called shatavarins. This study was initiated to optimize the conditions for production of shatavarins in cell cultures of A. racemosus in a modified Murashige and Skoog (MS) medium supplemented with six different combinations of growth regulators. Biomass accumulation was correlated with saponin production over a 30-d culture cycle. Biomass and saponin accumulation patterns were dependent on combinations of growth regulators and the pH of the medium. Maximum levels of saponin and biomass accumulation were recorded on day 25 of the culture cycle within a pH range of 3.4 to 5.6. Total saponin produced by the in vitro cultures was 20-fold higher than amounts produced by cultivated plants. Saponin accumulation was not a biomass-associated phenomenon; cultures which showed the highest biomass accumulation were not the highest saponin accumulators. Maximum biomass (28.30±0.29 gl −1 ) and maximum levels of shatavarin IV (11.48±0.61 mg g −1 ) accumulation was found using a medium containing 2.0 mg l −1 2,4-D, 2 gl −1 casein hydrolysate and 0.005% pectinase. The highest levels of sarsapogenin, secreted and intracellular (4.02±0.09 mg g −1 ), accumulated using a medium containing 1.0 mg l −1 NAA, 1.0 mg l −1 2,4-D, 0.5 mg l −1 BAP, 2 gl −1 casein hydrolysate and 0.005% pectinase, after 25 d. Shatavarins were secreted into the medium and can be isolated easily for further purification.

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