Saponins are secondary metabolites that are found in many plants and some animals. These compounds are high molecular weight glycosides, consisting of a sugar moiety linked to a triterpene or steroid aglycone. Many saponins have detergency properties and give stable foam in water. The genus Silene L. with more than 700 species is one of the largest genera of the family Caryophyllaceae mainly distributed in northern hemisphere. Saponins are one of the important secondary metabolites in the members of the genus. Quantitative and qualitative study of the saponins in the aerial parts and roots of three Silene species, namely S. ginodioica Ghaz. subsp. Penducularis (Fenzl ex Boiss.) Melzh., S. spergulifolia (Willd.) M. Bieb. and S. swertiifolia Boiss. were carried out by spectrophotometry and TLC methods. In this study, 5 fractions were obtained from each plant part and in both parts of the three species, fraction 1 contains the highest amounts of saponins. On the other hands, root extracts have high amounts of saponins. In addition, thin layer chromatography (TLC) of the extracts revealed some saponins spots with different R_f.

Nerve growth factor (NGF) is a neurotrophic factor that is functional in the survival, maintenance and differentiation of nervous system cells. This protein has three subunits, of which the beta subunit has the main activity. Its structure consists of a cysteine knot motif made up of beta strands linked by disulfide bonds. It can be used as a therapeutic agent in the treatment of many diseases. As NGF extracted from natural sources is unsuitable for therapeutic goals, many studies have attempted to produce recombinant β-NGF. In this study, Trigger Factor (TF) chaperone was expressed simultaneously with β-NGF in E. coli in order to obtain increased yield of soluble recombinant human β-NGF.  For this purpose, pET39b (+)::β-NGF and chaperone plasmid pTf16 were transferred to E.coli (DE3 strain). After the induction of each promoter, the total proteins and periplasmic proteins were extracted. To confirm the effects of TF on total protein and soluble β-NGF expression level, Bradford and Dot blot techniques and ImageJ software were used. Then, β-NGF was purified using affinity chromatography column (Ni⁺²-NTA). Also, the PC12 cells were treated with the protein for one week in order to study the function of purified NGF. Our data indicated that co-expression of TF could increase the soluble and periplasmic production of β-NGF but not total proteins. Also, the treatment of PC12 cell line with purified β-NGF, co-expressed with TF chaperone, showed differentiation of these cells to nerve cells. This indicated that the purified NGF is fully functional. Our data suggest that the co-expression of cytoplasmic chaperone (TF) with recombinant nerve growth factor might be an efficient approach to produce a proper quantity of soluble and active rhNGF.