Biosynthetical Capacity of Kaempferol From in Vitro Produced Argel (Solenostemma Argel (Del.) Hayne) Callus

Abstract

Solenostemma argel (Del.) Hayne (family Asclepiadaceae) is an Egyptian natural perennial shrub. The study attempted to establish callus from S. argel and to investigate its biosynthetic potentiality to produce the flavonoid kaempferol, which has a wide range of pharmacological activities. Seeds and aerial parts were collected from naturally grown plants at Saint Catherine, Sinai. Callus from different explants of in vitro germinated seedlings (stem, leaf and root) was successfully initiated on Murashige and Skoog (MS) medium supplemented with each of 2,4-dichlorophenoxyacetic acid (2,4-D) and βnaphthalene acetic acid (NAA), separately, at concentrations of 1.0, 2.0 and 3.0 mg/L, in addition to 0.5 mg/L kinetin (KIN). However, the fresh weights of leaf-derived callus were the highest. Casein hydrolysate (CH) and yeast extract (YE), as elicitors, at concentrations of 0.5, 1.0 and 2.0 g/L, were examined for elevating the in vitro production of kaempferol in callus cultures. The total methanol extracts of the aerial parts of wild plants, four-week-old in vitro germinated seedlings' explants and their derived callus were analyzed qualitatively and quantitatively for kaempferol, using HPLC. A significant difference in the content of kaempferol was observed. Callus produced from tested explants showed a capacity for production and accumulation of kaempferol. The highest concentration of kaempferol was in callus obtained from seedlings' stem explants on MS medium containing 1.0 mg/L 2,4-D and 0.5 mg/L KIN, in addition to 2.0 mg/L YE. In conclusion, S. argel callus cultures showed a capacity for synthesizing kaempferol and could be an alternative renewable natural source for its large-scale production.