effect of mannitol, sucrose, and hydrolyzed casein on hypericin content, gland number, and red pigment synthesis in the in vitro culture of hypericum perforatum cv. helos

Objective: this study aimed to establish a protocol for enhancing the quantity of hypericin, glands, and red pigments in hypericum perforatum cv. helos.methods: the effects of hydrolyzed casein (0 and 500 mg/l), mannitol (0, 5, and 10 g/l), and sucrose (20 and 30 g/l) on leaf explants derived from the in vitro plantlets were evaluated. the factors were arranged in a factorial experiment using a completely randomized design with three replications and five samples per experimental unit.results: the concentrations of hydrolyzed casein, mannitol, and sucrose markedly influenced the proportions of callus formation and the shoots displaying red pigments. the highest proportion of red pigment-bearing calli was observed in the media containing either the control or 500 mg/l hydrolyzed casein with 20 g/l sucrose, without mannitol. glands were observed on all shoots that underwent development. the maximum gland number and the highest percentage of shoots with glands were recorded for the explants cultured on media containing 30 g/l sucrose in combination with 5 or 10 g/l mannitol, and similarly for the medium with 20 g/l sucrose and 5 g/l mannitol. these results indicated that the ms composition with sucrose concentration and the addition of hydrolyzed casein significantly enhance hypericin production in the calli and shoots.conclusion: overall, optimization of ms via adjustments to sucrose and the incorporation of hydrolyzed casein increased the production of hypericin, glands, and red pigments in h. perforatum.