Feverfew (Tanacetum parthenium) is a well-known multi-functional plant with anti-inflammatory, cardiotonic, antiangiogenic, and anticancer effects. The therapeutic value of this plant is due to its phytochemical constitutes, especially parthenolide. Tissue culture techniques have been applied to improve the bioactive components of many herbal plants. Hence, this study, was carried out to establish a protocol for micropropagation of the feverfew plant and to quantify parthenolide content in its micropropagated and conventionally grown plants. To establish an aseptic culture, different concentrations of sodium hypochlorite (NaOCl) were investigated for seed surface sterilization. Besides, the effects of plant growth regulators (PGRs) on the callus induction, shoot organogenesis from callus and in vitro rooting were evaluated. Additionally, the parthenolide yield of the micropropagated and conventionally grown plants was determined by using high-performance liquid chromatography (HPLC). The results showed that surface sterilization of feverfew seeds with 6% NaOCl for 15 min obtained 65.00 ± 2.69% aseptic seeds. Murashige and Skoog (MS) medium supplemented with 0.4 mg/L thidiazuron (TDZ) and 2 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) resulted in 86.00 ± 1.72% callus induction. The highest number of shoots (5.00 ± 0.15) per explant was obtained in the treatment of MS medium supplemented with 5 mg/L zeatin. MS medium fortified with 3 mg/L indole-3-butyric acid (IBA) produced the maximum number of roots per plantlet (8.90 ± 0.35). A total of 90% of the micropropagated plantlets survived when planted in perlite + peat moss (1:1 v/v); the micropropagated plantlets were successfully established in the ex vitro conditions. According to parthenolide analysis, its level was significantly higher in the micropropagated plants than conventionally grown plants. Among different solvents, ethanolic extraction obtained the highest parthenolide content of the feverfew plant. Hence, it can be concluded that micropropagation of feverfew could be applied to produce disease-free planting materials and to improve the parthenolide content of the feverfew plant.

In order to investigate the possibility for in in vitro fast regeneration of Dianthus caryophyllus, different concentrations of Kinetin (Kin), 2,4-Dichlorophenoxy Acetic Acid (2,4-D) had been tested for induction of callus by leaves and stems explant using Murashige and Skoog (MS) medium. After two months in culture, response callus in the induction rate, fresh and dry weight, texture and color were evaluated. MS medium that contained 4.5 mg.L-1 2, 4-D was suitable for callus induction with leaf explants. The combination of 0.4 mg.L-1 Kin and 2.0 mg.L-1 2, 4-D also demonstrated a wonderful induction of callus on stem explants. In addition to the culture medium complemented by Kin and 2, 4-D, the influence of Zeatin at various concentrations (0.0, 0.4, 0.8 or 1.0 mg.L-1) was assessed. In MS medium that contained 0.4 mg.L-1 Kin+ 2.0 mg.L-1 2,4-D+ 1.0 mg.L-1 Zeatin, rapid callus induction and also more callus proliferation from stem explants were detected. Results indicate on callus induction that, Zeatin was more successful than Kin or 2, 4-D, but other combinations directly developed a shoot. Callus obtained from stems explant was friable, white and yellow, while callus from leaf explants was green.

Washingtonia filifera is important for its ecological, economic, cultural, horticultural, ornamental, and medicinal potential. Elicitation of in vitro cultures presents a promising and efficient method for the large-scale production of valuable bioactive compounds. This study assessed the effect of chitosan concentration (0, 20, 40, 60, 80, 100 mg L⁻¹) on biomass growth [fresh weight (FW), dry weight (DW)] and phytochemical profile [total phenolic content (TPC), total flavonoid content (TFC), DPPH antioxidant activity, total phenolic productivity (TPP), total flavonoid productivity (TFP)] in W. filifera callus and cell suspension cultures. Among different plant growth regulator combinations tested, 3 mg L⁻¹ 2,4-D + 0.5 mg L⁻¹ 2ip gave higher callus induction (90%) (MS medium, 12 weeks). A maximum growth curve (FW: 180 mg) of cell suspension culture was achieved 7 weeks after initiation (shaker at 90 rpm for 24 h). Cell suspension exhibited higher FW, DW, TPC, TFC, DPPH, TPP, and TFP than callus, while flavonoid production was higher than phenolic production. FW and DW were higher in both systems, with 40 mg L⁻¹ chitosan. Chitosan at 60 mg L⁻¹ best enhanced the phytochemical profile of both the 4-week solidified callus and the 7-week liquid cell suspension (TPC: 29.9 and 32.1 mg GAE g⁻¹ DW; TFC: 40.5 and 56.1 mg QE g⁻¹ DW; TPP: 969.2 and 1122.6 mg L⁻¹; TFP: 1313.9 and 1521.7 mg L⁻¹; DPPH: 87.4 and 92.3%), respectively, while 40 mg L⁻¹ chitosan was equally effective regarding DW, TFC, and TFP in cell suspension. Chitosan elicitation provides a powerful strategy to upregulate phenolic and flavonoid biosynthesis in W. filifera in vitro systems, conferring superior antioxidant potential. The identification of peak elicitation parameters (chitosan concentration, exposure time) allows for the targeted enhancement of bioactive compound yields, suggesting a viable path for industrial bioproduction and commercialization in pharmaceuticals, nutraceuticals, and functional foods, leveraging bioreactor technology for efficient scale-up.