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Long-term stable cell growth and production of vindoline, catharanthine, and ajmalicine of cambial meristematic cells (CMCs) from Catharanthus roseus were observed after 2 years of culture. C. roseus CMCs were treated with β-cyclodextrin (β-CD) and methyl jasmonate (MeJA) individually or in combination and were cultured both in conventional Erlenmeyer flasks (100, 250, and 500 mL) and in a 5-L stirred hybrid airlift bioreactor. CMCs of C. roseus cultured in the bioreactor showed higher yields of vindoline, catharanthine, and ajmalicine than those cultured in flasks. CMCs of C. roseus cultured in the bioreactor and treated with 10 mM β-CD and 150 μM MeJA gave the highest yields of vindoline (7.45 mg/L), catharanthine (1.76 mg/L), and ajmalicine (58.98 mg/L), concentrations that were 799, 654, and 426 % higher, respectively, than yields of CMCs cultured in 100-mL flasks without elicitors. Quantitative reverse transcription (RT)-PCR showed that β-CD and MeJA upregulated transcription levels of genes related to the biosynthesis of terpenoid indole alkaloids (TIAs). This is the first study to report that β-CD induced the generation of NO, which plays an important role in mediating the production of TIAs in C. roseus CMCs. These results suggest that β-CD and MeJA can enhance the production of TIAs in CMCs of C. roseus, and thus, CMCs of C. roseus have significant potential to be an industrial platform for production of bioactive alkaloids.

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A novel polysaccharide (LCP50W) with a molecular weight of 4.72 × 10(4) Da was isolated from the pulp tissues of Litchi chinensis . The chemical structure of LCP50W was characterized using physicochemical and instrumental analyses. The results indicated that the main chain of LCP50W consisted of (1→3)-linked β-L-rhamnopyranosyl, (1→6)-linked α-D-glucopyranosyl, and (1→2,6)-linked α-D-glucopyranosyl residues, which branched at O-6. The three branches consisted of (1→2)-linked α-L-rhamnopyranosyl, (1→3)-linked α-D-galactopyranosyl, and (1→3)-linked α-L-mannopyranosyl residues, terminated with (1→)-linked α-L-arabinopyranosyl residues, respectively. The in vitro immunomodulatory assay revealed that LCP50W promoted the proliferation of mouse splenocytes and enhanced the cytotoxicity of NK cells. LCP50W boosted the secretion of Th1 cytokine IFN-γ while it inhibited the secretion of Th2 cytokine IL-4; it also enhanced the expression of T-bet while it inhibited the expression of GATA-3. Additionally, LCP50W promoted the development of cell cycle toward the S phase.