No abstract

Cell culture feeds optimization is a critical step in process development of pharmaceutical recombinant protein production. Amino acids are the basic supplements of mammalian cell culture feeds with known effect on their growth promotion and productivity. In this study, we reported the implementation of the Plackett-Burman (PB) multifactorial design to screen the effects of amino acids on the growth promotion and productivity of a Chinese hamster ovary DG-44 (CHO-DG44) cell line producing bevacizumab. After this screening, the amino acid combinations were optimized by the response surface methodology (RSM) to determine the most effective concentration in feeds. Through this strategy, the final monoclonal antibody (mAb) titre was enhanced by 70%, compared to the control group. For this particular cell line, aspartic acid, glutamic acid, arginine and glycine had the highest positive effects on the final mAb titre. Simultaneously, the impact of the designed amino acid feed on some critical quality attributes of bevacizumab was examined in the group with highest productivity. The product was analysed for N-glycan profiles, charge variant distribution, and low molecular weight forms. The results showed that the target product quality has been improved using this feeding strategy. It was shown how this strategy could significantly diminish the time and number of experiments in identifying the most effective amino acids and related concentrations in target product enhancement. This model could be successfully applied to other components of culture media and feeds.

The extract from Artemisia annua, containing artemisinin, has been proven active against multidrug resistant Plasmodium falciparum in previous studies. The purpose of this paper was to study five Artemisia species from Iran for their in vitro and in vivo antimalarial property and detection of artemisinin in the active species by chromatographic and spectroscopic methods including nuclear magnetic resonance (NMR) spectroscopy. Dried plants were extracted by 80% ethanol, and total extracts were investigated for antiplasmodial property and artemisinin content by TLC, HPLC, and (1)H-NMR techniques. Two plants (A. annua L. and Artemisia absinthium L.) showed good antiplasmodial activity against multidrug resistant and sensitive strain of P. falciparum. A. absinthium and A. annua at concentrations of 200 mg/kg for 4 days reduced parasitemia in BALB/C mice infected with Plasmodium bergei by 94.28% and 83.28%, respectively, but we could not detect artemisinin in all plants studied in this research. The antiplasmodial property of these two herbs is possibly related to essential oils that present in high amounts in their extracts.