PEG modification of Amorfrutin B from Amorpha fructicosa increases gastric absorption, circulation half-life and glucose uptake by T3T-L1 adipocytes.

Through a simple PEG-conjugation of the natural product Amorfrutin B, we enhanced its pharmacokinetic profile. The PEGylated molecule displayed significantly improved gastrointestinal absorption (p<0.05) and had a longer systemic circulation life (p<0.05). Oral glucose tolerance study showed PEGylated Amorfrutin B displayed longer protection against oral glucose load compared to Amorfrutin B (p<0.05). It also showed significant improvement in glucose uptake in-vitro by T3T-L1 adipocytes (p<0.05). The PEGylated molecule also showed reduced propensity of crossing the blood brain barrier and accumulating in the brain (p<0.05). It also showed reduced accumulation in the adipose tissue. Preliminary liver and kidney toxicity screening showed no significant alteration in liver or kidney function of Amorfrutin B or its PEGylated form. In conclusion, PEG modification can be an attractive strategy to reduce lipophilicity and enhance pharmacokinetic properties of natural products, derived from traditional medicine.