Animals must maintain proper balance between energy intake and expenditure. Recently, we descovered the enzymaticco-factor tetrahydrobiopterin (BH4) inhibits feeding in Drosophila. BH4 biosynthesis requires the sequential action of theconserved enzymes Punch, Purple, and Sepiapterin Reductase (Sptr). Although we observe increased feeding upon lossof Punch and Purple in the adult fat body, loss of Sptr must occur in the brain. We found Sptr expression is requiredin four adult brain neurons that express NPF, the fly homologue of the vertebrate appetite regulator NPY. Mechanistically,we found BH4 deficiency reduces NPF levels, while excess BH4 increases NPF accumulation without altering its expression.
The antibiotic and antioxidant effect of botanical antimicrobial agent-citrus product(BAAC) prepared from citrus fruits were investigated by using fishmeats made from pollack and ascidian fillet. We inoculated Salmonella typhi into fishmeats that were aferwards treated with BAAC varying the concentration level (50-500ppm) including the control not-treated with BAAC. While specimens were stored at 5 for designated period, we measured changes of total number of bacteria, peroxide level and textural properties. In addition, we performed organoleptic examination, focusing on appearance, texture and odor for fishmeats treated with BAAC and stored for designated period. For pollack and ascidian fishmeats, the initial total number of bacteria were 3.7l0CFU/g and 7.5l0CFU/g, respectively. After they were treated with 250 ppm of BAAC solution and stored for 5 days at 5, the figures reduced to 2.5l0CFU/g and 8.410CFU/g. No bacteria were found in fishmeats treated with above 500 ppm of BAAC, which remarkably proved antibiotic effect of BAAC solution. Furthermore, all the BAAC-treated specimens exhibited notable antioxidant effect. Fishmeats which were previously treated with 500 ppm of BAAC solution and stored for 30 days at 5, showed the lower peroxide level of 16.5 meq/kg than 68.9 meq/kg in the control of pollack and 21.2 meq/kg than 80.7 meq/kg in the control of ascidian. In the results of texture and organoleptic evaluation we could also observe good effects of BAAC on maintaining the freshness of fisher products.