Experimental design
The experiment was conducted on total of fifteen male rats (12 months old as ageing sample, N=12), plus young rats as a control (N=3), divided into five groups of three rats per group as follows: Group 1 (exosomes only group) contains old rats that were administered intragastrically with empty exosome from mare’s milk once daily for a week. Group 2 (quercetin-loaded exosomes) has old rats administered intragastrically with quercetin-loaded exosomes from mare’s milk (quercetin concentration 2 mg/ml, volume administered was 0.5ml per rat, equating to 1mg of quercetin per rat) once daily for a week. Group 3 (quercetin only) has old rats administered intragastrically with free quercetin (quercetin concentration 2 mg/ml, volume administered was 0.5 ml per rat, equating to 1 mg of quercetin per rat) once daily for a week. Group 4 (control- untreated old rats) contains old rats that were administered intragastrically with drinking water (manipulation control) at a volume of 1 ml per rat. The fifth group (control- untreated young rats) has young rats that were administered intragastrically with drinking water once daily for a week. On the conclusion of the experiment day 8, animals were killed and three major organs were harvested for analysis including the heart, kidneys, and liver. Organs were preserved by immersion in 10% neutral buffered formalin.