Nutraceutical intervention protects against bacterial and chemical-induced gastrotoxicity in a non-mammalian model, Galleria mellonella

Abstract

Preparations of the fungus Cordyceps sinensis and bovine colostrum are considered nutraceuticals due to their anti-inflammatory, repair and gut alimentation properties in mammalian models. To reduce the reliance on rodents in routine experimentation, we gauged the capacity of nutraceuticals to alleviate gastric damage in an insect surrogate, Galleria mellonella. Larvae were reared on standard or supplemented diets – 10% (w/w) colostrum, 10% (w/w) C. sinensis, or 5% + 5% each – prior to receiving an oral dose of the NSAID indomethacin (30 mg/kg) or challenged with the bacterial pathogen Campylobacter jejuni (1-3 x106) via two inoculation routes. Insects reared on a cordyceps-supplemented diet proved most resistant to indomethacin-induced gut leakiness, and displayed stable health indices after C. jejuni challenge (~77% survival). Insects reared on a colostrum-supplemented diet also showed recalcitrance in the gut, but were more sensitive to C. jejuni when injected directly into the body cavity (50% survival). The nutraceutical blend yielded improved health outcomes when compared to the standard diet, but was not as effective as either nutraceutical alone. Our findings represent clear evidence that insects were more resistant to known chemical and microbial agitators when reared on nutraceutical-supplemented diets – toxicological endpoints that are shared with vertebrate studies.