Bromelain: a candidate to enhance wound healing after endonasal surgeries

In the present study, we investigated the topical bromelain's cytotoxic effects on mouse fibroblast NIH/3T3 cells via cell culture study.

In this cell culture study, Dulbecco's Modified Eagle Medium (DMEM) with fetal bovine serum (FBS, 10%) and penicillin/streptomycin (1%) was used as a cell growth medium for NIH/3T3 mouse fibroblast cells. MTT test was performed in 96-well plates seeded with NIH/3T3 cells 5x103/well and under standard cell culture conditions. Bromelain doses of 3.13 to 100 μM were administered to the wells and incubated for 24, 48, and 72 hours in the same cell culture conditions. For Confocal microscopic evaluation, NIH/3T3 cells were plated on cover slips in 6-well plates (105 cells/well) and treated with 100 μM concentration of bromelain for 24 h. Untreated cells were used as controls.

MTT results showed that bromelain is not cytotoxic on mouse fibroblast NIH/3T3 cells. All three incubation times of 24, 48, and 72 hours bromelain initiated cell growth. A statistically significant rise in cell growth was detected in the only applied highest dose of 100 μM bromelain for all incubation times except for 24 hours. The nontoxic effect was further investigated by using confocal microscopy by applying the highest bromelain dose of 100 μM to NIH/3T3 mouse fibroblast cells. Confocal micrographs showed that bromelain did not change the morphology of mouse fibroblast cells at the incubation time of 24h. In untreated cells and bromelain-treated cells, the nucleus of NIH/3T3 cells was undamaged and compact, and the cytoskeleton was fusiform and non-fragmented.

Bromelain is not cytotoxic on mouse fibroblast NIH/3T3 cells and enhances cell growth. If clinical trials will confirm this, it is possible that bromelain will be used topically in humans to enhance wound healing, in rhinosinusitis and chronic rhinosinusitis with nasal polyps and endonasal surgeries due to its anti-inflammatory effects.