Propylparaben

Propylparaben (Propyl parahydroxybenzoate) is an antibacterial preservative that can be produced by plants and bacteria. Propylparaben is commonly used in cosmetics, pharmaceuticals and foods. Propylparaben disrupts follicular growth and steroidogenic function by altering cell cycle, apoptosis and steroidogenic pathways. Propylparaben also reduced sperm count and motility in rats^{[1][2][3][4][5][6]}. In Vitro: Propylparaben protects isolated adult rat cardiomyocytes from ischemia-reperfusion injury. Propylparaben (500 μM; 10 min) significantly reduces cell death induced by 45 minutes of sustained ischemia and 15 hours of reperfusion^[4].
Propylparaben (250 μM, 500 μM) reversibly blocks voltage-gated sodium channels in a concentration- and voltage-dependent manner^[4].
Propylparaben (0-1 μM; 48 h) reduces basal lipolysis of mature 3T3-L1 white fat cells, such as insulin-stimulated glucose uptake. But does not change the base 2-NBDG uptake^[5].
In Vivo: Propylparaben (7.5 mg/kg/day; po; 8 months) treats female mice and significantly alters the estrus cycle, hormone levels, and ovarian reserve, accelerating ovarian aging in adult mice. Studies have demonstrated that melatonin supplementation can prevent proylparaben induced granulosa cell steroid production dysfunction^[6].