(446b) Target-Specific Delivery of Polyphenolic Compounds for Mitigating Harmful Algal Blooms

Harmful algal blooms (HABs) represent significant ecological and economic risks globally, affecting both aquatic ecosystems and human health. Traditional methods of controlling HABs often rely on the direct application of algaecides, which affect non-target organisms and ecosystems. Therefore, there is a growing interest in finding sustainable alternatives with target-specific delivery for HAB mitigation. Recently, numerous studies have highlighted the effectiveness of polyphenolic compounds in inhibiting the proliferation of HABs. Polyphenols, known for being naturally derived and environmentally benign, are promising candidates for HAB mitigation. However, their mechanism of action is not thoroughly investigated. Conventionally known as antioxidants, recent findings suggest polyphenols can act as prooxidants, releasing small amounts of hydrogen peroxide which later produces hydroxyl radicals through Fenton-type reactions within cells. Hydroxyl radicals induce lipid peroxidation and DNA oxidative damage, eventually resulting in loss of cellular viability. We hypothesize that hydrogen peroxide generated from selected polyphenols is effective as an algaecide and our objective is to exploit this through a target-specific delivery system. Our work investigates the effectiveness of natural, inexpensive polyphenols, gallic acid and propyl gallate, against HABs. Initial results show these polyphenols effectively target Karenia Brevis cells, reducing cell viability and inhibiting algal growth. We propose a strategy for targeted delivery of these algaecides in a controlled manner. Overall, employing polyphenols presents a sustainable and eco-friendly approach to HAB mitigation, contributing to water resource management and environmental conservation efforts.