Propylene glycol-based green extraction of polyphenols from industrial hemp stems: process optimization and bioactivity assessment

What if the discarded stems of industrial hemp could become a treasure trove of skin-healing, bacteria-fighting compounds?

Industrial hemp is a superstar crop, but its stems often end up as waste after fiber production. Now, scientists have found a way to turn this byproduct into a goldmine of bioactives using a green, propylene glycol-based solvent and ultrasound assistance. By tweaking extraction conditions—30 minutes, a solvent-to-solid ratio of 28.25 mL/g, and a 32.72% propylene glycol concentration—they produced an extract packed with polyphenols and other beneficial compounds.

This extract, called HUPG, showed impressive antioxidant activity and contained 18 phytochemicals, including isofeuric acid, m-coumaric acid, and chelidonic acid. It also fought off common pathogens like Staphylococcus aureus and Escherichia coli, and reduced inflammation by inhibiting 5-lipoxygenase and scavenging nitric oxide radicals. In lab tests, HUPG curbed nitric oxide production in immune cells and accelerated wound closure in skin cells, with a 51.92% closure rate at 10 mg/mL.

These findings suggest that hemp stems, once discarded, could be a sustainable source for cosmetics and pharmaceuticals. The study not only adds value to agricultural waste but also opens doors to natural, eco-friendly ingredients.

Key Points

• Green extraction using propylene glycol and ultrasound boosts polyphenols from hemp stems.
• HUPG extract fights bacteria, reduces inflammation, and accelerates wound healing.
• 18 phytochemicals identified, including isofeuric acid, m-coumaric acid, chelidonic acid.