A Compound in Tropical Fruit Relaxes Blood Vessels — Scientists Now Know Exactly How
The rind of the mangosteen, a tropical fruit, contains a compound that widens blood vessels.
Polyphenols — plant compounds found in wine, berries and tea — have long been associated with health benefits, but the mechanisms behind those benefits often remain vague. For alpha-mangostin, the primary active compound in Garcinia mangostana, that vagueness is starting to lift. A new study published in eLife shows how alpha-mangostin relaxes blood vessels by acting on specific potassium channels in the walls of those vessels.
These channels — technically known as BK channels, or large-conductance potassium channels — sit in the smooth muscle cells that wrap around blood vessels. When they open, the muscle cell relaxes and the vessel dilates, lowering blood pressure. The researchers identified precisely which amino acids within the channel alpha-mangostin targets: two specific gating residues in the so-called S6 domain, the structural element that governs whether the channel is open or closed.
Why molecular precision matters
The significance of that precision is hard to overstate. In pharmacology, a long-standing principle holds that without a known molecular target, even a promising compound is little more than anecdote. Now that alpha-mangostin has an identifiable point of action on a physiologically relevant channel, it becomes a serious candidate for further research — and potentially for drug design.
High blood pressure is one of the leading risk factors for cardiovascular disease, the world’s top cause of death. It is also strongly linked to accelerated biological aging: chronically elevated blood pressure damages blood vessels, the heart and kidneys, and increases the risk of dementia. Identifying new molecular entry points for blood pressure regulation is therefore directly relevant to longevity research.
The caveats worth keeping in mind
Caution is warranted. This is laboratory research — the experiments were conducted on isolated cells and tissue, not in humans. The path from an active compound in a test tube to a safe and effective drug is long and littered with failures. BK channels are also active in the brain and other organs, meaning a compound that activates them could produce unintended effects beyond blood vessels.
What remains is a more precise understanding of how a plant compound works at the molecular level. Whether that understanding eventually leads to a drug, a nutraceutical, or simply a better grasp of vascular biology — that remains to be seen.