Melon rind may hold potent cure

Could a cure to sickle-cell-related deficiencies lie in the rind of the honey-like bounty of Mediterranean summers? Scientists in the US would have us believe so with new research that suggests melon rinds contain citrulline, an amino acid that plays an important role in the human body's urea cycle.

Citrulline, an amino acid that removes nitrogen from the blood and helps convert it to urine, helps create arginine, another amino acid of which some people are deficient.

According to Agnes Rimando, a research chemist at the US Agricultural Research Service (ARS), the recent study of melon rinds could lead to the production of rind-based extract or dietary-supplement products that address arginine- or sickle-cell-related deficiencies.

In the urea cycle, citrulline combines with another acid to create arginine. Citrulline is a 'non-essential' amino acid, meaning it need not be ingested because the body produces it. Amino acids - the body's building blocks - are produced when digestion breaks down protein.

Disorders in the urea cycle can lead to a lethal buildup of proteins such as ammonia in the bloodstream. Arginine or citrulline are often recommended to address these disorders.

Arginine boosts nitric oxide, which relaxes blood vessels and could consequently help treat angina and other cardiovascular problems. Arginine has also been credited with boosting muscle growth, improving wound healing, combating fatigue, stimulating the immune system, curing impotence and fighting cancer.

Rimando maintains that the discovery came early during a study - in collaboration with plant physiologist Penelope Perkins-Veazie at a ARS laboratory in Oklahoma - that was aimed at determining the citrulline content of different watermelon varieties.