Gamma-aminobutyric acid (GABA) is known for its blood pressure-lowering effect. We investigated this function in spontaneously hypertensive rats (SHR) on sponge gourd chronic administration and attempted to increase GABA concentration in sponge gourd via pickling. A single oral dose of GABA (5-mg/10-mℓ/kg) or sponge gourd extract (containing 2-mg GABA/10-mℓ/kg) significantly decreased SHR blood pressure after 6 h postadministration (p<0.05). Compared to the control group, a significantly slower increase in blood pressure was observed after 7 to 10 weeks post GABA or gourd diet feeding (p<0.01), and this difference was maintained throughout the entire administrations. However, the GABA content in cut sponge gourd was doubled by vacuum-packing followed by refrigeration for 3 days. Moreover, there was an increment in GABA concentration due to monosodium glutamate (MSG) addition on pickled lyophilized gourd powder upon heating at 60℃ for 15 min at pH 5.5. Additionally, the concentration was enhanced thrice when fresh gourd was soaked in 0.2% MSG solution, vacuum-packed, and heated at 60℃ for 15 min. Taken together, sponge gourd containing GABA could lower blood pressure on SHR and its GABA concentration could be enhanced by pickling preservation.
