Investigation of the Distribution and Content of Acetylcholine, a Novel Functional Compound in Eggplant

Abstract

Eggplants are rich in acetylcholine (ACh), which can improve high blood pressure and negative psychological states. However, information on ACh content in individual parts of eggplant and the changes in ACh content during eggplant development is limited. Therefore, we investigated the ACh content in various parts of eggplant, namely, the leaf, root, bud, calyx, ovary, fruit, exocarp, mesocarp, partition, placenta, core, fruit base, fruit center, and fruit top in 26 eggplant varieties. Furthermore, the effect of heat treatment on ACh content was investigated. The ACh content significantly differed among the eggplant varieties. The difference between the varieties with the highest and lowest ACh content was 100-fold (Tosataka: 11 ± 0.61 mg/100 g fresh weight (FW) and Ryoma: 0.11 ± 0.046 mg/100 g FW, respectively). Eggplant fruit presented the highest ACh content (4.8 mg/100 g FW); it was three times higher than that in other parts combined (1.6 mg/100 g FW). The root contained the lowest ACh content among all parts. The ACh content increased with growth after flowering. The ACh content in the fruit 1.5 months after flowering was 400 times that in the ovary. ACh was uniformly distributed in eggplant flesh. Heat treatment did not cause ACh loss in eggplant. Thus, eggplant is an excellent raw material for functional foods.

Antihypertensive Mechanism of Orally Administered Acetylcholine in Spontaneously Hypertensive Rats

“…The antihypertensive compound ACh is ingested daily from various foods and may mildly reduce BP [6,8,9]. In this study, we observed a reduction in BP and SNA following oral administration of ACh in free-moving SHRs.…”

“…We recently showed that 19 popular cultivated crops contain ACh, and the content in eggplant was 2900-fold higher than the average ACh content in other crops [8]. Subsequently, it was estimated that the ACh present in 61 g of eggplant is equivalent to the effective dose of 2.3 mg, which can improve BP [9], indicating that ACh derived from eggplant influenced BP following daily ingestion.…”

Evaluation of the Antihypertensive Activity of Eggplant Acetylcholine and γ-Aminobutyric Acid in Spontaneously Hypertensive Rats

“…Monitoring was performed at the following mass-to-charge ratio ( m / z ) transitions: 146.15 → 87.10 (ACh) and 104.15 → 87.20 (GABA). The methodology adopted has been described in our previous study, in which we used the standard addition method to measure the concentrations of ACh and GABA [ 38 ].…”

Differential Antihypertensive Effects of Oral Doses of Acetylcholine between Spontaneously Hypertensive Rats and Normotensive Rats

“…A wide variety of eggplant species contain sufficient levels of ACh to achieve the effective daily intake amount. Additionally, ACh is distributed uniformly in the fruit and is stable under Foods 2021, 10, 2107 2 of 10 heat [10]. Eggplant is a major agricultural product that is cultivated worldwide, and the antihypertensive effect of ACh is expected to be exploited globally.…”