Oral Administration of Garcinia dulcis Flower Extract Lowers Arterial Blood Pressure of 2-kidneys-1-clip Renovascular Hypertensive Rat

Abstract

The hexane insoluble fraction of the Garcinia dulcis (GD) flower extract comprises mainly camboginol and morelloflavone which possess potent in vivo and in vitro antioxidant properties. This study aimed to evaluate the effects of 4-week oral administration of GD flower extract on the arterial blood pressure (ABP) and the excretory function of the kidney in the 2-kidneys-1-clip (2K1C) renovascular hypertensive rats (total=12) compared to sham operated (SO) normotensive Wistar rats (total=12). Four weeks after hypertensive-induced surgery, either 50 mg/kg BW GD flower extract or vehicle was orally administered to the 2K1C or SO groups (n=6/group) daily for four weeks. ABP and the renal excretory function were studied in anesthetized rats, and expression of endothelial nitric oxide synthase (eNOS) mRNA in the isolated thoracic aorta were measured. In the 2K1C rats, GD flower extract significantly decreased ABP while increased significantly eNOS mRNA levels. GD flower extract did not exert a diuretic effect in either SO and 2K1C rats since there was no change in observed urine excretion, but it did tend to attenuated the renal tubular damage caused by renovascular hypertension. GD flower extract was anti-hypertensive in this model of renovascular hypertension and problably acts via the endothelial nitric oxide signaling pathway.

Garcinia dulcis Flower Extract Alters Gut Microbiota and Fecal Metabolomic Profiles of 2K1C Hypertensive Rats

“…The involvement of the gut microbiota in the regulation of hypertension in 2K1C models has been previously established [ 17 ]. Our findings agree with previous studies [ 6 ] that BPs were lower in the 2K1C hypertensive group but not the normotensive group after treatment with GD extract. The proposed anti-hypertensive effects of GD extract include anti-inflammatory, NO-dependent vasorelaxation and diuresis [ 6 ].…”

“…Our findings agree with previous studies [ 6 ] that BPs were lower in the 2K1C hypertensive group but not the normotensive group after treatment with GD extract. The proposed anti-hypertensive effects of GD extract include anti-inflammatory, NO-dependent vasorelaxation and diuresis [ 6 ]. We therefore sought to determine if these conditions could affect the gut microbiota.…”

“…The hexane-insoluble fraction of the GD flower extract composed of 2 bioactive compounds, morelloflavone and garcinol (aka. Camboginol), exhibited anti-hypertensive and diuretic properties in a 2K1C RVH model [ 6 ]. Activation of RAS in the 2K1C RVH model contributed to changes in water and electrolyte balance and upregulated the sympathetic nervous system, which induced an elevated BP.…”

“…After acclimatization, rats were randomly divided into two groups (12 animals each), for either 2K1C or SO, to develop a hypertensive or normotensive rat model, respectively. The operative procedure was performed as previously described [ 6 ]. In brief, rats were anaesthetized via inhalation of isoflurane according to a standard protocol.…”

“…The major bioactive compounds of GD fruit are morelloflavone and garcinol [ 3 ], which have hepatoprotective and anti-proliferative properties [ 4 , 5 ]. The hexane-insoluble fraction of the GD flower extract, which is mainly composed of camboginol and morelloflavone, can lower the arterial blood pressure of 2-kidney-1-clip (2K1C) renovascular hypertensive rats [ 6 ]. Camboginol and morelloflavone have antioxidant properties as effective scavengers of the DPPH (2,2-diphenyl-l-picrylhydrazyl) radical and the nitric oxide radical [ 3 , 5 ].…”