ORCID Profile
0000-0002-5639-1667
Current Organisation
Walailak University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 10-2022
Publisher: Penerbit Universiti Kebangsaan Malaysia (UKM Press)
Date: 31-03-2022
DOI: 10.17576/JSM-2022-5103-18
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.
Publisher: College of Graduate Studies, Walailak University
Date: 11-10-2022
Abstract: Condensed tannins (CTs) extracted from various plants have been shown to possess antioxidant, antidiabetic, anthelmintic, anti-palatable and anti-diarrhea activity. Black currant (Ribes nigrum L.), a native plant of northern Europe and Asia, is rich in phenolic compounds, including CTs. Among the biological activities of CTs, their astringent property is likely to affect gastrointestinal motility. This study aimed to investigate the physiological effect of CTs from black currant (R. nigrum L.) leaves on isolated rat duodenal contraction. Duodenal segments were fixed in organ baths containing carbogen aerated Krebs solution at the resting tension of 0.7 - 0.8 g. The frequency, litude, and tone of duodenal contraction were recorded. Either CTs or acetylcholine (ACh) were cumulatively added into the bath at the concentration of between 0.001 - 10 µg/mL and 10–8 - 10–4 M, respectively. The mechanisms of CTs and ACh actions were studied using muscarinic receptor antagonist (atropine, 1.55×10–5 M) and calcium channel blocker (verapamil, 10–6 M). It is found that CTs at the concentration between 0.001 - 10 µg/mL had no direct effect on duodenal frequency, litude, and tone of contraction, whereas ACh showed a significant increase in tonic contraction, was suppressed by atropine. Interestingly, in the presence of atropine and verapamil, CTs showed a further significant decrease in the litude of duodenal contraction compared to the effect of these 2 blockers alone. It is concluded that CTs would synergize the activity of the muscarinic receptor antagonist and the calcium channel blocker at duodenal enteric neurons or smooth muscle membrane. However, the use of CTs from black currant (R. nigrum L.) leaves to treat gastro-intestinal disorders while having muscarinic receptor antagonist or calcium channel blocker need cautions. HIGHLIGHTS Black currant (Ribes nigrum L.), a native plant of northern Europe and Asia, is rich in phenolic compounds including condensed tannins (CTs) and their astringent property is likely to affect gastrointestinal motility CTs isolated from leaves of black currant (R. nigrum L.) at the physiological doses (0.001 - 10.0 µg/mL) have no direct effect on isolated rat duodenal contraction CTs may possess the synergistic or additive effect with either atropine, a nonselective muscarinic receptor, or verapamil, a calcium channel blocker on duodenal litude of contraction GRAPHICAL ABSTRACT
No related grants have been discovered for Siriphun Hiranyachattada.