Microhemodynamic indices to evaluate the effectiveness of herbal medicine in diabetes: A comparison between alpha-mangostin and curcumin in the retina of type 2 diabetic rats
Affiliations: [a] Department of Physiology, Faculty of Medicine, Srinakharinvirot University, Bangkok, Thailand
| [b] Biomedical Science Program, Faculty of Medicine, Srinakharinvirot University, Bangkok, Thailand
| [c] National Cardiovascular Center Research Institute, Osaka, Japan
Correspondence:
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Corresponding author: Amporn Jariyapongskul, Department of Physiology, Faculty of Medicine, Srinakharinvirot University, Bangkok 10110, Thailand. Tel.: +66 81 7581222; E-mail: ampornswu@gmail.com.
Abstract: OBJECTIVE:This study was aimed to develop microhemodynamic indices to evaluate the effectiveness of herbal medicine in diabetic tissues. METHODS:Male Sprague-Dawley rats were divided into four groups: normal control rats (Control), type 2 diabetic rats without (DM2) and with supplementation of alpha mangostin (DM2-MG) or curcumin (DM2-CUR). Alpha-mangostin or curcumin (200 mg/kg BW) were fed followed by i.p. injection of streptozotocin (STZ). Mean arterial pressure (MAP) and retinal blood flow (RBF) were measured and retinal flow resistance (RFR) was calculated. Three indices were developed to evaluate the effectiveness of herbal medicines in RFR-MAP diagram based on experimental data of MAP and RFR in type 2 diabetic rats. These indices are α, β, and γ where α is a ratio of reduction in MAP, β is a ratio of reduction in RFR increasing with MAP increase, and γ indicates a ratio of reduction in RFR. RESULTS:The elevated MAP and RFR and decreased RBF were observed in DM2 rats.Interestingly, alpha-mangostin or curcumin supplementation significantly increased RBF while decreased MAP and RFR. Using α, β and γ indices, it was found that alpha-mangostin is more effective than curcumin in type 2 diabetic retina. CONCLUSIONS:These microhemodynamic indices may be useful to compare various herbal medicines in different tissues.
