Strong Antihyperglycemic Effects of Water-Soluble Fraction of Brazilian Propolis and Its Bioactive Constituent, 3,4,5-Tri-<i>O</i>-caffeoylquinic Acid

Abstract

To clarify the suppression of postprandial blood glucose rise via a a-glucosidase (AGH) inhibitory action by natural compounds, propolis was examined in this study. A single oral administration of propolis extract (50% methanol fraction on XAD-2 column chromatography) in Sprague-Dawley rats demonstrated a potent antihyperglycemic effect with the significant AUC 0-120 min reduction of 38% at a dose of 20 mg/kg compared to that of controls. Among the active compounds isolated from the fraction, 3,4,5-tri-caffeoylquinic acid was found to be a prominent candidate that exerts the effect and shows a strong maltase-specific inhibition with an IC 50 value of 24 m mM. In addition, the noncompetitive inhibition power apparently increased with the number of caffeoyl groups bound to quinic acid.

Effecs of Cypermethrin on Some Biochemical Changes in Rats: The Protective Role of Propolis

“…This result, as indicated above, may be related to the dose administered and the single administration. As in a study conducted by Matsui et al [28] with rats, propolis was determined to cause a decrease in glucose levels, and also Fuliang et al [12] reported it decreased triglyceride and cholesterol levels in rats.…”

Phytochemical analysis and antioxidant activities of Trigona Apicalis propolis extract

“…The main bioactive substances in propolis like phenolic compounds have pharmacological effects, including antioxidation and anti-diabetes [25]. Based on this experiment, it showed that Total Flavonoid Content (TFC) was higher than Total Phenolic Content (TPC) ( Table 1).…”

Effect of Brazilian green propolis in patients with type 2 diabetes: A double-blind randomized placebo-controlled study

“…Second, the dose of propolis may not have been sufficient. Numerous studies report the efficacy of propolis on diabetes; however, the majority are animal experiments and administered doses of propolis were extremely high (such as 50-300 mg/kg of the body weight) (8)(9)(10)(28)(29)(30). Therefore, if a higher dose of propolis was administered to patients, the effect of propolis on glucose metabolism may take effect.…”

“…Propolis presents numerous biological and pharmacological properties, such as immunomodulatory, antitumor, anti-inflammatory and antioxidant activity (7). In previous years, a number of studies have identified that propolis has hypoglycemic effects in animal models with type 2 diabetes (8)(9)(10). To the best of our knowledge, however, there have been no studies regarding these effects in human.…”