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This present study was to evaluate the protein tyrosine phosphatase 1B (PTP1B) inhibitory activity of nine diterpenes isolated from seeds of Phalaris canariensis, as well as their effect on strepto...

Diabetes mellitus (DM) is a chronic progressive systemic disease caused by a metabolic disorder. In recent years, a large number of studies have shown that certain traditional Chinese medicines and their bioactive ingredients have obvious hypoglycemic effects. This literature review focuses on medicine food homology (MFH) and medicinal health food (MHF) species used in China with a hypoglycemic function and emphasizes the bioactive ingredients and their pharmacological effects. The bioactive ingredients of MFH and MHF have been divided into six categories: saponins, flavonoids, terpenoids, alkaloids, polysaccharides, and others; and their sources, models, efficacy, and mechanisms of action have been described. It is noteworthy that the mechanisms of the bioactive ingredients of MFH and MHF with hypoglycemic effects have been summarized as follows: a) insulin-mimetic effects and restoration of the damaged pancreas; b) effect on glucose metabolism; c) increased insulin sensitivity and improved insulin resistance; and d) regulation of intestinal flora. We conclude that this review provides useful data and information to support the further investigation and application of MFH and MHF to treat DM.

Artemisia sieberi a member of Compositae family is an endemic species in Iran and commonly named “desert worm wood” or “dermaneh”. It has some pharmacological activities such as antimicrobial, antinociceptive, insecticidal and hypoglycemic effects as its traditional uses and used for treatment of malaria and coccidiosis.

As a percutaneous sustained-release preparation, insulin micropiles (MPs) were prepared with biodegradable polymers poly(lactic acid) (PLA), poly(ϵ-caprolactone) (PCL) and poly(lactic-co-glycolic acid) (PLGA) as the base. The obtained PLA, PCL, and PLGA MPs of which the insulin:polymer ratio was 1:2 were administered to rat skin at 40 IU/kg and hypoglycemic effects measured for 6 days. The order of the hypoglycemic effect was PLAPCLPLGA. PLA MP showed the strongest hypoglycemic effect (2 days). The hypoglycemic effect of insulin PLA MP was dependent on the formulation; the order was insulin:PLA (2:1)insulin:PLA (1:1)insulin:PLA (1:2). As the ratio of insulin to the polymer base increased, the hypoglycemic effect increased. The area above the plasma glucose levels vs. time curves for 6 days from insulin:PLA (2:1) MPs, 10, 20, 30, and 40 IU/ kg, were 249 ± 108, 2003 ± 379, 3960 ± 794, and 6311 ± 726%·h. A dose-dependent hypoglycemic effect was obtained at 10-40 IU/kg and pharmacological availabilities were 11.1%, 44.5%, 58.6%, and 70%, respectively. Insulin:PLA (2:1) MP showed high plasma insulin level, 86.9-134.7 IU/mL, for 3 days. There was no damage to rat skin. These results suggest the usefulness of insulin:PLA (2:1) MP as a sustained-release percutaneous delivery system for insulin.

Hypertension and non-insulin-dependent diabetes mellitus (NIDDM) often occur simultaneously and the combination requires vigorous control of hypertension. This can generally be achieved by a combination of antihypertensive drugs. The present study examines the antihypertensive and possible hypoglycemic effects of combined therapy with endothelin A (ETA) receptor antagonist LU-135252 and angiotensin-converting enzyme (ACE) inhibitor trandolapril in male Cohen-Rosenthal Diabetic Hypertensive (CRDH) rats.Rats were divided into four groups as follows: group I served as control; group II--LU-135252 30 mg/kg/day; group III--trandolapril 0.1 mg/kg/day and group IV--both LU-135252 30 mg/kg/day and trandolapril 0.1 mg/kg/day. Systolic blood pressure (SBP) and plasma glucose levels were evaluated at the beginning of the experiment and after 2, 4 and 6 weeks.SBP decreased significantly in all treated groups after 2, 4 and 6 weeks of treatment compared to baseline. Maximum decrease was in group IV (combination) from 174.8+/-3.7 to 136.1+/-2.4 mmHg (22%) (p0.0001); in group III (trandolapril) from 165.8+/-2.7 to 137.5+/-2.9 mmHg (17%) (p=0.0002); and in group II (LU-135252) and from 169.1+/-3.1 to 147.8+/-2.5 mmHg (12%) (p=0.0004). Glucose levels in plasma decreased significantly after 6 weeks of treatment. Maximum decrease was in group IV: from 501.0+/-42.8 to 178.6+/-7.3 mg/dl (62%) (p0.0001); in group III from 428.2+/-47.7 to 146.8+/-5.6 mg/dl (63%) (p0.0001); and in group II from 491.2+/-39.3 to 272.2+/-28.3 mg/dl (42%) (p=0.0002).The SBP decrease was additive when both drugs were given together. Thus, combination of ETA antagonist and ACE inhibitor appears to offer a rational fixed-dose antihypertensive therapy, which is superior to that of either drug alone. The decrease in glucose level, which was the least impressive while on LU-135252 alone, was more prominent during combination after 2 weeks, although without further decrease.

Prosopis fracta (Leguminosae) has been used in Jordanian folk medicine as a hypoglycemic and hypotensive agent. The hypoglycemic activity of an aqueous solution of the lyophylized root extract of Prosopis fracta was tested in normoglycemic and streptozocin-induced hyperglycemic rats. Results indicate that the root extract caused significant reductions in blood glucose concentration when given orally.

Polysaccharide fractions of the leaves of a number of Aloe species significantly reduced blood sugar level in mice. Activity-directed fractionation of the polysaccharide fraction from Aloe arborescens Mill. var. natalensis (Wood, et Ev.) Bgr. leaves yielded two glycans, arborans A and B, which elicited marked hypoglycemic effects in normal and alloxan-induced hyperglycemic mice.

A polysaccharide fraction of the Oriental crude drug “ninjin” (ginseng), Panax ginseng roots from China, significantly lowered blood sugar level in mice. Activity-guided fractionation of the fraction furnished four glycans, panaxans M, N, O and P, which exerted hypoglycemic effects in normal and alloxan-produced hyperglycemic mice.