Jing-Tian Xie

Anti-hyperglycemic effects of ginseng: Comparison between root and berry

Previous studies demonstrated that both ginseng root and ginseng berry possess anti-diabetic activity. However, a direct comparison between the root and the berry under the same experimental conditions has not been conducted. In the present study, we compared anti-hyperglycemic effect between Panax ginseng root and Panax ginseng berry in ob/ob mice, which exhibit profound obesity and hyperglycemia that phenotypically resemble human type-2 diabetes. We observed that ob/ob mice had high baseline glucose levels (195 mg/dl). Ginseng root extract (150 mg/kg body wt.) and ginseng berry extract (150 mg/kg body wt.) significantly decreased fasting blood glucose to 143 +/- 9.3 mg/dl and 150 +/- 9.5 mg/dl on day 5, respectively (both P < 0.01 compared with the vehicle). On day 12, although fasting blood glucose level did not continue to decrease in the root group (155 +/- 12.7 mg/dl), the berry group became normoglycemic (129 +/- 7.3 mg/dl; P < 0.01). We further evaluated glucose tolerance using the intraperitoneal glucose tolerance test. On day 0, basal hyperglycemia was exacerbated by intraperitoneal glucose load, and failed to return to baseline after 120 min. After 12 days of treatment with ginseng root extract (150 mg/kg body wt.), the area under the curve (AUC) showed some decrease (9.6%). However, after 12 days of treatment with ginseng berry extract (150 mg/kg body wt.), overall glucose exposure improved significantly, and the AUC decreased 31.0% (P < 0.01). In addition, we observed that body weight did not change significantly after ginseng root extract (150 mg/kg body wt.) treatment, but the same concentration of ginseng berry extract significantly decreased body weight (P < 0.01). These data suggest that, compared to ginseng root, ginseng berry exhibits more potent anti-hyperglycemic activity, and only ginseng berry shows marked anti-obesity effects in ob/ob mice.

Ginseng and Diabetes

Ginseng is a well-known medicinal plant used in traditional Oriental medicine. In recent decades, ginseng root has gained popularity as a dietary supplement in the United States. Ginseng has also been commonly used in Oriental medicine to treat diabetes-like conditions. The present review discusses the research on the anti-diabetic effects of ginseng and the possible mechanisms of its anti-diabetic actions.

Ginseng berry reduces blood glucose and body weight in db/db mice

In this study, we observed anti-diabetic and anti-obesity effects of Panax ginseng berry in adult C57BL/Ks db/db mice and their lean littermates. Animals received daily intraperitoneal injections of Panax ginseng berry extract at 150 mg/kg body wt. for 12 consecutive days. On Day 5, the extract-treated db/db mice had significantly lower fasting blood glucose levels as compared to vehicle-treated mice (180.5+/-10.2 mg/dl vs. 226.0+/-15.3 mg/dl, P < 0.01). On day 12, the extract-treated db/db mice were normoglycemic (134.3+/-7.3 mg/dl) as compared to vehicle-treated mice (254.8+/-24.1 mg/dl; P < 0.01). Fasting blood glucose levels of lean mice did not decrease significantly after treatment with extract. After 12 days of treatment with the extract, glucose tolerance increased significantly, and overall blood glucose exposure calculated as area under the curve (AUC) decreased 53.4% (P < 0.01) in db/db mice. Furthermore, db/db mice treated with extract (150 mg/kg body wt.) showed weight loss from 51.0+/-1.9 g on Day 0, to 46.6+/-1.7 g on Day 5, and to 45.2+/-1.4 g on Day 12 (P < 0.05 and P < 0.01 compared to Day 0, respectively). The body weight of lean littermates also decreased at the same dose of extract. These data suggest that Panax ginseng berry extract may have therapeutic value in treating diabetic and obese patients.

Effects of American Ginseng Berry Extract on Blood Glucose Levels in ob/ob Mice

In this study, we evaluated antihyperglycemic effects of American ginseng berry extract in diabetic ob/ob mice. Animals received daily intraperitoneal (IP) injections of the extract 150 mg/kg for 12 days. On days 5 and 12, the extract-treated ob/ob mice had significantly lower fasting blood glucose levels compared to day 0 (both p < 0.05). Glucose tolerance improved significantly, which was shown by overall glucose excursion, calculated as area under the curve (AUC) during the two-hour IP glucose tolerance test. The AUC decreased by 31.8% on day 12 compared to day 0 (p < 0.01). In addition, after 12 days of the berry extract treatment, a significant reduction in body weight (p < 0.01 compared to day 0) and a significant increase in body temperature (p < 0.01 compared to day 0) was noticeable. Our results support in vivo antihyperglycemic and antiobese activity of American ginseng berry extract that may prove to be of clinical importance in the prevention and treatment of Type 2 diabetes.

Antihyperglycemic effects of total ginsenosides from leaves and stem of Panax ginseng.

AbstractAim:The antihyperglycemic effects of the total ginsenosides in Chinese ginseng (TGCG), extracted from leaves and the stem, were evaluated in diabetic C57BL/6J ob/ob mice.Methods:Animals received daily intraperitoneal injections of TGCG (100 and 200 mg/kg) or oral administration (150 and 300 mg/kg) for 12 d. Fasting blood glucose levels and body weight were measured after fasting the animals for 4 h. Peripheral glucose use was also measured using an intraperitoneal glucose tolerance test.Results:In the injection group, a high dose of TGCG (200 mg/kg) significantly lowered the fasting blood glucose levels in ob/ob mice on d 12 (153 ± 16 mg/dL vs 203±9.8 mg/dL, P<0.01, compared to vehicle-treated group). In the oral group, blood glucose decreased notably with a dose of TGCG (300 mg/kg) on d 12 (169.1±12.6 mg/dL vs 211.6±13.8 mg/dL, P<0.05, compared to the vehicle-treated group). Glucose tolerance was also improved markedly in ob/ob mice. Furthermore, a significant reduction in bodyweight (P<0.05) was observed after 12 d of TGCG (300 mg/kg) treatment in mice from the oral group.Conclusion:The results indicated that in a diabetic ob/ob mouse model TGCG was endowed with significant anti-hyperglycemic and anti-obesity properties. Therefore, the total ginsenosides extracted from Chinese ginseng leaves and the stem may have some potential for treating diabetes.

Anti-diabetic effects of Gymnema yunnanense extract

In this study, we evaluated anti-hyperglycemic effect and body weight reduction activity of Gymnema yunnanense extract in obese ob/ob and diabetic db/db mice. Animals received daily intraperitoneal injections of the extract 100 mg/kg for 12 days. On Day 5, the extract-treated ob/ob mice had significantly lower fasting blood glucose levels compared to vehicle-treated mice (161+/-14.5mg/dl versus 238+/-21.5mg/dl, P<0.01). On Day 12, the extract-treated ob/ob mice had normal fasting blood glucose levels, compared with vehicle-treated mice (119+/-3.3mg/dl versus 240+/-12.9 mg/dl, P<0.01). Glucose tolerance improved significantly. This was demonstrated by overall glucose excursion calculated as area under the curve (AUC) during the 2h intraperitoneal glucose tolerance test (IPGTT), which decreased by approximately 22% (P<0.01) compared to vehicle-treated ob/ob mice. In addition, extract-treated ob/ob mice lost weight significantly from 51.7+/-1.9 g on Day 0 to 45.7+/-1.2g on Day 12 (P<0.05 compared to vehicle-treated mice). In db/db mice, after treatment with same dose of the extract, fasting blood glucose levels also decreased significantly from Day 0 of 247+/-13.9 mg/dl to Day 5 of 172+/-7.5mg/dl and to Day 12 of 190+/-2.7 mg/dl (both P<0.01 compared to vehicle-treated group from Day 0 of 239+/-12.1mg/dl to Day 5 of 230+/-8.5mg/dl and Day 12 of 247+/-18.9 mg/dl, respectively). After 12 days of extract treatment, body weight in db/db mice reduced from 61.8+/-1.4 g on Day 0 to 59.8+/-1.1g on Day 12 (P<0.05). Our results support an in vivo anti-hyperglycemic and body weight reduction activity of G. yunnanense extract that may prove to be of clinical importance in improving the management of type 2 diabetes.

Anti-hyperglycemic effect of the polysaccharides fraction from American ginseng berry extract in ob/ob mice

In this study, we evaluated the anti-hyperglycemic effect of a polysaccharides fraction from American ginseng berry extract in diabetic ob/ob mice. All animals received daily intraperitoneal injections of polysaccharides at 150 mg/kg body wt. (n = 5), polysaccharides at 50 mg/kg body wt. (n = 5), or vehicle (n = 5) for 10 consecutive days. On Day 5, as compared to the vehicle-treated mice (230.5 +/- 13.5 mg/dl, mean +/- S.E), mice from both treated groups showed significantly lower fasting blood glucose levels (187.4 +/- 20.5 mg/dl and 187.4 +/- 17.1 mg/dl), respectively (both P < 0.05). On Day 10, compared to the vehicle group (240.1 +/- 12.3 mg/dl), the 50 mg/kg dose group were at 188.4 +/- 12.6 mg/dl (P < 0.05), and the 150 mg/kg dose group were normoglycemic (148.8 +/- 17.6 mg/dl, P < 0.01). Those ob/ob mice treated with vehicle did not, however, show significant changes in fasting blood glucose levels. Data from the intraperitoneal glucose tolerance test (IPGTT) showed that, compared to Day 0, there was a significant improvement in glucose tolerance in animals who received the 50 and 150 mg/kg polysaccharide doses, and the area under the curve (AUC) decreased 15.5% (P < 0.05) and 28.2% (P < 0.01), respectively. Interestingly, after cessation of polysaccharide treatment, the fasting blood glucose levels stayed lower, and returned to control concentration on Day 30. We also observed that the polysaccharides fraction did not affect body weight changes in ob/ob mice. Our data suggest that the polysaccharides fraction from American ginseng berry extract has a potential clinical utility in treating diabetic patients.

Leptin Reduces Body Weight Gain in Neonatal Rats

Leptin (OB protein) elicits a neuroendocrine response to starvation and states of nutritional abundance to stabilize the proportion of body fat. Leptin has dramatic effects on food intake and energy expenditure in adult and juvenile rodents. However, whether the neonatal period is associated with the development of an effective leptin feedback system is still not known. In this study, we evaluated the effects of peripherally administered leptin on body weight changes in neonatal rats during the early suckling period (from birth to 10 d). Our results show that daily i.p. injections of leptin (0.3 μg/g and 1.0 μg/g) to neonatal rats led to a significant reduction in weight gain over 10 d compared with the control group (p < 0.01 and p < 0.01, respectively). Concomitant with a reduction in weight gain, retroperitoneal fat pad weight also significantly decreased in the leptin-treated group. Our data indicate that the potential for energy balance regulation by leptin occurs in the first day after birth. In addition, we also observed that 3 d after discontinuing leptin treatment, the body weight as well as the fat pad weight of leptin-treated pups returned to the control level. Our results demonstrate that leptin reduces body weight gain in neonatal rats.Committee on Clinical Pharmacology [C.-S.Y.] and Department of Anesthesia and Critical Care [A.S.A., L.Z., J.P.L., J.-T.X.], The Pritzker School of Medicine, The University of Chicago, Chicago, Illinois 60637, U.S.A.; and Department of Pharmacology, Amgen, Thousand Oaks, California 91320, U.S.A. [Z.Q.S.]

Curry Leaf (Murraya koenigii Spreng.) Reduces Blood Cholesterol and Glucose Levels in ob/ob Mice

We observed that curry leaf (Murraya koenigii) extract possesses the property to decrease blood cholesterol and blood glucose levels in diabetic ob/ob mice. Mice received daily intraperitoneal injections of 80 mg/kg curry leaf extract for 10 consecutive days. The extract significantly decreased blood cholesterol level from 277.6 +/- 16.6 mg/d (day 0) to 182.0 +/- 15.3 mg/d (day 10, p < 0.01 compared with the change in vehicle group). The extract also significantly decreased blood glucose level from 387.0 +/- 15.6 mg/dl (day 0) to 214.0 +/- 26.6 mg/dl (day 10, p < 0.01). In addition, body weight was reduced after extract treatment. Our data suggest that curry leaf may be proved to be of clinical importance in improving the management of high cholesterol level and type 2 diabetes.

Effects of Panax quinquefolius L. on brainstem neuronal activities: Comparison between Wisconsin-cultivated and Illinois-cultivated roots

Brainstem neurons receiving subdiaphragmatic vagal inputs were recorded in an in vitro neonatal rat brainstem-gastric preparation. Aqueous extracts of American ginseng root (Panax quinquefolius L.) from Wisconsin and Illinois were applied to the gastric compartment or the brainstem compartment of the bath chamber to evaluate the peripheral gut or central brain effects of the extracts on brainstem unitary activity. After P. quinquefolius extract application to the gastric or brainstem compartment, a concentration-related inhibition in neuronal discharge frequency in brainstem unitary activity was observed, suggesting that P. quinquefolius plays an important role in regulating the digestive process and modulating the brain function in the rat. In this study, pharmacological effects of Wisconsin-cultivated P. quinquefolius and Illinois-cultivated P. quinquefolius were compared. Our results showed that Illinois-cultivated P. quinquefolius possesses a significantly stronger peripheral gastric as well as central brain modulating effect on brainstem neuronal activity. Data from our high performance liquid chromatography ginsenoside analysis suggest that this increase in inhibitory effects by Illinois-cultivated P. quinquefolius may be due to its different ginsenoside profile.