Long-term hepatotoxicity and hypoglycaemic study of Aqueous extracts of Carica papaya leaves on normal rabbits

The use of Carica papaya extracts as an anti-diabetic remedy in Nigeria is well documented. Since these extracts are usually taken for long periods of time, it is important to assess their long term biochemical effects so as toascertain their safety. In this study, the effects of aqueous extracts of C. papaya leaves, orally administered daily at 200mg/Kg body weight, on body weight, blood glucose and liver function tests of normal rabbits were observed at preset times in the serum for 24 weeks, and in the tissues. Administration of C. papaya aqueous leave extracts caused significant (p<0.05) reductions in body weight and fasting blood glucose levels for the 24 weeks of monitoring. The parameters used to assess liver function (alanine transaminase [ALT], aspartate transaminase [AST], alkalinephosphatase [ALP], gamma glutamyl transferase [ã-GT], total and direct bilirubin) revealed that the administration of C. papaya extracts caused an initial toxic response from the liver, as well as, bile duct obstruction, that were transient and not severe. Since the hypoglycaemic effects of C. papaya was again established by this study, further studies to harness the therapeutic effects and reduce the negative side effects are required; long term consumption of the extracts should be closely monitored by a physician

Long-term effects of three hypoglycaemic plants (Irvingia gabonensis, Urena lobata and Carica papaya) on the oxidative status of normal rabbits

Medicinal plants have been recognized to have therapeutic effects and they may also have toxic side effects. Our previous studies have shown that Irvingia gabonensis, Urena lobata and Carica papaya, locally used in Nigeria to treat diabetes, possess long term hypoglycaemic and anti-obesity effects on normal rabbits. In this study, the long term effects of aqueous extracts of I. gabonensis bark, U. lobata root and C. papaya leaves on the oxidative status of normal rabbits were monitored at specific intervals in the serum for 24 weeks, and in the tissues. Oxidative status was determined by measuring activities of superoxide dismutase (SOD) and catalase (CAT), and the concentration of malondialdehyde (MDA). Significant (p<0.05) decreases were observed in some weeks in the serum MDA levels; also, liver and pancreatic MDA levels were significantly (p<0.05) lower for all treated rabbits. SOD and catalase activities in the serum and tissue of the rabbits treated with the medicinal plants were generally higher or statistical similar to control. Findings in this study showed that these hypoglycemic medicinal plants did not exert oxidative damage; in some instances, particularly in the pancreas, they were found to be protective against oxidative damage. KEYWORDS: Medicinal plants, Irvingia gabonensis, Urena lobata, Carica papaya, Hypoglycaemic plants, oxidative damag

Liver function of Streptozotocin- Induced Diabetic Rats Orally Administered Aqueous Root-Bark Extracts of Tetrapleura tetraptera (Taub).

The aqueous root-bark extract of Tetrapleura tetraptera Taub. has been shown to  ameliorate streptozotocin (STZ)-induced hyperglycaemia and dyslipidaemia. This study evaluated the liver status of STZ- induced diabetic rats treated with aqueous root-bark extract of T. tetraptera for 35 days. Twenty-four (24) rats in four groups (normal control, diabetic control, T. tetraptera treated STZ induced diabetic rats at 150 mg/kg b. w. and T. tetraptera treated STZ-diabetic rats at 300 mg/kg b. w.) were used. Serum and liver alanine and aspartate transaminases (ALT and AST), alkaline phosphatase (ALP), gamma glutamyl transferase (γGT) activities and protein concentration were assessed. Also, serum albumins, globulins, total and direct bilirubin concentrations were measured. STZ induced diabetes significantly (P<0.05) increased serum ALT, AST and ALP activities, while treatment of diabetic rats with T. tetraptera reduced the activities of these enzymes. T. tetraptera caused significant (P<0.05) increases in serum γGT, total and direct bilirubin levels, especially at the higher dose (300mg/kg body weight). While the treatment of STZ induced diabetic rats with the extract of T. tetraptera ameliorated hepatocellular damage, at the higher dose of 300mg/kg body weight, T. tetraptera treatment may cause bile duct obstruction. The use of this plant in the treatment of diabetes or other diseases should therefore be monitored with respect to hepato-biliary toxicity.Keywords: Tetrapleura tetraptera, STZ diabetes, Liver function, Toxicity, Medicinal plant

Immunostimulatory and Other Haematological Effects of Long Term Administration of Aqueous Leaf Extract of Carica Papaya Linn. (Caricaceae) Extracts to Normal Rabbits

Carica papaya Linn. (Caricaceae)is used traditionally to treat malaria, hypertension, sickle cell anemia and diabetes. Its long-term hypoglycaemic and anti-obesity effects in normal rabbits are documented. This study assessed the long term immunostimulatory and other haematological effects of aqueous C. papaya leaf extract administered orally to normal rabbits at 200 mg/kg body for 24 weeks at specific intervals (week 1, 2, 3, 4, 6, 8, 10, 12, 15, 18, 21 and 24). The total white blood cell (WBC) and neutrophil counts of treated rabbits were mostly slightly higher than control. Neutrophil count transiently significantly (p<0.05) decreased while lymphocyte count increased in week 6; monocyte (week4), basophil (week 4) and eosinophil (week 3) counts also briefly significantly (p<0.05) increased, suggesting an ephemeral negative immunological and allergic response of the rabbits to the administered extract. However, these events were not sustained as the values of these parameters subsequently returned to control levels. Red blood cell (RBC), packed cell volume (PCV) and haemoglobin (Hb) concentration of treated rabbits were slightly higher than control; the mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were mostly statistically similar to control, implying improvement in haematopoiesis. This study revealed that long term administration of C. papaya extract had immunostimulatory and haematopoietic effects on normal rabbitsKeywords: Carica papaya, Immunostimulatory, Haematological, Rabbits, Medicinal plant

Effect of aqueous root bark extract of Tetrapleura tetraptera (Taub) on blood glucose and lipid profile of streptozotocin diabetic rats

Background: Tetrapleura tetraptera (Schum. and Thonn) Taub is used in Africa as a spice and in folk medicine. Its documented biological activities include molluscicidal, hypotensive, anti-convulsant, anti-inflammatory, hypoglycaemic and anti-microbial effects.Objective: This study evaluated the potential role of the aqueous root-bark extract of T. tetraptera in the treatment of diabetes and its antihyperlipidemic effect in streptozotozin-induced diabetic rats.Methods: T. tetraptera extract was orally administered to streptozotocin (STZ) diabetic rats at 150 and 300mg/kg body weight (Groups 3 and 4). The effect of the extract on body weight, fasting blood sugar (FBS) and serum lipid profile of the treated diabetic rats were compared with untreated control rats (Group 1) and untreated diabetic control rats (Group 2) after 35 days of treatment.Results: T. tetraptera treatment caused a non-significant improvement of STZ-induced weight loss and significantly (p<0.05) reduced FBS in treated diabetic rats. Serum triacylglycerol, total cholesterol and LDL-cholesterol concentration significantly (p<0.05) reduced in treated diabetic rats while the HDL- cholesterol concentration of the 150mg/kg body weight treated group increased.Conclusion: The antidiabetic effect of the aqueous root bark extract of T. tetraptera validates the folkloric use of this part of the plant as an antidiabetic remedy. The associated anti-hyperlipidaemic effect may be useful in the treatment of chronic diabetic complications.Keywords: Tetrapleura tetraptera, diabetes, Antidiabetic, Antihyperlipidemic, Rat