Synergic actions of polyphenols and cyanogens of peanut seed coat (Arachis hypogaea) on cytological, biochemical and functional changes in thyroid.

In animals, long-term feeding with peanut (Arachis hypogaea) seed coats causes hypertrophy and hyperplasia of the thyroid gland. However, to date there have been no detailed studies. Here, we explored the thyroidal effects of dietary peanut seed coats (PSC) in rats. The PSC has high levels of pro-goitrogenic substances including phenolic and other cyanogenic constituents. The PSC was mixed with a standard diet and fed to rats for 30 and 60 days, respectively. Animals fed with the PSC-supplemented diet showed a significant increase in urinary excretion of thiocyanate and iodine, thyroid enlargement, and hypertrophy and/or hyperplasia of thyroid follicles. In addition, there was inhibition of thyroid peroxidase (TPO) activity, 5’-deiodinase-I (DIO1) activity, and (Na+-K+)-ATPase activity in the experimental groups of rats as compared to controls. Furthermore, the PSC fed animals exhibited decreased serum circulating total T4 and T3 levels, severe in the group treated for longer duration. These data indicate that PSC could be a novel disruptor of thyroid function, due to synergistic actions of phenolic as well as cyanogenic constituents.

Clinical and biochemical features of malnutrition related diabetes mellitus

The aims of this study were to characterize clinically and biochemically malnutrition related diabetes mellitus (MRDM) as it presents in Jamaica (J-type or phasic insulin dependent diabetes mellitus) and to examine the food toxin (linamarin)/malnutrition hypothesis as a possible aetiological factor in the onset of MRDM. The study was broadly divided into two major areas: (i) Clinical or patient study and (ii) Animal model study. The patient population consisted of thirty-four, (23 females, 17 males) who attend the Diabetic Outpatient Clinic of the University Hospital of the West Indies. This group consisted of 14 phasic insulin dependent diabetes mellitus (PIDDM) (8 females, 6 males) 10 non-insulin dependent diabetes mellitus (IDDM), (6 females, 4 males). Ten (10) normal (4 females, 6 males) subjects also participated. The diabetic and normal subjects were matched for age, body mass index and duration of diabetes (among diabetics). Comparitive studies were performed on insulin receptor binding, hormonal profile, glucose tolerance, blood status, renal, hepatic and pancreatic function. The results show a significantly decreased white and red blood cell binding to insulin (P<0.05), extensive kidney damage (P<0.05) and increased pancreatic echogenicity in PIDDM. These findings support a separate identity of the latter syndrome from Types 1 and 11 diabetes mellitus. In the animal model study, the dogs (male and female) were maintained on a diet of cornmeal cooked with chicken, fortified with Purina laboratory chow and water ad libitum. Malnutrition was induced by restricting the diet to a very small quantity of cornmeal only for a period of 7-10 days. The recovered dogs were re-fed the normal diet with added milk and multi-vitamin supplement. Linamarin dosage of 20 mg per kg body weight induced abnormally high glucose levels, and in two cases the hyperglycaemia was sustained for several days. There was an associated decrease in binding of insulin to erythrocytes and mononuclear leucocytes, as well as prevailng hypoinsulinaemia in the limarin-induced hyperglycaemic conditions. This animal study presents a possible aetiological model for malnutrition related diabetes mellitus (Summary)