Studies on the efficacy and mechanism of action of traditional plant treatments for diabetes mellitus

Abstract

Although several hundred traditional plant treatments for diabetes mellitus have been described few have received scientific and medical scrutiny. The aim of this study was to investigate the efficacy and mechanism of action of Agaricus campestris ( edible mushroom), Agrimony eupatoria (agrimony), Coriandrum sativum (coriander), Eucalyptus globulus (eucalyptus), Juniperus communis (juniper), Medicago saliva (alfalfa), Sambucus nigra (elder) and Viscum album (mistletoe).

Administration of Agaricus campestris, Agrimony eupatoria, Coriandrum sativum, Eucalyptus globulus and Medicago saliva to lean mice countered the hyperglycaemia induced by streptozotocin. Juniperus communis failed to ameliorate the diabetes of streptozotocin-induced diabetic mice and exacerbated symptoms of polydipsia. No plant investigated had anti-hyperglycaemic effects in obese hyperglycaemic ( oblob) mice.

The effects of aqueous plant extracts on glucose uptake and metabolism were investigated using isolated mouse abdominal muscle. Aqueous extracts of Agaricus campestris, Agrimony eupatoria, Coriandrum sativum, Eucalyptus globulus, Medicago sativa and Sambucus nigra enhanced glucose uptake, glucose oxidation and glycogenesis in the absence of added insulin.

The effect of aqueous plant extracts on insulin secretion was investigated using the clonal BRIN-BDll pancreatic B-cell line. Aqueous extracts of Agaricus campestris, Agrimony eupatoria, Coriandrum sativum, Eucalyptus globulus, Medicago sativa, Sambucus nigra and Viscum album exhibited dose-dependent stimulatory effects on insulin secretion in the presence of low glucose. Specific actions on the insulin secretory pathway differed. The characteristics of the insulin stimulating component( s) of plant extracts ( effect of prolonged heat, dialysis, altered pH and acetone treatments) were investigated but no consistent characteristic was established. Aqueous extract of Juniperus communis did not effect insulin secretion.

There is a need for new drugs that target the underlying metabolic lesions associated with diabetes mellitus. The present study demonstrates the antihyperglycaemic effects of a number of traditional plant treatments for diabetes mellitus together with their ability to achieve extra pancreatic and pancreatic actions. The ability of a number of aqueous plant extracts (namely Agaricus campestris, Agrimony eupatoria, Coriandrum sativum, Eucalyptus globulus, Medicago sativa and Sambucus nigra) to exert both extra pancreatic and pancreatic actions serves to further highlight the important role traditional plant treatments have to play in developing the future repertoire of therapeutic strategies for diabetes mellitus.

Date of Award	Apr 1996
Original language	English
Awarding Institution	Ulster Univeristy
Supervisor	Peter Flatt (Supervisor)