Role of selected Indian plants in management of type 2 diabetes

Department of Medicine, All India Institute of Medical Sciences, New Delhi, India. abhasaxena2000@yahoo.com

Type 2 diabetes has become a global epidemic. Modern medicines, despite offering a variety of effective treatment options, can have several adverse effects. Ayurveda, a science that uses herbal medicines extensively, originated in India. Of considerable interest is the adoption of Ayurveda by the mainstream medical system in some European countries (e.g., Hungary), emphasizing this modality is increasing worldwide recognition. From ancient times, some of these herbal preparations have been used in the treatment of diabetes. This paper reviews the accumulated literature for 10 Indian herbs that have antidiabetic activity and that have been scientifically tested. Few of these herbs, such as Momordica charantia, Pterocarpus marsupium, and Trigonella foenum greacum, have been reported to be beneficial for treating type 2 diabetes. Mechanisms such as the stimulating or regenerating effect on beta cells or extrapancreatic effects are proposed for the hypoglycemic action of these herbs.

Antihyperglycaemic and antioxidant effect of hyponidd, an ayurvedic herbomineral formulation in streptozotocin-induced diabetic rats

Department of Biochemistry, Annamalai University, Annamalai Nagar-608 002, Tamil Nadu, India

Hyponidd is a herbomineral formulation composed of the extracts of ten medicinal plants ( Momordica charantia, Melia azadirachta, Pterocarpus marsupium, Tinospora cordifolia , Gymnema sylvestre, Enicostemma littorale, Emblica officinalis, Eugenia jambolana, Cassia auriculata and Curcuma longa). We have investigated hyponidd for its possible antihyperglycaemic and antioxidant effect in diabetic rats. Rats were rendered diabetic by streptozotocin (STZ) (45 mg kg(-1) body weight). Oral administration of hyponidd (100 mg kg(-1) and 200 mg kg(-1)) for 45 days resulted in significant lowered levels of blood glucose and significant increased levels of hepatic glycogen and total haemoglobin. An oral glucose tolerance test was also performed in experimental diabetic rats in which there was a significant improvement in blood glucose tolerance in the rats treated with hyponidd. Hyponidd administration also decreased levels of glycosylated haemoglobin, plasma thiobarbituric acid reactive substances, hydroperoxides, ceruloplasmin and alpha-tocopherol in diabetic rats. Plasma reduced glutathione and vitamin C were significantly elevated by oral administration of hyponidd. The effect of hyponidd at a dose of 200 mg kg(-1) was more effective than glibenclamide (600 microg kg(-1)) in restoring the values to near normal. The results showed that hyponidd exhibits antihyperglycaemic and antioxidant activity in STZ-induced diabetic rats.

Pterocarpus marsupium and Trigonella foenum-graecum

To study the anti-cataract activity in alloxan diabetic rats

Journal of Ethnopharmacology 2004; 93:289-294

Anti-cataract activity of Pterocarpus marsupium bark and Trigonella foenum-graecum seeds extract in alloxan diabetic rats

V. Vats^a, S.P. Yadav^a, N.R. Biswas^b, J.K. Grover^a,

^aDepartment of Pharmacology, All India Institute of Medical Sciences, 4th Floor, Teaching Block, Ansari Nagar, New Delhi 110029, India ^bDepartment of Ocular Pharmacology, Dr Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India

Long-term complications are frequently encountered in diabetes mellitus and are difficult to treat. This study was undertaken to assess the effect of three antidiabetic plants on the development of cataract in rats. An aqueous extract of Pterocarpus marsupium Linn bark (PM, Hindi name: Vijaysar) (1 g kg-1 day-1), Ocimum sanctum Linn leaves (OS, Hindi name, Tulsi) (200 mg kg-1 day-1) and alcoholic extract of Trigonella foenum-graecum Linn seeds (FG, Hindi name, Methi) (2 g kg-1 day-1) were given to alloxan (120 mg kg-1) diabetic rats until the development of cataract. Serum glucose and body weight were monitored at regular intervals while cataract was examined through naked eye as well as slit lamp at 75, 100 and 115 days after alloxan administration. Administration of all the three plant extracts exerted a favorable effect on body weight and blood glucose, the effects were best with PM followed by FG and OS. On the course of cataract development, PM followed by FG exerted anti-cataract effect evident from decreased opacity index while OS failed to produce any anti-cataract effect in spite of significant antihyperglycemic activity. 

Pterocarpus marsupium

Whole plant

Journal of Ethnopharmacology  2005; 97:253–260

Upregulation of Glut-4 and PPARg by an isoflavone from Pterocarpus marsupium on L6 myotubes: a possible mechanism of action

R. Anandharajan, K. Pathmanathan, N.P. Shankernarayanan, Ram A. Vishwakarma, Arun Balakrishnan

Centre For Biotechnology, Anna University, Chennai 600025, Tamil Nadu, India, Bio-organic Chemistry Laboratory, National Institute of Immunology, JNU complex, New Delhi 110 067, India. V.H.S Leprosy project, Shakthi Nagar, Erode 638315, Tamil Nadu, India

The purpose of the present study is to analyse the influence of Pterocarpus marsupium methanolic extract and isolated Pterocarpus  marsupium isoflavone on a battery of cellular targets Glut-4, PPAR
and PI3 kinase. Pterocarpus marsupium is an anti-diabetic plant indigenous to South India. Sequential extraction performed with different solvents were analysed for glucose uptake activity at each step. Fraction-9 showing maximum glucose activity on glucose uptake was purified by column chromatography and the structure was elucidated as 7-O--l-rhamnopyranosyl oxy-4-methoxy-5-hydroxy isoflavone using NMR and mass spectroscopy. The significant glucose uptake showed by Pterocarpus marsupium crude and pure was comparable with insulin and rosiglitazone. Elevation of Glut-4 and PPARg gene expression in parallel with glucose uptake supported the in vitro glucose uptake activity of Pterocarpus marsupium methanolic extract and Pterocarpus marsupium isoflavone. The inhibitory effect of cycloheximide on Pterocarpus marsupium methanolic extract and Pterocarpus marsupium isoflavone-mediated glucose uptake suggested that new protein synthesis is required for elevated Glut-4 protein expression. PI3 kinase plays an important role in glucose transport and activated by Pterocarpus marsupium methanolic extract but not the isolated pure isoflavone. Therefore, we postulate that the isoflavone from Pterocarpus marsupium may activate glucose transport by a PI3 kinase independent pathway, which require further analysis. 

In our experiments 30 hypoglycaemic medicinal plants (known and less known) have been selected for thorough studies from indigenous folk medicines, Ayurvedic, Unani and Siddha systems of medicines. In all the experiments with different herbal samples (vacuum dried 95% ethanolic extracts), definite blood glucose lowering effect within 2 weeks have been confirmed in alloxan diabetic albino rats. Blood glucose values are brought down close to normal fasting level using herbal samples at a dose of 250 mg/kg once, twice or thrice daily, as needed. While evaluating comparative hypoglycaemic activity of the experimental herbal samples, significant blood glucose lowering activities are observed in decreasing order in the following 24 samples-Coccinia indica, Tragia involucrata, G. sylvestre, Pterocarpus marsupium, T. foenum-graecum, Moringa oleifera, Eugenia jambolana, Tinospora cordifolia, Swertia chirayita, Momordica charantia, Ficus glomerata, Ficus benghalensis, Vinca rosea, Premna integrifolia, Mucuna prurita, Terminalia bellirica, Sesbenia aegyptiaca, Azadirachta indica, Dendrocalamus hamiltonii, Zingiber officinale, Aegle marmelos, Cinnamomum tamala, Trichosanthes cucumerina and Ocimum sanctum. Present studies besides confirming hypoglycaemic activities of the experimental herbal samples, help identify more potent indigenous hypoglycaemic herbs (in crude ethanolic extract) from the comparative study of the reported experimental results.