SCREENING OF INDIGENOUS MEDICINAL PLANTS IN NORMAL AND ALLOXAN DIABETIC RABBITS FOR ANTIDIABETIC ACTIVITY

Abstract

The study was purposefully designed to investigate the hypoglycaemic effects of the indigenous medicinal plants Cassia sophera, Caralluma tuberculata and Achillea santolina allegedly used in etlmomedicine for the remedy of diabetes mellitus since time immemorial in India and Pakistan. First four experiments were designed to find out the hypoglycaemic effects of Cassia sophera powdered seeds. Effects of powdered seeds on blood glucose levels in normal non-diabetic rabbits were carried out in increasing doses i.e. 2, 3, 4g/kg body weight at 0, 2, 4, 8, 12 and 24 hours intervals. It was found that there was no significant decrease at 4 hours interval with 2g/kg body weight but significant decrease occurred at 8 and 12 hours intervals, while highly significant decrease in mean blood glucose level were observed at 4, 8 and 12 hours with both 3g/kg and 4g/kg body weight. The effects of methanolic and aqueous extracts equivalent to 4g/kg body weigllt of Cassia sophera powdered seeds were also studied in normal rabbits which showed significant decrease (p<O.05) at 8 hours and 12 hours intervals. However, the methanolic extract of Cassia sophera seeds produced better hypoglycaemia as compared to aqueous extract. The effects of these extracts were comparable to Acetohexamide one of the oral hypoglycaemic agent. The same study was also done in alloxan-induced diabetic rabbits and it was noticed that increasing doses 2, 3 and 4g/kg body weight of Cassia sophera powdered seeds caused significant decrease in blood glucose level and highly significant decrease (p<O.OO 1) in blood glucose level was noticed with methanolic extracts at 4 hours interval which continue up to 8 hours while treatment with aqueous extract with Cassia sophera seeds showed highly significant decrease at 12 hours time. It seems that powdered seeds of Cassia sophera contained more than one type of hypoglycaemic principles, which have exerted a significant and consistent hypoglycaemic effects in normal as well as in diabetic rabbits. No change in the normal behavioral pattern in the treated animals or toxic adverse effects were observed during the study. The next four experiments were designed to study the hypog/ycaemic effects of both Caralluma tuberculata and Achillea santolina, which are also used as traditional 1 Abstract medicine for treating diabetes mellitus in this subcontinent. The study was designed to investigate the hypoglycaemic effects of these medicinal plants together. The experiments were carried out with crude extract and carbon tetrachloride (CCI4) fractions in capsule and cooking oil forms of both plants and compared in different dosage forms. In the first experiment, the crude extract 200mg/kg body weight of Carallwna tuberculata and Achillea santolina showed highly significant decrease (p<O.OOl) in mean blood glucose level at 2, 4, 8 and 12 hours. But these Caralluma tuberculata vs Achillea santolina showed highly significant (p<O.OOl) difference at 2, 4, 8 and 12 hours times. The metformin 500mg/kg body weight was also given to compare its effects with the plant crude extracts, which was more or less intermediate between that of crude extracts of Caralluma tuberculata and Achillea santolina. Both crude extracts of both plants caused highly significant decrease (p<O.OOl) in blood glucose levels in diabetic rabbits. It was also noticed that Metformin (glucophage) appears to be less effective compare to that with Caralluma tuberculata and Achillea santolina. The diabetic rabbits were treated with carbon tetrachloride (CCI4) fractions 100l1lg/kg body weight of Caralluma tuberculata and Achillea santolina in capsule form, blood glucose level dropped markedly at 2 hours and fmiher more at 4 hours. These effects were compared with Metformin, which showed that Achillea santolina produces significantly low blood glucose level quite late as compared to Metformin. The diabetic rabbits were also treated with carbon tetrachloride (CC14) fractions 100mg/kg body weight of both Caralluma tuberculata and Achillea santolina in cooking oil. Highly significant decrease (p<O.OOl) in blood glucose levels occmTed in 2, 4, 8 and 12 hours intervals. However, it showed that Caralluma tuberculata administered in cooking oil leads to higher reduction in blood glucose level than that administered in capsule form. It is therefore, concluded that Caralluma tuberculata is one of the better hypoglycaemic agent to be used as herbal medicine for the treatment of diabetes mellitus. It is also known well for its vegetables usages since centuries, causing no apparent adverse effects.