Identification of toxic fractions of Mimosa invisa (Anathottavadi) and its toxicity in rabbits

Abstract

The present study was undertaken to identify the toxic fraction of Mimosa invisa in rabbits and to assess to toxicity of Mimosa invisa fresh juice, cold alcoholic extract and various fractions of alcoholic extract utilizing rabbit as a model along with treatment study. The experiment was conducted in two phases. The first part of the study involved assessment of toxicity of fresh juice of Mimosa invisa (group II) and cold alcoholic extract (group Ill). Group I served as control. The preliminary tests were conducted to derive the toxic dose of fresh juice and alcoholic extract of Mimosa invisa. The toxic doses were 25 g/kg and 1 g/kg body weight for Mimosa invisa fresh juice and alcoholic extract respectively. The clinical symptoms, biochemical parameters and haemogram were observed to assess the toxicity. The serum ALT, AST and GGT levels showed significant increase in both the groups. The serum creatine kinase levels exhibited an increase followed by a decrease. There was a significant increase in serum creatinine and urea levels. There were no changes in serum total protein, albumin, globulin and albumin-globulin ratio. Significant decrease in VPRC, haemoglobin and RBC count could be noticed. The erythrocyte indices did not show any variations. The leucocytosis was observed in group II and III when compared to control (group I). Lymphocytosis with neutropenia were also observed in both the groups. The second phase of the study involved identification of toxic dose of each fraction of Mimosa invisa: The preliminary studies revealed that chloroform fraction (Fraction I) and water insoluble residue (fraction IV) were not toxic to rabbits while the fraction II (n-butanol fraction) and fraction III (aqueous fraction) were toxic to rabbits. Hence the two toxic fractions were pooled and used for further studies. It was found that 0.4 g/kg of pooled toxic fraction was toxic in rabbits. The toxicity was assessed by the evaluation of clinical symptoms, biochemical parameters and haemogram. The group V (pooled toxic fraction) showed inappetence, dullness, lethargy and reluctant to move. A significant increase in serum ALT, AST and GGT levels were observed. The serum ALP levels showed an increase followed by a decrease. The serum creatine kinase also showed similar increase followed by decrease. The creatinine and urea levels exhibited a continuous increase in group V. There were no changes in total protein, albumin, globulin and albumin-globulin ratio. The VPRC, RBC and haemoglobin showed significant decrease but there were no changes in erythrocyte indices. A significant leucocytosis was observed in group V. The differential leucocyte count showed lymphocytosis with neutropenia. The group VI (Half the toxic dose of pooled toxic fraction) failed to produce toxicity as evidenced by biochemical parameters and haemogram. The group VII (Double the toxic dose of pooled toxic fraction), all the animals died within 12-24 hours of administration of the dose. The group VIII animals were treated with a decoction prepared from equal quantities of Boerhvia diffusa, Hygrophila auriculata and Tribulus terrestris along with pooled toxic fraction of Mimosa invisa. The prominent symptom of inappetence was only for a short period of time (1-2 day). Then the animals started taking normal feed and water. The serum AL T, AST and GGT levels were significantly increased during the first five days, then the values returned to normal level. The serum creatine kinase and ALP levels did not show significant changes. The serum creatinine and urea levels showed significant increase followed by decrease. All the parameters showed significant improvement when compared with group V (pooled toxic fraction alone). There were no changes in serum protein, 'albumin, globulin and albumin-globulin ratio. The screening of alcoholic extract and various fractions revealed that the alcoholic extract n-butanol fraction and aqueous fraction contained steroids phenolic compounds, tannins, flavonoids, glycosides, diterpenes triterpenes and saponins. The chloroform fraction was positive for flavonoids only, whereas water insoluble fraction contained flavonoids and traces of tannins, triterpenes and saponins. From the results of the present study, it is concluded that the phytotoxin present in M invisa is nephrotoxic and hepatotoxic. The treatment schedule tried using a decoction of Boerhavia diffusa, Tribulus terrestris and Hygrophila auriculata could protect kidney and liver from the phytotoxin present in M invisa. Further study is needed to isolate the phytotoxin present in M invisa so that a specific antidote can be developed.