Effect of the leaves aqueous extract of Jodina rhombifolia (Hook. & Arn.) Reissek (Santalaceae) on intestinal function and its acute toxicity

Ethnopharmacological relevance: In Argentine traditional medicine it is recorded the use of Jodina rhombifolia (Hook. & Arn.) Reissek (Santalaceae) leaves for treating various affections that compromise the intestinal normal functioning.

Aim of the study: The aim of this study was to assess the effect of J. rhombifolia leaves lyophilized aqueous extract on the intestinal function by means of in vivo and ex vivo experimental assays for determinate the antidiarrheal and antispasmodic capacity. Furthermore, was to evaluate its acute toxicity potential by oral and intraperitoneal administration of extract.

Materials and methods: The in vivo assays were conducted by the experimental techniques of intestinal transit in mice, intestinal fluid accumulation in rats and Castor oil-induced diarrhea in mice. In the ex vivo assays, isolated rat duodenum and ileum segments were used for to evaluate the antispasmodic activity through contractile concentration-response curves induced by Carbachol and CaCl₂. The acute toxicity of the extract was also investigated by oral and intraperitoneal administration.

Results: The extract intraperitoneal administration at the doses 125, 250 and 500 mg/kg, caused a marked reduction in the normal intestinal transit and in the number of diarrheal episodes in a dose-dependent manner. However, the extract did not produce significant changes in the intestinal fluid accumulation with any of the tested dose. The extract demonstrated a non-competitive inhibitory effect on the contractions of intestinal smooth muscle experimentally provoked by the spasmogenic agents Carbachol and CaCl2 in a dose-dependent manner (IC₅₀ = 10.57 ± 1.38 and 6.29 ± 1.54 mg extract/ml Tyrode solution in the isolated organ bath, respectively). ANOVA indicated a significative effect of treatment (p<0.001).

Conclusions: The scientific evidence achieved based in the used experimental models allows us to indicate that J. rhombifolia leaves lyophilized aqueous extract manifest an antispasmodic activity on intestinal smooth muscle without observation of apparent toxicity symptoms.

Keywords: Acute toxicity; Jodina rhombifolia; effect on the intestinal function; leaves aqueous extract.