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Studies were conducted to investigate a possible haemolytic effect on rat erythrocytes and spasmolytic activity on rat aorta and guineapig ileum of a methanol extract obtained from roots of Solanum asterophorum (Sast-MeOHR). A sample of blood was collected from fasting Wistar male rats to obtain erythrocyte suspensions. Sast-MeOHR was added to the suspensions at various concentrations and in different preparations and the percentage of haemolysis was calculated. The spasmolytic activity of the Sast-MeOHR extract was also determined on rat aorta and guineapig ileum by relaxation, expressed as reversal percentage of the initial contraction elicited by KCl. Results showed that the extract inhibited the tonic contractions in the guineapig ileum, suggesting that the blockade of calcium influx was through voltage-activated calcium channels, as these channels are responsible for maintaining this contractile response. The Sast-MeOHR extract caused no damage to the membrane of erythrocytes at concentrations that showed spasmolytic activity on guineapig ileum. Thus, it appeared that Sast-MeOHR probably had low or no in vivo toxicity.

Studies were conducted to determine the cytotoxicity of the total alkaloid fraction from root bark of Solanum paludosum (TAF-SP) on rat erythrocytes and investigate its possible spasmolytic effect on rat uterus and guineapig trachea. To determine the effect of the TAF-SP on rat erythrocytes, an erythrocyte suspension was obtained and TAF-SP was added at various concentrations and in different preparations and the haemolytic activity was evaluated. To evaluate the effect of TAF-SP on phasic contractions in rat uterus, the inhibition of response to submaximal carbachol or oxytocin was assessed by comparing the responses before and after addition of the extract. To assess the effect of the TAF-SP on contractions on guineapig trachea, relaxation was determined after the addition of TAF-SP. Results showed that TAF-SP had no significant cytotoxic effects on rat erythrocytes, but showed significant spasmolytic activity on rat uterus and guineapig trachea. In the rat uterus, this effect was more selective to carbachol, and in the guineapig trachea, the relaxant effect was potentiated in the absence of epithelium.

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Studies were conducted to determine the haemolytic activity of the methanol extract obtained from roots of Solanum asperum (SAr-MeOH) on rat erythrocytes and its spasmolytic activity on guineapig trachea and ileum. Blood samples were collected from rats through cardiac puncture to obtain erythrocyte suspensions for the evaluation of cytotoxic potential of SAr-MeOH by haemolysis. The relaxation of the guineapig trachea was determined by calculating the percentage of reverse carbachol-induced initial contraction after the addition of SAr-MeOH. Inhibition of response to submaximal carbachol in the guineapig ileum was assessed by comparing the responses before (control) and after addition of SAr-MeOH. Results showed that the SAr-MeOH extract showed low damage to the rat erythrocytes and the concentration tested on guineapig ileum had no toxic effect. This suggested that SAr-MeOH had low or no toxicity when tested in vivo. It was also shown that the SAr-MeOH extract had secondary metabolites with low toxicity and a potential spasmolytic activity on guineapig ileum. On the other hand, the extract did not show any effect on guineapig trachea.

Studies were conducted to determine the cytotoxic potential of the crude ethanolic extract from Sargassum polyceratium (Sarg-EtOH) in rat erythrocytes and investigate its spasmolytic activity on guineapig ileum. For the determination of the effect of the Sarg-EtOH extract on rat erythrocytes, blood was collected from fasting rats to obtain erythrocytes. Sarg-EtOH extract was added to the erythrocyte suspension at various concentrations and in different preparations and the percentage of haemolysis was calculated. For the effect of Sarg-EtOH extract on carbachol- and histamine-induced phasic contractions on the guineapig ileum, the inhibition of response to submaximal carbachol or histamine was assessed by comparing the responses before (control) and after addition of the extract. The molar concentration of the Sarg-EtOH extract that reduced the response to an agonist by 50% was obtained by non-linear regression. Results showed that the Sarg-EtOH extract did not show significant cytotoxic effects in rat erythrocytes, which showed that the Sarg-EtOH extract had low or no toxicity. The Sarg-EtOH extract also showed significant non-selective spasmodic activity on guineapig ileum.