Toxicity of the different vegetative stages of Amorimia pubiflora to sheep

Toxic plants containing monofluoroacetate (MFA) cause sudden death in livestock in Australia, South Africa and Brazil, causing economic losses to producers. The objective of this study was to determine the amount of MFA present in young leaves, mature leaves, senescent leaves, and seeds of Amorimia pubiflora harvested at different times of the year and to determine their toxic effect on sheep. Samples of Amorimia pubiflora were collected during April, August and December of 2015 and March of 2016, separated according to the vegetative stage (young leaves, seeds, mature leaves, and senescent leaves), dried in an oven, and administered in daily doses of 5 g/kg/body weight (bw) of fresh leaves to sheep through ruminal cannulae. The experiment was divided into four stages according to the time of collection of the plant so that each sheep received a different vegetative stage of the plant (young leaves, mature leaves, and senescent leaves). Only in the second stage of the experiment was it possible to collect A. pubiflora seeds, which were administered using the same method used for the administration of the leaves. The sheep were dosed with the plant until they showed clinical signs of toxicosis or until the plant was no longer available. Aliquots of leaves and seeds of A. pubiflora were analyzed for MFA concentration. The seeds and young leaves had higher concentrations of MFA than did the mature (harvested in August and December) and senescent (harvested in December) leaves. However, all vegetative stages of the plant were toxic and caused fatal poisoning. The results of our study showed that A. pubiflora is toxic to sheep even when MFA concentrations are low, demonstrating that the presence of this substance is a risk factor for the occurrence of poisoning. Knowing the toxic principle and its variations allow us to determine the conditions for the occurrence of plant toxicosis as well as possible treatment, control, and prophylaxis methods, contributing significantly to the reduction of economic losses on farms due to plant poisoning.

[Acute toxicity study of Aspidopterys obcordata aqueous extract in Sprague-Dawley rats]

OBJECTIVE

To examine the acute toxicity of an aqueous extract of Aspidopterys obcordata (A. obcordata) in Sprague Dawley rats.

METHODS

The rats were orally administered a dose of 5000 mg/kg body weight and observed continuously for 6 h and then daily for 14 days. Control rats were administered distilled water. The effect of the extract on general behavior, body weight, and food and water intake were measured. After 14 days, the rats were sacrificed and their organs (liver, heart, spleen, lungs, kidney, adrenal glands, ovaries, and testes) were removed for macroscopic examination. The body and organ weights in addition to hematology (e.g., hemoglobin and white blood cell counts) and clinical blood biochemistry (e.g., albumin and bilirubin) were also examined.

RESULTS

There were no deaths recorded, and the rats treated with A. obcordata showed no signs of toxicity. All measured parameters in rats treated with A. obcordata were unaffected when compared with those in control rats. The acute toxicity (LD50) was estimated to be > 5000 mg/kg body weight.

CONCLUSION

Our results demonstrate the safety of an acute oral administration of an aqueous extract of A. obcordata in rats and indicate that future subacute and long-term toxicity testing of A. obcordata is warranted.

Anti-inflammatory, anti-hyperalgesic, antiplatelet and antiulcer activities of Byrsonima japurensis A. Juss. (Malpighiaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Decoctions or infusions of the stem bark of Byrsonima japurensis A. Juss. (Malpighiaceae) are widely used as an anti-inflammatory drug in folk medicine of Amazonas State (Brazil).

AIM OF THE STUDY

To evaluate the pharmacological potential of an aqueous extract of the stem bark of Byrsonima japurensis (BJEA) to scientifically verify of its traditional use.

MATERIALS AND METHODS

Anti-inflammatory, antihyperalgesic and antiulcer activities were evaluated in Wistar rats, a Hippocratic screening was performed in Swiss mice to evaluate the toxic effects, and antiplatelet evaluation was performed in human platelet rich plasma assay. Additionally, antioxidant activity was evaluated by superoxide radical scavenging method and β-carotene bleaching test.

RESULTS

Anti-inflammatory, antihyperalgesic and gastroprotective activities were observed in rats treated orally with different doses of BJEA. While signals of toxicity were observed in the mice treated with a very high dose of extract (5000mg/kg), no death occurred. BJEA also showed expressive antiplatelet and antioxidant activities in vitro.

CONCLUSION

According to our results, it was concluded that stem bark of Byrsonima japurensis has significant and safe anti-inflammatory activity, which is closely related with their potent antioxidant activity, supporting the folk medicinal use of this species.

Antidepressant effect and pharmacological evaluation of standardized extract of flavonoids from Byrsonima crassifolia

Byrsonima crassifolia (Malpighiaceae) has been used in traditional medicine for the treatment of some mental-related diseases; however, its specific neuropharmacological activities remain to be defined. The present study evaluates the anxiolytic, anticonvulsant, antidepressant, sedative effects produced by the extracts of Byrsonima crassifolia, and their influence on motor activity in ICR mice. Additionally, we determine the acute toxicity profiles of the Byrsonima crassifolia extracts and the presence of neuroactive constituents. Our results show that the methanolic extract of Byrsonima crassifolia produces a significant (P<0.05) antidepressant effect in the forced swimming test in mice at 500 mg/kg dose. However, it does not possess anxiolytic, sedative, or anticonvulsant properties, and does not cause a reduction of mice locomotion (P>0.05). Although the main compound of the methanolic extract was identified as quercetin 3-O-xyloside (12 mg/kg), our findings suggest that flavonoids, such as rutin (4.4 mg/kg), quercetin (1.4 mg/kg) and hesperidin (0.7 mg/kg), may be involved in the antidepressant effects. To the best of our knowledge, the present study constitutes the first report on the presence of the flavonoids with neuropharmacological activity rutin and hesperidin in Byrsonima crassifolia. In conclusion, the present results showed that the methanolic extract standardized on flavonoids content of Byrsonima crassifolia possesses potential antidepressant-like effects in the FST in mice, and could be considered as relatively safe toxicologically with no deaths of mice when orally administered at 2000 mg/kg.