Antinutritional factors, toxic elements and phytochemicals present in jatropha curcas fruits, kernels, seeds and ethanol seed extract

Jatropha curcas (J. curcas) seeds have been exploited as a source of biodiesel and for its ethnomedicinal uses and agro feed potential, however, toxic properties have been associated with the seeds. The study was aimed at determining the toxic constituents present in J. curcas fruits, seeds and kernels and ethanol seed extract. Standard methods were employed in the investigations, including those of the Association of Analytical Chemists and Trease and Evans. J. curcas fruits, seeds and kernels from Sierra Leone contained cyanogenic glycosides (in mg/100g) of 7.10, 5.10 and 16.96 while the corresponding values for the Nigeria samples were 11.60, 10.15 and 15.92; all greatly above the maximum permissible limits of 0.05-0.35. Similarly, the tannin contents of the fruits, seeds and kernels from Sierra Leone (1.66, 1.46, and 1.80) and of the seeds and kernels from Nigeria (1.40, 1.48) approximated the maximum permissible limits of 1.5 mg/100g or were higher. In contrast, the phytates and saponins which ranged from 1.78-2.14 and 1.64-2.42 for both sources of J. curcas were significantly below the maximum permissible levels of 500 mg/100g (for phytates) and 100 mg/100g (for saponins). Heavy metals like cadmium, copper, chromium and lead were also detected, but their concentrations were below the maximum permissible limits. These constituents were mostly similar regardless of the country source of Jatropha. Ethanol extract of J. curcas seeds was found to contain toxic phytochemicals and heavy metals. J. curcas as food cannot be ruled out especially for animals since cooking, fermentation and heat treatment can significantly reduce some of these antinutritional factors

PRELIMINARY STUDIES ON THE BEHAVIOURAL EFFECTS OF THE METHANOL EXTRACT OF LEONOTIS NEPETIFOLIA LINN STEM IN MICE.

BACKGROUND: Leonotis nepetifolia Linn (Lamiaceae) is used in traditional medicine for its calming (tranquilizing) effects. The aim of this study was to determine whether there is any scientific justification for this use. To achieve this purpose, we investigated the behavioural effects of the methanol extract of Leonotis nepetifolia stem (37.5, 75 and 150 mg/kg) in mice. METHODS: Acute toxicity studies were carried out on the methanol stem extract of Leonotis nepetifolia to determine the LD50. The behavioural tests employed were diazepam-induced sleep onset and duration, hole board assay for exploratory activity, mouse beam walk assay for motor coordination, and the staircase test for the detection of anxiolytic compounds. Preliminary phytochemical screening was also carried out on the extract. RESULTS: The intraperitoneal LD50 value was found to be 3.8 g/kg. The results showed that the extract significantly prolonged the duration of diazepam-induced sleep at the highest dose (150 mg/kg). There was no observable effect on exploratory activity and motor coordination at the doses tested (37.5, 75 and 150 mg/kg). The extract, however, at 150 mg/kg elicited a significant decrease in the number of rearings in the staircase test, an effect also observed in the group of mice injected with an anxiolytic dose of diazepam. The preliminary phytochemical screening revealed the presence of alkaloids, saponins, glycosides and triterpenoids. CONCLUSION: The results obtained suggest that the crude methanol extract of Leonotis nepetifolia stem possesses some biologically active constituents with potential anxiolytic activity and thus may justify its traditional use as a tranquilizer.

Infectivity of macrophages and the histopathology of cutaneous lesions, liver and spleen is attenuated by leaf extract of Vernonia amygdalina in Leishmania major infected BALB/c mice.

Preliminary investigation of the in vitro and in vivo efficacies of different extracts from the leaves of Vernonia amygdalina (VA), a plant widely used in Nigeria was evaluated in Balb/C mice infected with a laboratory strain of Leishmania major (L. major). The ability of the methanol, hexane and aqueous extracts of the plant to suppress the infection rate and its cytotoxicity on macrophages and L929 cells were determined in the in vitro study. The in vivo study evaluated time course of infection, lesion progression and the histopathology of cutaneous lesions, liver and spleen after inoculation with metacyclic promastigotes. Methanolic extract of VA containing high levels of flavanoids, was the most potent extract as it showed the highest suppression on infectivity and viability of intracellular amastigotes at a concentration lower than that which elicited cytotoxicity on macrophages. Treatment of infected mice with methanolic extract of VA showed delayed onset of disease with a significant reduction in lesion size and attenuation of the histopathological outcome characterised by intact epidermis and less tissue destruction in skin, spleen and liver. In conclusion, these results demonstrate that VA has potent antileishmanial properties which warrants further investigation into the immunological mechanism.

Anti-seizure activity of the aqueous leaf extract of Solanum nigrum linn (solanaceae) in experimental animals.

BACKGROUND: Solanum nigrum is claimed in traditional medical practice, to be useful in the treatment of epilepsy in some parts of Nigeria. OBJECTIVES: To study the anti-convulsant property of the aqueous extract of the leaves of S. nigrum in chicks, mice and rats. METHOD: Aqueous extracts were administered intraperitoneally, at a pre-treatment time of 30 minutes, at graded doses and animals were challenged with different types of proconvulsants. RESULTS: The aqueous leaf extract produced a significantly (P<0.05) dose dependent protection against electrically-induced seizure in chicks and rats, pentylenetetrazole-induced seizure in mice and rats and picrotoxin-induced seizure in mice and rats. The anti-seizure property of the extract was potentiated by amphetamine. CONCLUSION: The result obtained in this study suggests that the leaves of this plant may possess anti-convulsant property in chicks, mice and rats.

Effect of artemether on pentobarbitone sleep and electrical activity in rats.

Artemether (AM), a highly effective treatment for multidrug-resistant malaria and a component of artemisinin combination therapy, has been associated with some neurotoxicity following repeated high doses. This study was aimed at investigating the effect of AM on pentobarbitone sleep and electrical activities in rats. Wistar rats received AM i.p. at 3 dose levels: 1.5, 7.5, and 15 mg/kg, whereas control rats received 0.2 mL of the vehicle (3% v/v Tween 80). AM administered 20 min before pentobarbitone had no significant effect on the onset and duration of sleep. However, after a 7-day pretreatment, AM dose-dependently prolonged pentobarbitone sleep, as did chloramphenicol. Electroencephalogram and electromyogram recordings 20 min after pretreatment showed that AM (15 mg/kg) exhibited inhibitory activity similar to chlorpromazine as opposed to the excitatory effect of amphetamine. When pretreated for 7 days, rats receiving 1.5 mg/kg AM also showed inhibitory activity of the cortical centres, whereas desynchronization of the optic tectum and reticular formation was observed in rats pretreated with 7.5 and 15 mg/kg AM. The present data suggest that although the therapeutic equivalent dose of 1.5 mg/kg AM had no appreciable effects on pentobarbitone sleep but caused reduced electrical activity in rats, higher doses have more profound effects on both indices.

Some pregnancy-related effects of artemether in laboratory animals.

Artemether, highly effective in multi-drug-resistant malaria is not routinely available for use in pregnancy due to the lack of adequate research data in animals and man. This study was therefore aimed at investigating some pregnancy-related effects of artemether. Artemether (1.5, 7.5 and 15 mg/kg i.p. daily for 7 days) did not produce changes in rat oestrous cycle. The drug did not prevent or prolong the rate of conception or parturition, cause pre-term delivery and affect litter size. Birth weight and growth rate of pups from artemether-pretreated dams were within the normal range. Artemether (48-480 microg/ml) had no agonist effect on the isolated uterine smooth muscles of both non-pregnant and pregnant rats and guinea pigs. However, the drug (24- 240 microg/ml) reduced oxytocin-induced contraction of uterine tissues concentration-dependently, particularly in pregnant uteri.