The effect of the aqueous extract of Kohautia grandiflora on paracetamol-induced liver damage in albino rats.

This study was carried out to investigate the hepatoprotective effect of the aqueous extract of Kohautia grandiflora on paracetamol induced hepatotoxicity in rats. A total of 20 albino rats of the Wister strain weighing 120-180 g were used for the study. The animals were divided into 4 groups of 5-rats each [I-IV]. Groups I, II and III served as the normal, paracetamol and plant extract controls and were administered with normal saline, 500 mg/kg of paracetamol and 300 mg/kg of the plant extract respectively for 7 days while rats in group IV served as the treatment group and were pre-treated with 300 mg/kg of the plant extract respectively for 7 days before 500 mg/kg of paracetamol was administered on the 8th day. At the end of the experimental period, blood was obtained from each rat for the determination of serum levels of aspartate transaminase [AST], alanine transaminase [ALT], alkaline phosphatase [ALP], albumin and bilirubin. Biochemical analysis of the serum obtained showed a significant increase [P<0.05] in the levels of AST, ALT, ALP and albumin in rats administered with 500 mg/kg of paracetamol and 300 mg/kg of the extract respectively. Pre-treatment of the animals with the extract caused a decrease in the levels of these enzymes. Histopathological assessments of the liver sections of rats administered with 500 mg/kg of paracetamol and 300 mg/kg of the extract showed congestion of the venous sinusoids, necrosis, edema, mononuclear infiltration and cloudy swellings with the severity higher in the paracetamol treated group. Pre-treatment with 300 mg/kg of the extract revealed a slight hepatoprotection compared with the rats that were administered with paracetamol alone. This study has shown that the aqueous extract of Kohautia grandiflora possesses slight hepatoprotective property.

Effect of the aqueous extract of Psidium guajava on erythromycin-induced liver damage in rats.

The effect of Psidium guajava extract on erythromycin-induced liver damage in albino rats was investigated using 30 normal rats grouped into six. Group I and II served as the normal and treatment controls that were administered with normal saline and 100 mg/kg body weight of erythromycin stearate daily for 14 days respectively. Rats in group III were administered 450 mg/kg body weight of Psidium guajava only for 7 days while rats in groups IV, V and VI were administered Psidium guajava extract for 7 days and 100mg/kg body weight of erythromycin for 14 days. Histopathological investigation of the liver tissues revealed striking oedema and mild periportal mononuclear cell infiltration of hepatic cords in the liver of rats administered 100 mg/kg of erythromycin stearate and 300/450 mg/kg of Psidium guajava extract. Pretreatment with 150 mg/kg of Psidium guajava extract showed a slight degree of protection against the induced hepatic injury caused by 100 mg/kg of erythromycin stearate. Biochemical analysis of the serum obtained revealed a significant increase in serum levels of hepatic enzymes measured in the groups administered with 100 mg/kg of erythromycin stearate and 300/450 mg/kg of Psidium guajava extract compared to the control groups and those pretreated with 150 mg/kg of Psidium guajava extract. This study has shown that the aqueous extract of psidium guajava leaf possesses hepatoprotective property at lower dose and a hepatotoxic property at higher dose but further studies with prolonged duration is recommended.

Sedative effects of the methanolic leaf extract of Newbouldia laevis in mice and rats.

The effect of the methanolic extract of Newbouldia laevis seem on the central nervous system of rats and mice was investigated. The extract was tested on spontaneous motor activity, exploratory behaviour, apomorphine induced climbing behaviour in mice and pentobarbital induced hypnosis in rats. The extract caused considerable reductions of exploratory activity, spontaneous motor activity and prolonged pentobarbitone-induced hypnosis in rats. It was also found to attenuate apomorphine climbing in mice. The results suggest that the methanolic extract of Newbouldia laevis may contain principles that have sedative properties.