Coffee infused with the additive Eurycoma longifolia, also known as Tongkat ali (TA), has become widely available in the Malaysian market. Safety evaluations for consumption of the products have been called for due to the herbal addition. This study investigates the acute, subacute and chronic effects of a commercial TA coffee in Sprague Dawley rats when given in a single, repeated and prolonged dosage. The dosages of 0.005, 0.05, 0.30 and 2 g/kg body weight (BW) were used in the acute study and 0.14, 0.29 and 1 g/kg BW were used in the repeated dose studies. The in-life parameters measured were food and water intake, body weight and clinical observations. Blood were collected for hematology and clinical biochemistry analyses. All animals were subjected to full necropsies. Non-toxicity-related changes were observed in the food and water consumption parameters. Body weight showed normal increments and none of the animals had any clinical signs of toxicity. Microscopically assessed organ tissues did not reveal any abnormalities. There was significant decrease of platelet count in all the chronic study male treated groups. Significant elevation of renal profile parameters in both gender groups given 0.29 g/kg BW, along with liver and lipid profile elevation in some female groups of the chronic study were noted. No dose-dependent relationship was apparent in the dosage range tested, though these changes may suggest an initial safety indication to the TA coffee. The study concludes that the no observed adverse effect level (NOAEL) for this commercial TA coffee was 1 g/kg BW.

Carica papaya L. leaves have been used in ethnomedicine for the treatment of fevers and cancers. Despite its benefits, very few studies on their potential toxicity have been described. The aim of the present study was to characterize the chemical composition of the leaf extract from ‘Sekaki’ C. papaya cultivar by UPLC-TripleTOF-ESI-MS and to investigate the sub-acute oral toxicity in Sprague Dawley rats at doses of 0.01, 0.14 and 2 g/kg by examining the general behavior, clinical signs, hematological parameters, serum biochemistry and histopathology changes. A total of twelve compounds consisting of one piperidine alkaloid, two organic acids, six malic acid derivatives, and four flavonol glycosides were characterized or tentatively identified in the C. papaya leaf extract. In the sub-acute study, the C. papaya extract did not cause mortality nor were treatment-related changes in body weight, food intake, water level, and hematological parameters observed between treatment and control groups. Some biochemical parameters such as the total protein, HDL-cholesterol, AST, ALT and ALP were elevated in a non-dose dependent manner. Histopathological examination of all organs including liver did not reveal morphological alteration. Other parameters showed non-significant differences between treatment and control groups. The present results suggest that C. papaya leaf extract at a dose up to fourteen times the levels employed in practical use in traditional medicine in Malaysia could be considered safe as a medicinal agent.

The subchronic toxicity effect of the leaf extract of Carica papaya Linn. in Sprague Dawley (SD) rats was investigated in this study. The extract was prepared by dissolving the freeze dried extract of the leaves in distilled water and was administered orally to SD rats (consisted of 10 rats/sex/group) at 0 (control), 0.01, 0.14, and 2 g/kg body weight (BW) for 13 weeks. General observation, mortality, and food and water intake were monitored throughout the experimental period. Hematological and biochemical parameters, relative organ weights, and histopathological changes were evaluated. The study showed that leaf extract when administered for 13 weeks did not cause any mortality and abnormalities of behavior or changes in body weight as well as food and water intake. There were no significant differences observed in hematology parameters between treatment and control groups; however significant differences were seen in biochemistry values, for example, LDH, creatinine, total protein, and albumin. However, these changes were not associated with histopathological changes. In conclusion, the results suggested that daily oral administration of rats with C. papaya leaf extract for 13 weeks at a dose up to fourteen times the levels employed in traditional medicine practice did not cause any significant toxic effect.