Phytochemical component and toxicological evaluation of purple sweet potato leaf extract in male Sprague-Dawley rats

Abstract

This study assessed the toxicity of lutein-rich purple sweet potato leaf (PSPL) extract in male Sprague-Dawley rats. Methods and study design: A total of 54 adult male Sprague-Dawley rats were used. For the acute toxicity study, three rats in the acute control group were fed 2,000 mg/kg of PSPL for 14 days. The subacute toxicity study included six rats each in four groups administered 50, 250, 500, or 1,000 mg/kg for 28 days and observed for further 14 days without treatment in the subacute control and subacute satellite groups. Changes in body weight; blood biochemistry; hematological parameters; relative organ weight; and histological sections of the heart, kidney, liver, pancreas, aorta, and retina were observed for signs of toxicity. Results: The gradual increase in weekly body weight, normal level full blood count, normal liver and kidney profile, relative organ weight, and histological sections of all stained organ tissue in the treated group compared with the acute, subacute, and satellite control groups demonstrated the absence of signs of toxicity. Conclusion: Lutein-rich PSPL extract shows no signs of toxicity up to 2,000 mg/kg/day.

Keywords: animal study; bioactive compounds; medicinal plant; phytochemicals; plant extract; purple sweet potato; toxicity.

FIGURE 1

Comprehensive peak characterization trace showing lutein peak from HPLC analyses.

FIGURE 2

Histology section of the AT 2000 and AC groups. No abnormalities in the histological sections of the retina, kidney, liver, pancreas, heart, and aorta of the AT 2000-treated group were observed compared to the AC group. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; OPL, outer plexiform layer; ONL, outer nuclear layer; PL, photoreceptor layer; RPE, retinal pigmented epithelium monolayer; BC, Bowman’s capsule; GLO, glomerulus; iOL, islet of Langerhans; HPL, hepatic portal triad; TI, tunica intima; TM, tunica media; TA, tunica adventitia; N, nucleus; M, myocardium; AC, acute control group; AT 2000, 2,000 mg/kg of PSPL.

FIGURE 3

Histology sections in the subacute studies. No abnormalities in the histological sections of the retina, kidney, liver, pancreas, heart, and aorta of the ST 50, ST 250, ST 500, and ST 1000-treated groups were observed compared to the SC group. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; OPL, outer plexiform layer; ONL, outer nuclear layer; PL, photoreceptor layer; RPE, retinal pigmented epithelium monolayer; BC, Bowman’s capsule; GLO, glomerulus; iOL, islet of Langerhans; HPL, hepatic portal triad; TI, tunica intima; TM, tunica media; TA, tunica adventitia; N, nucleus; M, myocardium; SC, subacute control; ST 50, 50 mg/kg of PSPL; ST 250, 250 mg/kg of PSPL; ST 500, 500 mg/kg of PSPL; ST 1000, 1,000 mg/kg of PSPL.

FIGURE 4

Histology sections for the satellite groups in the subacute studies. No abnormalities in the histological sections of the retina, kidney, liver, pancreas, heart, and aorta of the SST 1000-treated group were observed compared to the SSC group. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; OPL, outer plexiform layer; ONL, outer nuclear layer; PL, photoreceptor layer; RPE, retinal pigmented epithelium monolayer; BC, Bowman’s capsule; GLO, glomerulus; iOL, islet of Langerhans; HPL, hepatic portal triad; TI, tunica intima; TM, tunica media; TA, tunica adventitia; N, nucleus; M, myocardium; SSC, subacute satellite control group; SST, subacute satellite group.