Analysis of chemical compounds and toxicological evaluation of Forsythia suspensa leaves tea

Abstract

To determine the compositions of Forsythia suspensa leaves tea (FSLT) and its safety, the chemical compounds were analysed with some methods, and the toxicity was evaluated in Kunming mice and Wistar rats. The results showed that FSLT contained rich flavonoid, lignans, triperpene acids, amino acids, and mineral elements. In the acute toxicity study, none of the mice died, and no obvious poisoning symptoms were observed after 14 days in mice at the dose of 15 mg/g·body weight (bw) FSLT; in the sub-chronic toxicity, no abnormal or dead rat was found at the dose of 1, 3, and 10 mg/g·bw during 90 days feeding administration; there was no significant difference in bw and food consumption; no significant differences were found in each hematology and serum biochemistry parameter and organ/body weight ratio comparing with the control experimental group. The results revealed that the FSLT has low or no toxicity via oral administration. Therefore, FSLT is very suitable and safe to be used as a new resource food.

Keywords: Acute toxicity; Chemical compound; Forsythia suspensa leaves tea (FSLT); Sub-chronic toxicity.

Fig. 1

Total feed intake and feed utilization rate for Wistar rats feed the diet containing F. suspensa leaf tea for 90 days. Control: rats without the leaf tea, T1: rats treated with 1.0 mg/g·bw, T2: rats treated with 3.0 mg/g·bw, T3: rats treated with 10.0 mg/g·bw. Grey bars represents female rats, while black bars represents male rats

Fig. 2

Results of PCE examination and in sperm abnormality examination in Kunming mice treated with different FSLT concentration. NC: mice without FSLT, PC: mice treated with 50.0 mg/g·bw cyclophosphamide, T1: mice treated with 1.25 mg/g·bw, T2: mice treated with 2.5 mg/g·bw, T3: mice treated with 5.0 mg/g·bw. (A) amount of PCE, (B) PCE rate. Different lower case letters for amount of PCE or PCE rate indicate significant differences at p < 0.01

Fig. 3

The serum hematological results in both sex Wistar rats treated with leaf tea for 90 days. (A) WBC, (B) RBC, (C) Hb, (D) lymphocyte, and (E) neutrophil. Control: rats without the FSLT, T1: rats treated with 1.0 mg/g·bw, T2: rats treated with 3.0 mg/g·bw, T3: rats treated with 10.0 mg/g·bw. Grey bars represents female rats, while black bars represents male rats

Fig. 4

The serum biochemical examination in both sex Wistar rats treated with different FSLT concentration for 90 days. (A) GPT, (B) GOT, (C) BUN, (D) CRE, (E) TG, (F) GLU, (G) TC, (H) TP, and (I) ALB. Grey bars represents female rats, while black bars represents male rats