Medicinal Lagerstroemia dose designs following γ-sitosterol quantity and human diary need for toxicity testing before use in the antihyperglycemic treatment
Lagerstroemia floribunda and L. macrocarpa were investigated for phytochemicals and toxicity. Phytochemical contents were screened via GC-MS and HPLC with ethanol and hexane extracts. MTT and comet assays were performed on human peripheral blood mononuclear cells (PBMCs). Major phytochemicals contained at higher than 10% were31.83% γ-sitosterol, 10.73% phytol in L. floribunda; 34.97% γ-sitosterol, 13.65% oleamide and 10.56% squalene in L. macrocarpa. MTT assay showed IC50 values as 0.54 and 0.60 mg/ml in L. floribunda and L. macrocarpa ethanol extracts, yet no IC50 values with hexane extracts indicating high cell viability percentage 62.77 ± 1.53-75.28 ± 3.10 and 68.45 ± 3.25-84.39 ± 1.30. The IC50 value predicted LD50 of 1097.62 and 1141.49 mg/kg in L. floribunda and L. macrocarpa, slightly hazardous category of toxic chemicals. Comet assay revealed that the two studied species induced significant DNA damage in PBMCs (p < 0.05). Based on the previous reports that γ-sitosterol possess antihyperglycemic activity, combinations of L. floribunda, L. macrocarpa, L. speciosa and L. indica plants which contained a sufficient amount of γ-sitosterol were evaluated. They displayed no IC50 values but induced significant DNA damage in PBMCs (p < 0.05) amid all combinations. So, consumers should concentrate on their genotoxicity.