Antioxidant Activities, Acute Toxicity and Chemical Profiling of Torch Ginger (Etlingera elatior Jack.) Inflorescent Extract

Aim/Background: The objectives of the study were to determine total phenolic contents, flavonoid contents, antioxidant activities and assess acute toxicity of torch ginger (Etlingera elatior Jack.) inflorescent hydroethanolic extract. Methods: The analysis of total phenolic contents, total flavonoid contents and antioxidant activities were analyzed spectrophotometrically using micro-titer plate reader. With regard to acute toxicity assessment, Wistar rats were fed with a single dose of torch-ginger either 1.0, 1.5 or 2.0 g extract/kg body weight in comparison with control group. Results: Total phenolic contents, flavonoid contents of the extract were 0.17±0.02 mM gallic acid equivalent/g extract and 0.30±0.01 mM quercetin equivalent/g extract, respectively. The antioxidant evaluation using DPPH radical scavenging assay, FRAP assay and ABTS radical scavenging assay were 0.14±0.08 mg/ml (EC₅₀), 0.13±0.01 mmol Fe²⁺ equivalent/g extract and 0.30±0.12 mM trolox equivalent/g extract, respectively. According to acute toxicity, no mortality or bizarre behavior had been observed throughout 14 days. Clinical chemistry including blood glucose, AST, ALT, BUN, creatinine, total cholesterol, triglyceride, HDL, LDL, total serum protein, albumin, globulin and total bilirubin were in normal ranges and comparable to the control (p<0.05). In conclusion, phenolic compounds and flavonoids of torch-ginger could be measured and indicated the quality of the extract as well as antioxidant activities. Regarding acute toxicity assessment, the extract was safe for experimental animals up to 2.0 g extract/kg body weight. Conclusion: Torch-ginger extract exhibited high amounts of phenolic contents, flavonoid contents, antioxidant activities and was safe in animal model.