By Mr. Rival Yuhendri, Universiti Malaysia Kelantan
| 1 | Question from Ms. Nik Fatin Qharanie Binti Nik Mohd Kamaruzaman, 2025-07-29, 11:15:39 AM | Assalamualaikum Mr. Rival, may I ask what the rationale was behind selecting a concentration of 1000 µg/mL for the antioxidant and antibacterial assays of Curcuma sumatrana extracts and fractions? | Answer from the presenter, 2025-07-29, 11:54:46 AM | Waalaikumsalam warahmatullahi wabarakatuh, Thank you for your question regarding the rationale behind the selection of the 1000 µg/mL concentration in the antioxidant and antibacterial assays of C. sumatrana extracts and fractions. For the antioxidant assay, a concentration of 1000 ppm (µg/mL) is commonly used as the highest dose in preliminary screening studies to identify the potential biological activity of plant extracts and fractions. This concentration allows researchers to observe any notable radical scavenging effects. However, if no inhibition value of 50% or higher is obtained at this concentration, the extract is considered to have no significant antioxidant activity. For the antibacterial assay using the disc diffusion method, concentrations of 50 mg/mL, 100 mg/mL, and 200 mg/mL are also commonly employed in early-stage screenings. These concentrations are adequate to detect visible zones of inhibition against bacterial strains, especially when testing crude extracts and semi-purified fractions. I hope this explanation provides clarity. Please feel free to reach out if you have any further questions. |