Pharmacognosy Study and Cytotoxicity of Sengkubak Leaf Extract (Pycnarrhena cauliflora (Miers.) Diels) Against RAW 264.7 Cells

Indonesia possesses abundant biodiversity with considerable potential for the development of alternative treatments for various diseases. Sengkubak (Pycnarrhena cauliflora (Miers.) Diels) is a wild plant found in West Kalimantan and Jambi. This plant has potential as a raw material for herbal medicine development. The objective of this study was to evaluate specific pharmacognostic parameters and cytotoxic activity using the MTT assay. An experimental study was conducted, including phytochemical screening, determination of loss on drying and ash content, and determination of the Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) of ethyl acetate and 70% ethanol extracts. Cytotoxicity against RAW 264.7 cells was evaluated using the MTT assay, with absorbance measured at 570 nm using an ELISA reader. Thin-layer chromatography (TLC) analysis of the sengkubak leaf extracts revealed the presence of alkaloids, phenols, flavonoids, tannins, steroids, and terpenoids. The loss on drying values were 0.97 ± 0.03% for the ethyl acetate extract and 1.62 ± 0.27% for the 70% ethanol extract. The ash content values were 1.76 ± 0.05% and 9.840 ± 0.145% for the ethyl acetate and 70% ethanol extracts, respectively. The TPC values were 49.125 ± 1.253 and 52.481 ± 1.864 mg GAE/g for the ethyl acetate and 70% ethanol extracts, respectively. The TFC values were 42.526 ± 0.002 mg QE/g for the ethyl acetate extract and 28.029 ± 1.002 mg QE/g for the 70% ethanol extract. The antioxidant activity of the sengkubak leaf extracts, determined using the FRAP method, was 532.43 ± 0.427 mol/g for the ethyl acetate extract and 1123.70 ± 2.56 mol/g for the 70% ethanol extract. These values were lower than those observed for quercetin and gallic acid. Cytotoxicity testing showed that the ethyl acetate extract exhibited weak cytotoxic activity against RAW 264.7 cells, with an IC₅₀ value of 302.513 µg/mL, whereas the 70% ethanol extract exhibited very weak cytotoxic activity, with an IC₅₀ value of 813.807 µg/mL. Based on the cytotoxicity results, the safe concentration of the ethyl acetate extract for RAW 264.7 cells was below 62.5 µg/mL, whereas that of the 70% ethanol extract was below 250 µg/mL. In conclusion, the relatively low cytotoxicity of the sengkubak leaf extracts toward RAW 264.7 macrophage cells provides preliminary data supporting further investigation of their potential anti-inflammatory activity.