Quantification of biomarkers and evaluation of antioxidant, anti-inflammatory, and cytotoxicity properties of Dodonaea viscosa grown in Saudi Arabia using HPTLC technique

Dodonaea viscosa (Sapindaceae) was collected from Riyadh, Saudi Arabia. For the simultaneous measurement of quercetin and kaempferol, a validated high-performance thin-layer chromatography (HPTLC) approach was devised in D. viscosa leaf extract. The antioxidant activity was evaluated using diphenyl 1-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. Moreover, the cytotoxic effect was tested against three cancer cell lines A549, HepG2, and MDA-MB-231. The potential anti-inflammatory properties of different fractions of D. viscosa were also evaluated using lipopolysaccharide (LPS)-induced THP-1 macrophages cells. The test samples include a crude extract of leaves and its solvent-soluble fractions of D. viscosa. The results showed that the crude extract and its fractions exhibited various significant biological activities, the fraction of chloroform demonstrated the highest free radical scavenging activity with IC50 values: 172.2 and 257.7 µg/mL for both DPPH and ABTS tests. Additionally, the chloroform fraction had the greatest cytotoxic activity against MDA-MB-231 (IC50 values: 24.6 ± 0.4 µg/mL). Moreover, the chloroform fraction exhibited the highest downregulation of the LPS-induced expression of TNF-α and IL-6. Quercetin and kaempferol were estimated concurrently in leaves crude extract using a validated technique on an HPTLC plate (10 cm2 × 10 cm2) with a combination of toluene–ethyl acetate–formic acid (5:4:0.2; v/v/v) as the mobile phase and a λ max of 254 nm. The amount of quercetin and kaempferol was found to be 31.8 and 15.01 mg/g of dried leaf extract, respectively. The presence of high levels of quercetin and kaempferol in D. viscosa leaves extract could explain its remarkable antioxidant, cytotoxic, and anti-inflammatory effects. The devolved HPTLC method can be used for routine analysis and standardization of D. viscosa crude plant material, extracts, and/or finished products using quercetin and kaempferol as appropriate markers.