Antioxidant and Antiaging Assays of Hibiscus sabdariffa Extract and Its Compounds

Skin aging is a complex biological process due to intrinsic and extrinsic factors. Free radical oxidative is one of extrinsic factors that induce activation of collagenase, elastase and hyaluronidase. Natural product from plants has been used as antioxidant and antiaging. This study aimed to evaluate antioxidant and antiaging properties of Hibiscus sabdariffa extract (HSE) and its compounds including myricetin, ascorbic acid, and β carotene. The phytochemical of H. sabdariffa was determined using modified Farnsworth method and presence of phenols, flavonoids and tannins were in moderate content, whereas triterpenoids and alkaloids were in low content. Total phenolic content performed using Folin-Ciocalteu method, was 23.85 µg GAE/mg. Quantitative analysis of myricetin, β-carotene, and ascorbic acid of HSE was performed with Ultra-High Performance Liquid Chromatography (UHPLC) that shows 78.23 µg/mg myricetin, 0.034 µg/mg β-carotene, whilst ascorbic acid was not detected. HSE has lower activity on DPPH (IC₅₀ = 195.73 µg/mL) compared to β-carotene, the lowest in ABTS assay (IC50 = 74.58 µg/mL) and low activity in FRAP assay (46.24 µM Fe(II)/µg) compared to myricetin, β-carotene. Antiaging was measured through inhibitory activity of collagenase, elastase, and hyaluronidase. HSE had weakest collagenase inhibitory activity (IC₅₀= 750.33 µg/mL), elastase inhibitory activity (103.83 µg/mL), hyaluronidase inhibitory activity (IC₅₀ = 619.43 µg/mL) compared to myricetin, β-carotene, and ascorbic acid. HSE contain higher myricetin compared to β-carotene. HSE has moderate antioxidants and lowest antiaging activities. Myricetin is the most active both antioxidant and antiaging activities.

Anti-inflammatory properties of oolong tea (Camellia sinensis) ethanol extract and epigallocatechin gallate in LPS-induced RAW 264.7 cells

Objective To evaluate the anti-inflammatory activity of oolong tea ethanol extract (OTEE) and epigallocatechin gallate (EGCG) on lipopolysaccharide-induced murine macrophage cell line (RAW 264.7). Methods A cytotoxic assay using MTS tetrazolium was conducted to find a nontoxic level of OTEE and EGCG toward RAW 264.7 cells. Interleukins (IL-6, IL-1β), tumor necrosis factor-α (TNF-α), and cyclooxigenase-2 (COX-2) levels were measured by ELISA, and nitric oxide (NO) levels measured by a nitrate/nitrite colorimetric assay to determine the inhibition activity of OTEE and EGCG. Results Lipopolysaccharide induction increases NO, COX-2, IL-6, IL-1β, and TNF-α levels compared with the untreated cell (negative control). The positive control, lipopolysaccharide-induced RAW 264.7 without treatments showed the highest level of all pro-inflammatory cytokines and modulators tested in this study. The positive control was used as standard to obtain OTEE and EGCG inhibition activity toward NO, COX-2, IL-6, IL-1β, and TNF-α. OTEE had a higher inhibition activity toward NO, COX-2, IL-6, and IL-1β than EGCG; the reverse was seen for TNF-α. However, both OTEE and EGCG suppressed production of NO, COX-2, IL-6, IL-1β, and TNF-α. Conclusions OTEE and EGCG have the potential for use as anti-inflammatory drugs, which is shown by their ability to reduce the production of NO, COX-2, IL-6, IL-1β, and TNF-α in active macrophages.