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Galangal (Alpinia galanga (L.) Willd) and bitter ginger (Zingiber zerumbet (L.) Roscoe) are aromatic rhizomatous plants that are typically used for culinary purposes. These rhizomatous plants have many biological properties and the potential to be beneficial for pharmaceutics. In this study, we evaluated the antioxidant and antimicrobial activities, with a specific focus on acne-causing bacteria, as well as the phytochemical constituents, of different parts of galangal and bitter ginger. The rhizomes, stems, and leaves of galangal and bitter ginger were separately dried for absolute ethanol and methanol extractions. The extracts were used to evaluate the antioxidant activity using a DPPH radical scavenging assay (0.005–5000 μg/mL), antimicrobial activity against acne-causing bacteria (0.50–31.68 mg/mL), and in vitro cytotoxicity toward human keratinocytes and fibroblasts (62.5–1000 μg/mL), as well as analyses of bioactive phytochemicals via GC-MS and LC-MS/MS (500 ppm). The ethanol and methanol extracts of bitter ginger and galangal's rhizomes (BRhE, BRhM, GRhE, and GRhM), stems (BStE, BStM, GRhE, and GRhM), and leaves (BLeE, BLeM, GLeE, and GLeM), respectively, showed antioxidant and antimicrobial activities. The extracts of all parts of bitter ginger and galangal were greatly antioxidative with 0.06–1.42 mg/mL for the IC50 values, while most of the extracts were strongly antimicrobial against C. acnes DMST 14916, particularly BRhM, BRhE, GRhM, and GRhE (MICs: 3.96–7.92 mg/mL). These rhizome extracts had also antimicrobial activities against S. aureus TISTR 746 (MICs: 7.92–31.68 mg/mL) and S. epidermidis TISTR 518 (MICs: 7.92–15.84 mg/mL). The extracts of bitter ginger and galangal rhizomes were not toxic to HaCaT and MRC-5 even at the highest concentrations. Through GC-MS and LC-MS/MS analysis, phytochemicals in bitter ginger rhizome extracts, including zerumbone, tectorigenin, piperic acid, demethoxycurcumin, and cirsimaritin, and galangal rhizome extracts, including sweroside and neobavaisoflavone, were expected to provide the antioxidant and anti-microbial activities. Therefore, the results suggest that the bitter ginger and galangal extracts could be natural anti-acne compounds with potential for pharmaceutic, cosmetic, and aesthetic applications. [ABSTRACT FROM AUTHOR]

This investigation examined the nutritional value, mineral content, total phenolic content, antioxidant activity and cytotoxicity of uncooked and cooked Krabok seeds. Proximate analysis was carried out to determine the nutrient composition of uncooked and cooked Krabok seeds. The average fat, protein, carbohydrate, moisture, ash, and fiber contents were found to be 75.42, 11.78, 6.72, 2.68, 1.85 and 1.54 %, respectively. The Folin-Ciocalteu method was employed for the quantitative analysis of total phenolic compounds. All 6 samples of Krabok seeds extracted, both cooked and uncooked, were extracted using hexane, ethyl acetate, and ethanol, and subjected to the test. All the extracted samples contained phenolic compounds, with amounts ranging from 29.10 to 130.26 µg GAE/mL. The highest levels of phenolic compounds were observed in the ethanolic extract of cooked Krabok seeds. The antioxidant properties were evaluated using the DPPH assay. The scavenging activity of the extracted Krabok seed samples ranged from 9.84 to 62.31 %. The ethanolic extract of uncooked Krabok seeds exhibited the highest antioxidant activity. To assess the toxicity of the Krabok seed extract, HaCaT, Vero and RAW 264.7 cell liness were employed using the MTT technique. The results revealed that cell survival remained above 80 % for all doses of both uncooked and cooked Krabok seed extracts. These findings suggest that Krabok seeds are a valuable source of fat and other essential nutrients. The crude ethanolic extract exhibited a significant amount of phenolic content and antioxidant activity. Therefore, it could be utilized in the production of snacks or cosmetics. [ABSTRACT FROM AUTHOR]

Abstract: Novel antioxidant and anti‐inflammatory peptides were isolated from hydrolysates of Siamese crocodile (Crocodylus siamensis) hemoglobin. C. siamensis hemoglobin hydrolysates (CHHs) were obtained by pepsin digestion at different incubation times (2, 4, 6, and 8 H) at 37 °C and subjected to antioxidant and anti‐inflammatory activity assessment. CHH obtained by 2‐H hydrolysis (2H‐CHH) showed the highest anti‐inflammatory activity with respect to decreasing nitric oxide (NO) production, whereas the strongest antioxidant activity was found for 6‐H hydrolysis (6H‐CHH) against nitric oxide radicals. To evaluate the anti‐inflammatory and antioxidant activity of individual peptide components, 2H‐CHH and 6H‐CHH were purified by semipreparative HPLC. Peptide fraction P57 isolated from 6H‐CHH was found to exhibit the highest nitric oxide radical inhibition activity (32.0%). Moreover, purification of 2H‐CHH yielded peptide fraction P16, which displayed a high efficacy in decreasing NO production of macrophage RAW 264.7 cells (83.2%) and significantly reduced proinflammatory cytokines and inflammatory mediators interleukin‐6 (IL‐6), interleukin‐1 beta (IL‐1β), and prostaglandin‐E2 (PGE2) production to about 2.0, 0.3, and 1.9 ng/mL, respectively. Using LTQ orbitrap XL mass spectrometry, active peptide sequences were identified as antioxidant KIYFPHF (KF7), anti‐inflammatory SAFNPHEKQ (SQ9), and IIHNEKVQAHGKKVL (IL15). Additionally, CHHs simulated gastric and intestinal in vitro digestion positively contributed to antioxidant and anti‐inflammatory activity. Taken collectively, the results of this work demonstrate that CHHs contain several peptides with anti‐inflammatory and antioxidant properties, which may prove valuable as treatment or supplement against diseases associated with inflammation and oxidative stress. [ABSTRACT FROM AUTHOR]