Effects of Drying Methods on Antioxidant, Anti-Inflammatory, and Anticancer Potentials of Phenolic Acids in Lovage Elicited by Jasmonic Acid and Yeast Extract

The study presents the effect of drying methods (traditional, convection, microwave, and freeze-drying) on the content and bioactivity (determined as antioxidative, anti-inflammatory, and antiproliferative potential) of potentially bioavailable fractions of phenolic acids contained in lovage elicited with jasmonic acid (JA) and yeast extract (YE) and in untreated control leaves. The highest amount of syringic acid was recorded in the convectionally dried lovage samples, while ethanolic extracts from lyophilized lovage had the highest content of protocatechuic and caffeic acids. The drying method significantly influenced the tested properties only in some cases. The traditional drying resulted in lower antioxidant potential, while convectional drying caused a reduction of the lipoxygenase inhibition ability of the samples after simulated digestion. Samples containing the control and elicited lovage leaves dried with convectional and traditional methods exhibited the highest cytotoxicity against a prostate cancer epithelial cell line.

Antioxidant, Anti-Inflammatory and Anticancer Activities of Methanolic Extract of Thottea siliquosa: An In Vitro and In Silico Study

Background: Oxidative stress and inflammation are the predominant cause of chronic diseases including multiple forms of cancers. Due to the prominent roles, prevention of these oxidative stress and inflammation is considered to be a target for preventing these disorders. Various natural products and plant extracts prevent the process of free radical-induced damages. Objectives: The present study evaluated the biological properties of Thottea siliquosa, belonging to the family Aristolochiaceae, which is a traditionally used Ayurvedic plant. Methods: Antioxidant assays carried out were DPPH, FRAP, hydrogen peroxide scavenging, and hemolysis inhibition assay; nitric oxide and lipoxygenase inhibition assays were used for anti-inflammatory studies. Anticancer activity was done using human endometrial and breast cancer cells by MTT assay. Bioactive compounds present in T. siliquosa were identified by LCMS and each was docked with various cancer targets including EGFR, VEGFR, GST, COX2, and Lipooxygenase. Results: The results of the present study showed antioxidant properties for the methanolic crude extract of T. siliquosa as DPPH radical scavenging (110.40 ± 4.5µg/mL), FRAP capacity (41.1 ± 6.2), peroxide scavenging (233.4 ± 14.2µg/mL). Besides, anti-inflammatory properties are also evident in terms of nitric oxide radical scavenging (28.76± 3.9 µg/mL) and lipoxygenase inhibition (39.2 ± 3.2µg/mL) assays. In silico analysis confirmed the inhibitory potential of the bioactive compounds of T. siliquosa against cancer drug targets such as EGFR, VEGFR, and inflammatory enzymes cyclooxygenase as well as lipooxygenase. Further, the anticancer activity of the extract has been identified against human endometrial and breast cancer cells. The possible mechanism of anticancer action of the extract is mediated through the apoptosis induction mediated through increased caspase and APAF-1 expression. Conclusion: The study thus concludes that T. siliquosa showed significant antioxidant, anti-inflammatory and anticancer properties. Further studies together with a bioassay-guided fractionation may identify possible bioactive compounds.

Synthesis, Neuroprotection, and Antioxidant Activity of 1,1′-Biphenylnitrones as α-Phenyl-N-tert-butylnitrone Analogues in In Vitro Ischemia Models

Herein, we report the neuroprotective and antioxidant activity of 1,1′-biphenyl nitrones (BPNs) 1–5 as α-phenyl-N-tert-butylnitrone analogues prepared from commercially available [1,1′-biphenyl]-4-carbaldehyde and [1,1′-biphenyl]-4,4′-dicarbaldehyde. The neuroprotection of BPNs1-5 has been measured against oligomycin A/rotenone and in an oxygen–glucose deprivation in vitro ischemia model in human neuroblastoma SH-SY5Y cells. Our results indicate that BPNs 1–5 have better neuroprotective and antioxidant properties than α-phenyl-N-tert-butylnitrone (PBN), and they are quite similar to N-acetyl-L-cysteine (NAC), which is a well-known antioxidant agent. Among the nitrones studied, homo-bis-nitrone BPHBN5, bearing two N-tert-Bu radicals at the nitrone motif, has the best neuroprotective capacity (EC50 = 13.16 ± 1.65 and 25.5 ± 3.93 μM, against the reduction in metabolic activity induced by respiratory chain blockers and oxygen–glucose deprivation in an in vitro ischemia model, respectively) as well as anti-necrotic, anti-apoptotic, and antioxidant activities (EC50 = 11.2 ± 3.94 μM), which were measured by its capacity to reduce superoxide production in human neuroblastoma SH-SY5Y cell cultures, followed by mononitrone BPMN3, with one N-Bn radical, and BPMN2, with only one N-tert-Bu substituent. The antioxidant activity of BPNs1-5 has also been analyzed for their capacity to scavenge hydroxyl free radicals (82% at 100 μM), lipoxygenase inhibition, and the inhibition of lipid peroxidation (68% at 100 μM). Results showed that although the number of nitrone groups improves the neuroprotection profile of these BPNs, the final effect is also dependent on the substitutent that is being incorporated. Thus, BPNs bearing N-tert-Bu and N-Bn groups show better neuroprotective and antioxidant properties than those substituted with Me. All these results led us to propose homo-bis-nitrone BPHBN5 as the most balanced and interesting nitrone based on its neuroprotective capacity in different neuronal models of oxidative stress and in vitro ischemia as well as its antioxidant activity.

Lipoxygenase Inhibition by Plant Extracts

Lipoxygenases are widespread enzymes that catalyze oxidation of polyunsaturated fatty acids (linoleic, linolenic, and arachidonic acid) to produce hydroperoxides. Lipoxygenase reactions can be desirable, but also lipoxygenases can react in undesirable ways. Most of the products of lipoxygenase reactions are aromatic compounds that can affect food properties, especially during long-term storage. Lipoxygenase action on unsaturated fatty acids could result in off-flavor/off-odor development, causing food spoilage. In addition, lipoxygenases are present in the human body and play an important role in stimulation of inflammatory reactions. Inflammation is linked to many diseases, such as cancer, stroke, and cardiovascular and neurodegenerative diseases. This review summarized recent research on plant families and species that can inhibit lipoxygenase activity.