Pharmacological Ascorbate Elicits Anti-Cancer Activities against Non-Small Cell Lung Cancer through Hydrogen-Peroxide-Induced-DNA-Damage.

Non-small cell lung cancer (NSCLC) poses a significant global health burden with unsatisfactory survival rates, despite advancements in diagnostic and therapeutic modalities. Novel therapeutic approaches are urgently required to improve patient outcomes. Pharmacological ascorbate (P-AscH-; ascorbate at millimolar concentration in plasma) emerged as a potential candidate for cancer therapy for recent decades. In this present study, we explore the anti-cancer effects of P-AscH- on NSCLC and elucidate its underlying mechanisms. P-AscH- treatment induces formation of cellular oxidative distress; disrupts cellular bioenergetics; and leads to induction of apoptotic cell death and ultimately reduction in clonogenic survival. Remarkably, DNA and DNA damage response machineries are identified as vulnerable targets for P-AscH- in NSCLC therapy. Treatments with P-AscH- increase the formation of DNA damage and replication stress markers while inducing mislocalization of DNA repair machineries. The cytotoxic and genotoxic effects of P-AscH- on NSCLC were reversed by co-treatment with catalase, highlighting the roles of extracellular hydrogen peroxide in anti-cancer activities of P-AscH-. The data from this current research advance our understanding of P-AscH- in cancer treatment and support its potential clinical use as a therapeutic option for NSCLC therapy.

Antioxidant, Anti-Skin-Aging, Anti-Inflammatory, and Anti-Acetylcholinesterase Activities of Rourea oligophlebia Extracts.

The objective of this study was to evaluate the antioxidant, anti-skin-aging, anti-inflammatory, and anti-acetylcholinesterase activities of the hexane (n-hex), AcOEt, BuOH, MeOH, and aqueous extracts from R. oligophlebia roots. The total phenolic and flavonoid contents (TPC and TFC) were determined using Folin-Ciocalteu and AlCl3 colorimetric assays. The antioxidant capacity was examined by reducing power (RP), ferric reducing antioxidant power (FRAP), ABTS⋅+ , and DPPH⋅+ radical cation assays. All extracts potentially exhibited antioxidant activity with IC50 values ranging from 2.93 to 5.73 µg/mL for ABTS⋅+ and from 5.69 to 7.65 µg/mL for DPPH⋅+ except the n-hex extract. The BuOH, MeOH, and aqueous extract possess promising anti-skin-aging activities, as observed by an attenuation of UV-A toxicity on human keratinocytes. We proposed that these anti-skin-aging properties are possibly due to direct scavenging activity against reactive oxygen species and upregulate cellular antioxidant machinery. Moreover, we found that the antioxidant capacity was well correlated with anti-inflammatory capacity against nitric oxide (NO) production in terms of the n-hex, AcOEt, and BuOH extracts with IC50 values from 23.21 to 47.1 µg/mL. In contrast, these activities were found to be poorly correlated with AchE activity. To the best of our knowledge, this is the first report of the antioxidant, anti-skin-aging, anti-inflammatory, and anti-acetylcholinesterase activities of the extracts of R. oligophlebia roots. These findings indicated that this species could be a potential source of natural antioxidant, anti-aging, and anti-inflammatory agents. Consequently, it may be suggested as a medicinal plant that prevents diseases related to oxidative stress and inflammatory responses.

Anti-Inflammatory Activity of Oxyresveratrol Tetraacetate, an Ester Prodrug of Oxyresveratrol, on Lipopolysaccharide-Stimulated RAW264.7 Macrophage Cells.

Oxyresveratrol (OXY) has been reported for its anti-inflammatory activity; however, the pharmaceutical applications of this compound are limited by its physicochemical properties and poor pharmacokinetic profiles. The use of an ester prodrug is a promising strategy to overcome these obstacles. In previous researches, several carboxylate esters of OXY were synthesized and oxyresveratrol tetraacetate (OXY-TAc) was reported to possess anti-melanogenic and anti-skin-aging properties. In this study, in addition to OXY-TAc, two novel ester prodrugs of OXY, oxyresveratrol tetrapropionate (OXY-TPr), and oxyresveratrol tetrabutyrate (OXY-TBu), were synthesized. Results from the Caco-2-permeation assay suggested that synthesized ester prodrugs can improve the membrane-permeation ability of OXY. The OXY-TAc exhibited the most significant profile, then this prodrug was chosen to observe anti-inflammatory activities with lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Our results showed that OXY-Tac significantly alleviated secretion of several pro-inflammatory mediators (nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α)), mitigated expression of enzyme-regulated inflammation (inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2)), and suppressed the MAPK cascades. Interestingly, the observed anti-inflammatory activities of OXY-TAc were more remarkable than those of its parent compound OXY. Taken together, we demonstrated that OXY-TAc improved physicochemical and pharmacokinetic profiles and enhanced the pharmacological effects of OXY. Hence, the results in the present study would strongly support the clinical utilities of OXY-TAc for the treatment of inflammation-related disorders.

Some Antioxidant Properties of Components from the Flower of Ochna integerrima and Their Beneficial Effects on HaCaT Keratinocytes and in Silico Analysis on Tyrosinase.

Four compounds, luteolin (1), 6-γ,γ-dimethylallylquercetin 7-O-ß-D-glucopyranoside (2), 6-γ,γ-dimethylallylkaempferol 7-O-ß-D-glucopyranoside (3), and 6-γ,γ-dimethylallyldihydrokaempferol 7-O-ß-D-glucoside (4), were isolated for the first time from AcOEt extract of the O. integerrima flower. We then evaluated the antioxidant effects of AcOEt, butanol, and MeOH extracts and their effects on H2 O2 against oxidative stress in HaCaT keratinocyte cell lines. Furthermore, 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH⋅) radical scavenging activities of 1-4 were determined and their mechanisms of action on tyrosinase were predicted by in silico studies. The results revealed that the AcOEt extract and 1-3 exhibited good DPPH⋅ radical scavenging activity. Furthermore, this extract also had a significant protective effect against H2 O2 -induced oxidative stress in HaCaT cells. In silico studies indicated that the activity of 1-3 may be due to tyrosinase inhibition with MM-GBSA free binding energies of -78.9, -70.1, and -71.1 kcal mol-1 , respectively, compared to 4 with an energy -56.9 kcal mol-1 .

Increase water solubility of Centella asiatica extract by indigenous bioenhancers could improve oral bioavailability and disposition kinetics of triterpenoid glycosides in beagle dogs.

A newly standardised extract of Centella asiatica (Centell-S) with better water solubility than the previous standardised extract of C. asiatica (ECa 233) was developed, and pharmacokinetic profiles of bioactive triterpenoids were investigated in beagle dogs. The test substances were administered via intravenous or oral administration with single and multiple doses for 7 days. The concentrations of major bioactive triterpenoids, including madecassoside, asiaticoside, madecassic acid, and asiatic acid, in biological samples were measured by liquid chromatography-tandem mass spectrometry. The dogs in this study showed good tolerability to all test substances, based on the physical appearance and blood chemistry 24 h after dosing. The major bioactive triterpenoids found in systemic blood circulation were madecassoside, asiaticoside, and asiatic acid; the concentration of these components ranged from 1 to 10,000 µg/L after intravenous administration of 1.0 mg/kg Centell-S. Oral administration of 10 and 20 mg/kg Centell-S generated approximately twofold higher plasma levels of both madecassoside and asiaticoside compared with equivalent doses of ECa 233. In addition, there was an accumulation of triterpenoid glycosides after multiple oral administrations of Centell-S for 7 days, while triterpenic acids showed little tendency for accumulation. Beagles had good tolerability to both standardised extracts of C. asiatica, and showed a similar pattern of bioactive triterpenoids to humans. Centell-S increased oral bioavailability of major triterpenoid glycosides and can be further developed into a phytopharmaceutical product.

Insights into antioxidant activities and anti-skin-aging potential of callus extract from Centella asiatica (L.).

Formation of oxidative stress in dermal fibroblasts plays crucial roles in aging processes of skin. The use of phytochemicals that can promote capacity of fibroblasts to combat oxidative stress is an attractive strategy to prevent skin aging and promote skin beauty. Centella asiatica has been used to treat multitude of diseases for centuries. Previous investigations demonstrated that extracts from C. asiatica have a broad range of beneficial activities through their antioxidant activity. Hence, the extract from this medicinal plant could be a great candidate for anti-skin-aging agent. Callus culture offers a powerful platform for sustainable, rapid and large-scale production of phytochemicals to serve extensive demands of pharmaceutical and cosmeceutical industries. Here, we demonstrated the application of callus culture of Centella asiatica to produce bioactive metabolites. The 50% ethanolic extract of callus culture has distinctive features of chemical compositions and biological profiles. Information from HPTLC-DPPH and HPLC analysis suggested that the callus extract comprises distinctive antioxidant compounds, compared with those isolated from authentic plant. Moreover, results from cell culture experiment demonstrated that callus extract possesses promising antioxidant and anti-skin-aging activities. Pre-treatment with callus extract attenuated H2O2-induced-cytotoxicity on human dermal fibroblasts. The results from RT-qPCR clearly suggested that the upregulation of cellular antioxidant enzymes appeared to be major contributor for the protective effects of callus extract against oxidative stress. Moreover, supplementation with callus extract inhibited induction of matrix metalloprotease-9 following H2O2 exposure, suggesting its potential anti-skin-aging activity. Our results demonstrate the potential utility of C. asiatica callus extract as anti-skin-aging agent in cosmeceutical preparations.

Pharmacologic Ascorbate Primes Pancreatic Cancer Cells for Death by Rewiring Cellular Energetics and Inducing DNA Damage.

The clinical potential of pharmacologic ascorbate (P-AscH-; intravenous delivery achieving mmol/L concentrations in blood) as an adjuvant in cancer therapy is being reevaluated. At mmol/L concentrations, P-AscH- is thought to exhibit anticancer activity via generation of a flux of H2O2 in tumors, which leads to oxidative distress. Here, we use cell culture models of pancreatic cancer to examine the effects of P-AscH- on DNA damage, and downstream consequences, including changes in bioenergetics. We have found that the high flux of H2O2 produced by P-AscH- induces DNA damage. In response to this DNA damage, we observed that PARP1 is hyperactivated. Using our unique absolute quantitation, we found that P-AscH- mediated the overactivation of PARP1, which results in consumption of NAD+, and subsequently depletion of ATP leading to mitotic cell death. We have also found that Chk1 plays a major role in the maintenance of genomic integrity following treatment with P-AscH-. Hyperactivation of PARP1 and DNA repair are ATP-consuming processes. Using a Seahorse XF96 analyzer, we demonstrated that the severe decrease in ATP after challenging with P-AscH- is because of increased demand, not changes in the rate of production. Genetic deletion and pharmacologic inhibition of PARP1 preserved both NAD+ and ATP; however, the toxicity of P-AscH- remained. These data indicate that disruption of bioenergetics is a secondary factor in the toxicity of P-AscH-; damage to DNA appears to be the primary factor. IMPLICATIONS: Efforts to leverage P-AscH- in cancer therapy should first focus on DNA damage.