Antioxidant and Anticancer Properties of Functionalized Ferrocene with Hydroxycinnamate Derivatives-An Integrated Experimental and Theoretical Study

Unveiling the antiglioblastoma potential of harmicens, harmine and ferrocene hybrids

The poor prognosis of glioblastoma multiforme, inadequate treatment options, and growing drug resistance urge the need to find new effective agents. Due to the significant anti-cancer potential of harmicens, hybrid compounds which comprise harmine/β-carboline and ferrocene moiety, we investigated their antiglioblastoma potential in vitro and mechanism of action (inhibition of DYRK1A, Hsp90, anti-oxidative activity). The results have shown that triazole-type harmicens, namely 5, with a ferrocene moiety in C-3 position of the β-carboline ring (IC 50 = 3.7 ± 0.1 µmol L-1, SI = 12.6) and ., the C-6 substituted harmicene (IC 50 = 7.4 ± 0.5 µmol L-1, SI = 5.8) exert remarkable activity and selectivity against human malignant glioblastoma cell line (U251) in vitro. On the other hand, amide-type harmicens 10, 12, and 14 exhibited strong, but non-selective activity, in the low micro-molar range. Mechanistic studies revealed that among active compounds, amide-type harmicens 12 and 14 inhibit DYRK1A and Hsp90 CTD, whereas compound 14 showed pronounced antioxidative activity. Therefore, the antiproliferative activity of harmicens might be a combination of complex molecular interactions.

In vivo anticoccidial, antioxidant, and anti-inflammatory activities of avocado fruit, Persea americana (Lauraceae), against Eimeria papillata infection

Apicomplexan parasites, especially Eimeria sp., are the main intestinal murine pathogens, that lead to severe injuries to farm and domestic animals. Many anticoccidial drugs are available for coccidiosis, which, leads to the development of drug-resistant parasites. Recently, natural products are considered as an alternative agent to control coccidiosis. This study was designed to evaluate the anticoccidial activity of the Persea americana fruit extract (PAFE) in male C57BL/6 mice. A total of 35 male mice were divided into seven equal groups (1, 2, 3, 4, 5, 6, and 7). At day 0, all groups except the first group which served as uninfected-untreated control were infected orally with 1 × 10³E. papillata sporulated oocysts. Group 2 served as uninfected-treated control. Group 3 was considered an infected-untreated group. After 60 min of infection, groups 4, 5, and 6 were treated with oral doses of PAFE aqueous methanolic extract (100, 300, and 500 mg/kg of body weight, respectively). Group 7 was treated with amprolium (a reference drug for coccidiosis). PAFE with 500 mg/kg, was the most effective dose, inducing a significant reduction in the output of oocysts in mice feces (by about 85.41%), accompanied by a significant decrease in the number of the developmental parasite stages and a significant elevation of the goblet cells in the jejunal tissues. Upon treatment, a significant change in the oxidative status due to E. papillata infection was observed, where the levels of glutathione (GSH) increased, while, levels of malondialdehyde (MDA) and nitric oxide (NO) were decreased. In addition, the infection significantly upregulated the inflammatory cytokines of interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and interferon-γ (IFN-γ). This increase in mRNA expression of IL-1β, TNF-α, and IFN-γ was about 8.3, 10.6, and 4.5-fold, respectively, which significantly downregulated upon treatment. Collectively, P. americana is a promising medicinal plant with anticoccidial, antioxidant, and anti-inflammatory activities and could be used for the treatment of coccidiosis.

Attenuation of hexaconazole induced oxidative stress by folic acid, malic acid and ferrocenecarboxaldehyde in an invertebrate model Bombyx mori

Fungicides are a class of pesticides used to ward off fungal diseases from agricultural crops to achieve maximum productivity. These chemicals are quite efficient in controlling diseases; however, the excessive use of these affects non-target organisms as well. In this study, Bombyx mori was utilized to investigate the effect of the pesticide hexaconazole (HEX) on the antioxidant system of this organism and also to find ways to mitigate it. On oral exposure to this chemical, a significant reduction in antioxidants, CAT, GPX, GSH, and SOD in the gut, fat body, and silk gland was observed. The HEX treatment also resulted in lipid peroxidation (LPO) in all the three tissues. To mitigate this toxicity and protect the silkworm from oxidative stress, we tested three compounds, namely folic acid, ferrocenecarboxaldehyde, and malic acid having known antioxidant potential. Folic acid provided significant protection against HEX-induced toxicity. Ferrocenecarboxaldehyde and malic acid proved to be ill-efficient in controlling oxidative stress, with ferrocenecarboxaldehyde being the least effective of the three. Folic acid was also efficient in controlling LPO up to a considerable level. Ferrocenecarboxaldehyde and malic acid also prevented LPO less efficiently than folic acid. Overall folic acid was the only compound that mitigated HEX-induced oxidative stress in silkworm with statistical significance in all the tissues viz. gut, fat body, and silk gland.

On the free radical scavenging and metallic ion chelating activities of pyridoxal - Could the pro-oxidant risk be competitive?

Primary and secondary antioxidant activities of pyridoxal have been investigated by using density functional theory (DFT) at the M05-2X level combined with 6-311++G(d,p) basis set for non-metallic atoms and LanL2DZ for metallic ions. The former has been examined by its free radical scavenging activity towards HOO^●, HO^●, and NO₂^●via different mechanisms including formal hydrogen transfer (FHT), proton transfer (PT), single electron transfer (SET), and radical adduct formation (RAF). The latter has been accomplished through its transition metal-chelating ability with Fe(III)/Fe(II) and Cu(II)/Cu(I) ions. The results show that pyridoxal illustrates as an efficient radical scavenger, especially, for HO^● and NO₂^● in water. The overall rate constants (k_overall) for the reactions with HOO^●, HO^●, and NO₂^● radicals are 1.30 × 10⁴, 5.76 × 10⁹, and 1.43 × 10⁹ M^-1s^-1, respectively. The SET from the anionic state is the most dominant for the HOO^● and NO₂^● scavenging reactions, while both RAF and SET contribute largely to the reaction with highly reactive HO^● radicals. Moreover, the anionic form of pyridoxal demonstrates a better role as a metal chelator than the neutral. However, the pro-oxidant risks of the formed complexes could be observed if there are superoxide radical anion (O₂^●-) and ascorbate (Asc^-) in aqueous media.

On The Radical Scavenging and DNA Repairing Activities by Natural Oxygenated Diterpenoids: Theoretical Insights

Diterpenoids are abundant and important compounds in Euphorbia species owing to their structural diversity; therefore, in this study, we investigate the modern-concept antioxidant activities, including free-radical scavenging and oxidative DNA damage repairing, of highly oxygenated diterpenoids originating from the aerial part of Euphorbia helioscopia. Four compounds with structural types of ent-abietane, containing a fused furan ring in their structures, including euphelionolide A (1), euphelionolide D (2), euphelionolide I (3), and euphelionolide L (4) are selected. First, the radical-scavenging activity of these compounds was evaluated with two typical radicals HOO^• and HO^• in water and pentyl ethanoate (PEA, to mimic lipid environment) via three main mechanisms, namely, hydrogen atom transfer (HAT), radical adduct formation (RAF), and single electron transfer. It is found that the studied compounds are able to scavenge free radicals at multiple reactive sites favorably via HAT and RAF mechanisms, in which the former dominates in the case with HOO^• while both mechanisms are competitive in the reaction with HO^•. Second, chemical repairing of DNA damage is modeled with the H-atom and single electron being transferred from the studied molecules to damaged 2'-deoxyguanosine (2dG) (i.e., 2dG^• radicals and 2dG^•+ radical cation). Among the four compounds, euphelionolide A is shown as the most effective radical scavenger and also the highest potential species for chemical repairing of radical-damaged DNA in both water and PEA.

New insights into the competition between antioxidant activities and pro-oxidant risks of rosmarinic acid

Direct and indirect antioxidant activities of rosmarinic acid (RA) based on HOO˙/CH3OO˙ radical scavenging and Fe(iii)/Fe(ii) ion chelation were theoretically studied using density functional theory at the M05-2X/6-311++G(2df,2p) level of theory. First, four antioxidant mechanisms including hydrogen atom transfer (HAT), radical adduct formation (RAF), proton loss (PL) and single electron transfer (SET) were investigated in water and pentyl ethanoate (PEA) phases. Regarding the free radical scavenging mechanism, HAT plays a decisive role with overall rate coefficients of 1.84 × 103 M-1 s-1 (HOO˙) and 4.49 × 103 M-1 s-1 (CH3OO˙) in water. In contrast to PL, RAF and especially SET processes, the HAT reaction in PEA is slightly more favorable than that in water. Second, the [Fe(iii)(H2O)6]3+ and [Fe(ii)(H2O)6]2+ ion chelating processes in an aqueous phase are both favorable and spontaneous especially at the O5, site-1, and site-2 positions with large negative Δr G 0 values and great formation constant K f. Finally, the pro-oxidant risk of RA- was also considered via the Fe(iii)-to-Fe(ii) complex reduction process, which may initiate Fenton-like reactions forming reactive HO˙ radicals. As a result, RA- does not enhance the reduction process when ascorbate anions are present as reducing agents, whereas the pro-oxidant risk becomes remarkable when superoxide anions are found. The results encourage further attempts to verify the speculation using more powerful research implementations of the antioxidant activities of rosmarinic acid in relationship with its possible pro-oxidant risks.