The promising antioxidant effects of lignans: Nrf2 activation comes into view.

Lignans are biologically active compounds widely distributed, recognized, and identified in seeds, fruits, and vegetables. Lignans have several intriguing bioactivities, including anti-inflammatory, antioxidant, and anticancer activities. Nrf2 controls the expression of many cytoprotective genes. Activation of Nrf2 is a promising therapeutic approach for treating and preventing diseases resulting from oxidative injury and inflammation. Lignans have been demonstrated to stimulate Nrf2 signaling in a variety of in vitro and experimental animal models. The review summarizes the findings of fourteen lignans (Schisandrin A, Schisandrin B, Schisandrian C, Magnolol, Honokiol, Sesamin, Sesamol, Sauchinone, Pinoresinol, Phyllanthin, Nectandrin B, Isoeucommin A, Arctigenin, Lariciresinol) as antioxidative and anti-inflammatory agents, affirming how Nrf2 activation affects their pharmacological effects. Therefore, lignans may offer therapeutic candidates for the treatment and prevention of various diseases and may contribute to the development of effective Nrf2 modulators.

The combination of olive oil and Lepidium sativum improves the deleterious effects resulting from dexamethasone-induced osteoporosis in rats.

INTRODUCTION: Osteoporosis is characterized by deterioration of bone microarchitecture and reduced bone mass and can increase the risk of fracture. To reduce this risk, the aim of this study was to compare the combination effects of olive oil and Lepidium sativum compared to the conventional drug therapy alendronate. METHODS: Osteoporosed-induced rat model was established by administration of dexamethasone in female adult albino rats. The serum level of Ca2+, P3+, and osteocalcin was assessed. In addition, histopathological changes and immunohistochemical expression of osteopontin within bone specimens were performed. RESULTS: Our results showed that a combination of olive oil and Lepidium sativum had a beneficial therapeutic effect in the treatment of osteoporosis as compared to alendronate therapy. This was demonstrated by increase of serum Ca2+, P3+, and osteocalcin levels in treated compared to control groups. Intriguingly, the highest effect was noticed in rats that received a combination of olive oil and Lepidium sativum compared to the individual treatment. This was reflected by an increase in the cortical bone thickness and a decrease in immunohistochemical expression of osteopontin compared to individual treated groups. CONCLUSION: We concluded that the administration of a combination of olive oil and Lepidium sativum improves bone mineral health and intensity and reduces the risk of osteoporosis in a rat model.

Anti-inflammatory and cytotoxic specialised metabolites from the leaves of Glandularia × hybrida.

In our ongoing effort to investigate active specialised metabolites from genus Glandularia, phytochemical studies on the ethanolic extract of Glandularia × hybrida (Groenl. & Rümpler) G.L. Nesom & Pruski leaves resulted in the isolation of three undescribed compounds, a dibenzylbutyrolactolic lignan and two echinocystic acid based triterpenoid saponins, in addition to two known compounds. Interestingly, this study reports isolation of chemo-systematically valuable specialised metabolites for the first time from the genus under investigation. Additionally, the isolated metabolites were evaluated for their iNOS inhibition and cytotoxic activities using a combination of in silico and in vitro studies. The pharmacokinetics properties (ADMET) of some of the isolated compounds were determined using pkCSM-pharmacokinetics server. Molecular docking analysis showed that saponin compound possesses higher negative score (-9.59 kcal/mol) than the lignan compound (-6.56 kcal/mol). The isolated compounds also showed iNOS inhibition activity with IC50 values ranging between 6.6 and 49.7 µM and significant cytotoxic activity against a series of cell lines including SK-MEL, KB, BT-549, SK-OV-3, LLC-PK1 and VERO cells. Hence, this study reveals that specialised metabolites from G. hybrida plant are of significant anti-inflammatory and cytotoxicity potentials.

Phytoconstituents from Adenanthera pavonina L. as antioxidants and inhibitors of inducible TNF-α production in BV2 cells.

Adenanthera pavonina L. has been used traditionally to relieve inflammation. This study aimed to expand the phytochemical knowledge of A. pavonina and evaluate its constituents for their antioxidant and anti-inflammatory potentials as tumor necrosis factor alpha (TNF-α) inhibitors. The antioxidant activity was evaluated using the DPPH radical scavenging assay, and the inhibition of TNF-α was assessed through ELISA and qRT-PCR techniques. Interestingly, five previously undescribed metabolites, including a pentadienoic acid derivative, a triterpenoid glycoside, and three tamarixetin glycosides, were identified alongside seven known compounds. Most compounds evaluated had higher DPPH radical scavenging capabilities than the standard, trolox. Tamarixetin 3-O-(α-ʟ-rhamnopyranosyl)-(1→2)-ß-ᴅ-galactopyranoside (11), a previously undescribed compound, was the most effective at suppressing TNF-α protein and m-RNA levels. Other flavonoid glycosides, quercetin 3-O-(α-ʟ-rhamnopyranosyl-(1→2)-ß-ᴅ-xylopyranoside (4), isovitixin (5), and quercetin-3-O-[α-ʟ-rhamnopyranosyl-(1→2)]-[α-ʟ-rhamnopyranosyl-(1→6)]-ß-ᴅ-galactopyranoside (9), also significantly lowered TNF-α production.

Phytochemical constituents and antioxidant activity of Echinops albicaulis.

Two thiophenes; 5-(3-buten-1-ynyl)-2,2'-bithiophene (2) and α-tertthienyl (9), two alkaloids; echinopsine (10) and echinorine (11), three flavonoids; genkwanin (5), apigenin (6), and rutin (7), two triterpenoids; lupeol acetate (1) and lupeol linoleate (4), together with 2,6,10-trimethyldodeca-2,6,10-triene (4) and ß-sitosterol glucoside (8) were isolated from the aerial parts of Echinops albicaulis. Antioxidant, antimicrobial and antiprotozoal activities were evaluated. E. albicaulis aqueous methanolic extract (50, 10, and 1 mg/mL) showed significant antioxidant activity comparable to the potent antioxidant, N-acetyl cysteine, moreover, the aqueous methanolic extract (1 mg/mL) significantly reduced intracellular reactive oxygen species in active cell cultures of human peripheral blood mononuclear cells under oxidative stress more than the reference antioxidant N-acetyl cysteine. None of the isolated compounds showed antimicrobial or antiprotozoal activities at concentration up to 20 µg/mL.