Crocus sativus L. Petal Extract Inhibits Inflammation and Osteoclastogenesis in RAW 264.7 Cell Model

Quercetin and kaempferol from saffron petals alleviated hydrogen peroxide-induced oxidative damage in B16 cells

BACKGROUND

Saffron petals are usually considered as waste after saffron harvest. However, saffron petals contain many important phytochemical components (e.g. quercetin and kaempferol), which may alleviate oxidative damage in human cells.

RESULTS

The contents of flavonoids and crocin in different parts of saffron were analyzed. The protective effects of flavonoids from saffron on oxidative damage of B16 cells were investigated. Saffron stigma contained high contents of crocin and picrocrocin, whereas flavonoid content (quercetin, 4.03 ± 0.33 mg g-1 DW; kaempferol, 47.80 ± 0.60 mg g-1 DW) was higher in saffron petals than in other parts. Incubation of B16 cells with quercetin (10-30 μmol L-1) and kaempferol (20-30 μmol L-1) obtained from saffron extracts could significantly increase the total antioxidant capacity (T-AOC) and the activity of NADPH:dehydrogenase quinone-1 (NQO1) to alleviate H2O2-induced oxidative damage. Quercetin was better than kaempferol in increasing NQO1 activity and T-AOC. Quercetin extracted from saffron petals could induce NQO1 expression through regulating kelch-like ECH-associated protein-1/nuclear factor erythroid 2-related factor-2 signaling pathway to protect B16 cells from oxidative damage.

CONCLUSION

The content of kaempferol-3-O-sophoroside and quercetin-3-O-sophoroside was higher in saffron petals than in other parts of saffron. The kaempferol and quercetin obtained from saffron petals could enhance the activity of antioxidant enzyme NQO1 and T-AOC in B16 cells. This indicated that saffron petals, as a potential functional food, may prevent diseases caused by oxidative stress. © 2024 Society of Chemical Industry.

Exploring Phenolic Compounds Extraction from Saffron (C. sativus) Floral By-Products Using Ultrasound-Assisted Extraction, Deep Eutectic Solvent Extraction, and Subcritical Water Extraction

Saffron (Crocus sativus) floral by-products are a source of phenolic compounds that can be recovered and used in the nutraceutical, pharmaceutical, or cosmetic industries. This study aimed to evaluate the phenolic compounds' extraction using green extraction techniques (GETs) in saffron floral by-products and to explore the influence of selected extraction techniques on the phytochemical composition of the extracts. Specifically, ultrasound-assisted extraction (UAE), subcritical water extraction (SWE), and deep eutectic solvents extraction (DESE) were used. Phenolic compounds were identified with (HR) LC-ESI-QTOF MS/MS analysis, and the quantitative analysis was performed with HPLC-PDA. Concerning the extraction techniques, UAE showed the highest amount for both anthocyanins and flavonoids with 50:50% v/v ethanol/water as solvent (93.43 ± 4.67 mg/g of dry plant, dp). Among SWE, extraction with 96% ethanol and t = 125 °C gave the best quantitative results. The 16 different solvent mixtures used for the DESE showed the highest amount of flavonoids (110.95 ± 5.55-73.25 ± 3.66 mg/g dp), while anthocyanins were better extracted with choline chloride:butane-1,4-diol (16.0 ± 0.80 mg/g dp). Consequently, GETs can be employed to extract the bioactive compounds from saffron floral by-products, implementing recycling and reduction of waste and fitting into the broader circular economy discussion.

Equisetum arvense standardized dried extract hinders age-related osteosarcopenia

Age-associated osteosarcopenia is an unresolved syndrome characterized by the concomitant loss of bone (osteopenia) and skeletal muscle (sarcopenia) tissues increasing falls, immobility, morbidity, and mortality. Unbalanced resorption of bone in the remodeling process and excessive protein breakdown, especially fast type II myosin heavy chain (MyHC-II) isoform and myofiber metabolic shift, are the leading causes of bone and muscle deterioration in the elderly, respectively. Equisetum arvense (EQ) is a plant traditionally recommended for many pathological conditions due to its anti-inflammatory properties. Thus, considering that a chronic low-grade inflammatory state predisposes to both osteoporosis and sarcopenia, we tested a standardized hydroalcoholic extract of EQ in in vitro models of muscle atrophy [C2C12 myotubes treated with proinflammatory cytokines (TNFα/IFNγ), excess glucocorticoids (dexamethasone), or the osteokine, receptor activator of nuclear factor kappa-B ligand (RANKL)] and osteoclastogenesis (RAW 264.7 cells treated with RANKL). We found that EQ counteracted myotube atrophy, blunting the activity of several pathways depending on the applied stimulus, and reduced osteoclast formation and activity. By in silico target fishing, IKKB-dependent nuclear factor kappa-B (NF-κB) inhibition emerges as a potential common mechanism underlying EQ's anti-atrophic effects. Consumption of EQ (500 mg/kg/day) by pre-geriatric C57BL/6 mice for 3 months translated into: i) maintenance of muscle mass and performance; ii) restrained myofiber oxidative shift; iii) slowed down age-related modifications in osteoporotic bone, significantly preserving trabecular connectivity density; iv) reduced muscle- and spleen-related inflammation. EQ can preserve muscle functionality and bone remodeling during aging, potentially valuable as a natural treatment for osteosarcopenia.

In Vitro Insights into the Role of 7,8-Epoxy-11-Sinulariolide Acetate Isolated from Soft Coral Sinularia siaesensis in the Potential Attenuation of Inflammation and Osteoclastogenesis

The balance between bone-resorbing osteoclasts and bone-forming osteoblasts is essential for the process of bone remodeling. Excessive osteoclast differentiation plays a pivotal role in the pathogenesis of bone diseases such as rheumatoid arthritis and osteoporosis. In the present study, we examined whether 7,8-epoxy-11-sinulariolide acetate (Esa), a marine natural product present in soft coral Sinularia siaesensis, attenuates inflammation and osteoclastogenesis in vitro. The results indicated that Esa significantly inhibited lipopolysaccharide (LPS)-induced inflammation model of RAW264.7 cells and suppressed receptor activator for nuclear factor-κB ligand (RANKL)-triggered osteoclastogenesis. Esa significantly down-regulated the protein expression of iNOS, COX-2, and TNF-α by inhibiting the NF-κB/MAPK/PI3K pathways and reducing the release of reactive oxygen species (ROS) in RAW264.7 macrophages. Besides, Esa treatment significantly inhibited osteoclast differentiation and suppressed the expression of osteoclast-specific markers such as NFATC1, MMP-9, and CTSK proteins. These findings suggest that Esa may be a potential agent for the maintenance of bone homeostasis associated with inflammation.

Bioactive Components and Biological Activities of Crocus sativus L. Byproducts: A Comprehensive Review

The production of saffron spice results in numerous byproducts, as only 15 g of spice can be produced from 1 kg of flowers, indicating that over 90% of the saffron flower material is eventually discarded as waste. In view of this, the paper reviews current knowledge on the natural active components in saffron byproducts and their biological activities, aiming to lay a theoretical and scientific foundation for the further utilization. Saffron byproducts contain a variety of phytochemical components, such as flavonoids, anthocyanins, carotenoids, phenolic acids, monoterpenoids, alkaloids, glycosides, and saponins. The activities of saffron byproducts and their mechanisms are also discussed in detail here.

Bioactivity and applications of saffron floral bio-residues (tepals): a natural by-product for the food, pharmaceutical, and cosmetic industries

Saffron "Crocus sativus" is a plant of the Iridaceae family. Its therapeutic virtues have been known since antiquity; it is used in traditional medicine and culinary preparations. It is also known for its use in cosmetics because of its beneficial pharmacological activities for human skin. In particular, saffron tepals are the main by-product of saffron processing; they contain several bioactive compounds such as mineral agents, anthocyanins, monoterpenoids, carotenoids, flavonoids, and flavonols (kaempferol). This review aims to describe the different properties of saffron flower tepals, including their botanical characteristics, phytochemical composition, biological activities, and cosmetology and perfumery uses.