Anti-Obesity and Gut Microbiota Modulation Effect of Secoiridoid-Enriched Extract from Fraxinus mandshurica Seeds on High-Fat Diet-Fed Mice

Abstract

Previously we conducted a phytochemical study on the seeds of Fraxinus excelsior and isolated nine secoiridoid compounds with adipocyte differentiation inhibitory activity and peroxisome proliferator activated receptor alpha (PPARα) activation effects. However, the bioactive constituents and functions of Fraxinus mandshurica seeds have not been studied. In the present study, we investigated the secoiridoid compounds in F. mandshurica seed extract (FM) using column chromatography, 1H-NMR, 13C-NMR and HPLC-DAD methods. The pancreatic lipase inhibitory activities of isolated compounds were evaluated in vitro. Additionally, the anti-obesity and gut microbiota modulation effect of FM on high-fat diet-induced obesity in C57BL/6 mice were also studied in vivo. The results showed that 19 secoiridoids were isolated from FM and identified. The total content of secoiridoids in FM reached 181.35 mg/g and the highest content was nuzhenide (88.21 mg/g). All these secoiridoid compounds exhibited good pancreatic lipase inhibitory activity with inhibition rate ranged from 33.77% to 70.25% at the concentration of 100 μM. After obese mice were administrated with FM at 400 mg/kg.bw for 8 weeks, body weight was decreased by 15.81%. Moreover, FM could attenuate the lipid accumulation in serum and liver, relieve the damage in liver and kidney, and extenuate oxidative stress injury and inflammation caused by obesity in mice. FM could also modulate the structural alteration of gut microbiota in obese mice, increasing the proportion of anti-obesity gut microbiota (Bacteroidetes, Bacteroidia, S24-7 and Allobaculum), and reducing the proportion of obesogenic gut microbiota (Firmicutes and Dorea). This study suggests that F. mandshurica seeds or their secoiridoids may have potential for use as a dietary supplement for obesity management.

Structural characteristics and immunostimulatory activity of sea cucumber tendon polysaccharides in cyclophosphamide-induced Balb/c mice

“…Some research has proved that the proportions of Firmicutes : Bacteroidetes are significantly increased in obese people and this could be an important factor in the risk of metabolic disorders in host animals and human health metabolic disorders. 50,51…”

“…Some research has proved that the proportions of Firmicutes : Bacteroidetes are significantly increased in obese people and this could be an important factor in the risk of metabolic disorders in host animals and human health metabolic disorders. 50,51 The intestinal flora displays important roles in the regulation of the intestinal immune barrier. It is believed that probiotics, such as Lactobacillaceae, Bifidobacteriaceae and Prevotellaceae, not only resist the colonization of pathogenic bacteria in the intestinal epithelium, but also improve the intestinal mucosal barrier function by promoting the immune…”

Postnatal prebiotic supplementation in rats affects adult anxious behaviour, hippocampus, electrophysiology, metabolomics, and gut microbiota

“…The Dorea genus, however, has not, to our knowledge, been reported to correlate with anxiety levels. An increase of the Dorea genus is found in diabetes (Li et al., 2020) and in rodents fed a high-fat diet ( Guo et al, 2020 ; Velazquez et al., 2019 ). Various strains of the Dorea genus have been implicated as markers of insulin resistance and inflammation ( Brahe et al., 2015 ).…”

The Impact of Host Genotype, Intestinal Sites and Probiotics Supplementation on the Gut Microbiota Composition and Diversity in Sheep

“…From our results, Clostridiales was the significant order-making SHS, having the highest abundance of Firmicutes , while S24_7 was the significant family-letting BHBS, having the highest abundance of Bacteroidetes ; families of Bacteroidaceae , Rikenellaceae , and Synechococcaceae were significant for SHBS, having the second highest abundance of Bacteroidetes among breeds. These bacterial families could be considered as anti-obesity markers; for example, S24-7 , as an anti-obesity bacterium, could reduce the proportion of Firmicutes [ 44 ]. The lower abundance of Bacteroidaceae and Rikenellaceae were observed in obese people’s guts [ 45 , 46 ].…”