A Comprehensive Toxicological Assessment of Fulvic Acid

Study on adsorption behavior of humic acid on aluminum in Enteromorpha prolifera

High level of aluminum content in Enteromorpha prolifera posed a growing threat to both its growth and human health. This study focused on exploring the factors, impacts, and process of removing aluminum from Enteromorpha prolifera using humic acid. The results showed that under experimental conditions of 0.0330 g·L-1 humic acid concentration, pH 3.80, 34 °C, and a duration of 40 min, the removal rate was up to 80.18%. The levels of major flavor components, proteins, and amino acids in Enteromorpha prolifera increased significantly after treatment, while polysaccharides and trace elements like calcium and magnesium decreased significantly. Infrared spectroscopy demonstrated that the main functional groups involved in binding with Al3+ during humic acid adsorption were hydroxyl, carboxyl, phenol, and other oxygen-containing groups. The adsorption process of Al3+ by humic acid was a spontaneous phenomenon divided into three key stages: fast adsorption, slow adsorption, and adsorption equilibrium, which resulted from both physical and chemical adsorption effects. This study provided a safe and efficient method in algae metal removal.

The protective effects and potential mechanisms of fulvic acid against ethanol-induced gastric mucosal injury in mice

Fulvic acid (FA) is a kind of natural organic acids extracted from lignite, which is the active ingredient in Wujin oral liquid, a proprietary Chinese medicine used to treat gastric and duodenal ulcers. However, our understanding of the mechanisms of FA remains limited. Currently, the protection of FA and its mechanism were explored using the ethanol-induced gastric mucosal injury mouse model. The histopathological examinations showed FAs at three doses effectively reduced gastric congestion, oedema caused by ethanol, and prevented gastric epithelial cell fall-off. When compared to the model group, FAs reduced IL-1β and IL-6 levels in serum, as well as IL-1β, IL-6, TNF-α, and COX-2 expression levels in tissue. Furthermore, FAs significantly inhibited p65, P38 MAPK, and Erk1/2 phosphorylation in damaged gastric tissue. It was indicated FA has good protection against ethanol-induced gastric mucosa injuries in mice and this effect was related to NF-κB and MAPK signalling pathways.

Natural fulvic acids inhibit non-small-cell lung cancer through the COX-2/PGE2/EP4 axis: In silico and in vivo assessments

Purpose

Non-small-cell lung cancer (NSCLC) is a major public health concern with a high incidence worldwide. Coal-derived fulvic acids (FAs) contain functional groups in their chemical structures. Overexpression of cyclooxygenases-2 (COX-2), prostaglandin E2 (PGE2), and the PGE2 receptor EP4 subtype (EP4) can have a potential link with the increased tumor incidence and promoted tumor growth and metastasis in NSCLC. This study aimed to assess the biological roles of coal-derived FAs in the growth and development of NSCLC and to elucidate the underlying molecular mechanisms.

Methods

A web-based tool for predicting small-molecule pharmacokinetics (pkCSM) was used to analyze the absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of FAs. Molecular docking and dynamic simulations were performed to analyze the binding affinities of COX-2 and EP4 to FA. An acute toxicity test and an antitumor study were used to analyze the toxicity and anti-NSCLC effects of FAs. Thirty NSCLC-bearing nude mice were randomly divided into five groups (six mice per group): vehicle control, positive control with 20 mg/kg body weight (BW) 5-fluorouracil, and three treatments with 25, 50, and 100 mg/kg BW FAs. The BW and tumor volume were recorded, and the COX-2, PGE2, and EP4 protein expression were measured and analyzed.

Results

Using the predictive pkCSM algorithm, we found that FA did not cause developmental toxicity. Molecular simulations revealed that COX-2 and EP4 expression was inhibited by FA. An acute toxicity test conformed that the maximum tolerated FAs dose was >3.0 g/kg BW. The animal study demonstrated that FA treatment significantly downregulated the expression of COX-2, PGE2, and EP4 in NSCLC-bearing mice compared to that in vehicle control mice (p < 0.01).

Conclusions

Natural FAs may exert anti-NSCLC effects through the COX-2/PGE2/EP4 axis.

Effects of sodium humate and glutamine combined supplementation on growth performance, diarrhea incidence, blood parameters, and intestinal microflora of weaned calves

This experiment was conducted to investigate the effects of sodium humate (HNa) and glutamine (Gln) alone or combined supplementation on growth performance, diarrhea incidence, blood parameters, and intestinal microflora of weaned Holstein calves. In a 14-day experiment, 40 calves at 51 ± 3 days of age were randomly allocated to four treatment groups: (1) NC (basal diet), (2) NC + 5% HNa, (3) NC + 1% Gln, and (4) NC + 5% HNa + 1% Gln. Calves combined supplementation with HNa and Gln had a higher (P < .05) ADG, serum concentration of glucose (GLU), IgA, and IgG but lower fecal scores, diarrhea incidence, serum concentration of TNF-α, and IL-10 compared with NC group (P < .05). Compared with NC group, HNa + Gln group showed higher (P < .05) serum GSH and T-AOC activities but lower (P < .05) concentration of MDA and D-lac. Furthermore, the abundances of Prevotella ruminicola, Bifidobacterium, and Lactobacillus in rectal digesta were increased (P < .05), but the Escherichia coli was significantly decreased. In conclusion, combined supplementation with HNa and Gln can effectively improve the immune status, antioxidant capacity, and intestinal microflora of the weaned calves while reducing diarrhea incidence.