Protective effects of Trifolium alexandrinum L. against lung injury induced by environmental toxin CCl4 in experimental rats

Investigating the involvement of the NLRP3/ASC/caspase-1 and NF-κb/MAPK pathways in the pathogenesis of gouty arthritis: Insights from irradiated and non-irradiated Trifolium alexandrium L. extracts and some metabolites

ETHNOPHARMACOLOGICAL RELEVANCE

Trifolium alexandrinum L. (TA), has traditionally been used in folk medicine for its anti-inflammatory properties against hyperuricemia and gout. However, the specific mechanisms of action of TA have not been thoroughly studied.

AIM OF THE WORK

This study aimed to evaluate the protective effects of irradiated (TR25) and non-irradiated (TR0) Trifolium alexandrinum L. aqueous extract (TAAE), along with two isolated compounds, caffeine (CAF) and saponin (SAP), in a rat model of acute gouty arthritis (GA).

MATERIALS AND METHODS

The GA model was established by injecting a monosodium urate (MSU) suspension into the knee joint. Synovial tissue pathology was assessed, and levels of TNF-α, IL-6, IL-1β, NF-κB, mTOR, AKT1, PI3K, NLRP3, and ASC were measured by ELISA. mRNA expression of ERK1, JNK, and p-38 MAPK was detected using qRT-PCR, and Caspase-1 protein expression was assessed by immunohistochemical analysis. Knee swelling, uric acid levels, liver and kidney function, and oxidative stress markers were also evaluated.

RESULTS

TAAE analysis identified 170 compounds, with 73 successfully identified using LC-HR-MS/MS, including caffeine citrate and theasapogenol B glycoside as the main constituents. The studied materials demonstrated significant protective effects against GA. TR25 administration significantly mitigated knee joint circumference compared to other treatments. It demonstrated potential in alleviating hyperuricemia, renal and hepatic impairments induced by MSU crystals. TR25 also alleviated oxidative stress and reduced levels of IL1β, IL-6, TNF-α, and NF-κB. Weak Caspase-1 immune-positive staining was observed in the TR25 group. TR25 decreased NLRP3 and ASC expression, reducing inflammatory cytokine levels in GA. It effectively inhibited the PI3K, AKT, and mTOR signaling pathways, promoting autophagy. Additionally, TR25 suppressed ERK1, JNK, and p-38 MAPK gene expression in synovial tissue. These effects were attributed to various components in TAAE, such as flavonoids, phenolic acids, tannins, alkaloids, and triterpenes.

CONCLUSION

Importantly, irradiation (25 KGy) enhanced the antioxidant effects and phtchemical contents of TAAE. Additionally, TR0, TR25, CAF, and SAP exhibited promising protective effects against GA, suggesting their therapeutic potential for managing this condition. These effects were likely mediated through modulation of the NLRP3/ASC/Caspase-1 and ERK/JNK/p-38 MAPK signaling pathways, as well as regulation of the PI3K/AKT/mTOR pathway. Further research is warranted to fully elucidate the underlying mechanisms and optimize their clinical applications.

The potential therapeutic effects of Trifolium alexandrinum extract, hesperetin and quercetin against diabetic nephropathy via attenuation of oxidative stress, inflammation, GSK-3β and apoptosis in male rats

Diabetic nephropathy (DN) is one of the manifestations of systemic microangiopathy in diabetes. Trifolium alexandrinum extract (TAE) contains biologically active phenolic compounds such as hesperetin (HES) and quercetin, possess various pharmacological properties, including anti-inflammatory, and anti-oxidative potentials. The present study aimed to assess the therapeutic effects and mechanisms underlying the anti-diabetic, antioxidant, and anti-inflammatory effects of HES and quercetin extracted from TAE, and TAE in STZ-induced DN. Male albino rats (170 ± 10 g) were divided into group (1); control rats and groups (2-5); diabetic/HFD were intraperitoneal (i.p.) injected with STZ (35 mg/kg), diabetic rats were randomly classified into STZ, STZ + HES (40 mg/kg), STZ + quercetin (50 mg/kg), and STZ + TAE (200 mg/kg) groups. After 5 weeks, blood and kidney samples were collected for further biochemical, western blotting and histopathological studies. Serum renal functions, renal oxidative status biomarkers and proinflammatory cytokines were determined. The results revealed that there were significant increases in urea, BUN, creatinine, ALP, total protein, albumin, and globulin with a significant decrease in Na⁺ and K⁺ levels, as well as significant elevation in TBARS, TGF-β, TNF-α, IL-6 and the expression levels of GSK-3β, as well as significant decline in TAC, GSH and CAT levels in STZ-treated group compared to the control rats. The previous deleterious alterations were significantly ameliorated after the treatment of diabetic rats with HES, quercetin and TAE. In conclusion, our data demonstrated that HES, quercetin and TAE could be used as potent therapeutic agents to counter DN through antioxidant, anti-inflammatory, and antidiabetic effects.

Effects of phenolic compounds from aqueous extract of Trifolium repens against acetaminophen-induced hepatotoxicity in mice

The aqueous extract of Trifolium repens (TR) leaves was analyzed for the phenolic profile using reversed phase HPLC-DAD and administered to mice against acetaminophen-induced hepatoxicity. Twenty-four phenolic compounds were identified and quantified. The highest amounts present were of kaempferol-3-(caffeoyldiglucoside)-7-glucoside (983.7 µg/ml), followed by p-coumaroyl-4-glucoside (905.6 µg/ml) and daidzein-O-sulfate (808.3 µg/ml). The aqueous extract was administered to mice along with acetaminophen at different doses. Acetaminophen was found to significantly alter body weight, serum biochemistry, and hematological indices of mice, which were ameliorated by the co-administration of aqueous extract. Liver histopathological studies revealed that acetaminophen significantly induced toxicity, while TR aqueous extract provides curative functions. Lipid peroxidation and total reduced glutathione in the liver were also normalized by the aqueous extract of TR. The aqueous extract of TR was rich in important phenolic compounds, which can be used as a source of beneficial bioactive compounds with hepato-protective function. PRACTICAL APPLICATIONS: Acetaminophen has been widely used as antipyretic and analgesic. However, the major complication reported is hepatotoxicity. Synthetic or conventional drugs used for hepatic diseases or against hepatotoxicity are insufficient and causes severe side effects. For this purpose, traditional medicinal plants or nutraceuticals are used to decrease in the side effects of different hepatotoxic medicine are demanding. Food and neutraceuticals are rich in important polyphenolic compounds which are the best antioxidants. This study was aimed to evaluate the phenolic composition of aqueous extract of Trifolium repens and its potential protective action against the acetaminophen-induced toxicity in mice. This study showed for the first time that the aqueous extract of TR was protective against the hepatotoxicity induced by acetaminophen.

Clovamide and clovamide-rich extracts of three Trifolium species as antioxidants and moderate antiplatelet agents in vitro

This in vitro study provides a new insight into the phytochemical, antioxidant, antiplatelet and cytotoxic profiles of commercial trans-clovamide and clovamide-rich extracts, isolated from aerial parts of three Trifolium species (i.e. T. clypeatum L., T. obscurum Savi and T. squarrosum L.). Under inorganic experimental conditions, the EC₅₀ for the investigated substances varied between 4.87 (clovamide) and 7.91 μg/ml (T. clypeatum) according to the DPPH^• assay. The most effective 1 mM ONOO^- scavenger was clovamide (IC₅₀ = 19.29 μg/ml), and the weakest was the T. obsucurum extract (IC₅₀ = 41.79 μg/ml). The antioxidant action of the examined substances (1-50 μg/ml) was also evaluated in blood plasma (under 100 μM ONOO^--induced oxidative stress) using 3-nitrotyrosine, protein thiol groups, lipid hydroperoxides and thiobarbituric acid-reactive substances as biomarkers. All examined substances were more effective in limiting the oxidative damage to blood plasma components than the nitrative damage. Their anti-nitrative action was statistically significant only at the highest concentration (50 μg/ml). Measurements of platelet adhesion and aggregation found the compounds to have moderate antiplatelet properties of up to 20% inhibition of platelet adhesion at concentrations of 1-5 μg/ml. Additionally, clovamide and Trifolium extracts demonstrated no cytotoxicity towards blood platelets or peripheral blood mononuclear cells.