Background: The star fruit [Averrhoa carambola L (Oxalidaceae)] is traditionally used in the treatment of many ailments in many countries. It possesses several pharmacological activities, including antioxidant and anti-inflammatory effects. However, it contains the neurotoxic caramboxin and its high content of oxalic acid limits its consumption by individuals with compromised kidney function. This study assessed the anti-hyperlipidemic and antioxidant activities of different fractions of the methanolic extract of A. carambola leaves (MEACL). Methods: The antioxidant activity was investigated using FRAP, and ABTS and DPPH radical-scavenging assays and the inhibitory activity toward pancreatic lipase (PL) and HMG-CoA reductase was assayed in vitro. Acute hyperlipidemia was induced by poloxamer-407 (P-407) in rats and different fractions of MEACL (n-hexane, chloroform, n-butanol, ethyl acetate (EA), water, and chloroform) were orally administered. Cholesterol and triglycerides were determined at 0, 12, 24, and 48 h and LDL-C, vLDL-C, HDL-C, lipid peroxidation (LPO) and antioxidants were assayed after 48 h. The expression of ABCA1, ABCG5, ABCG8, LDL-R, SREBP-1, and SREBP-2 and the activity of HMG-CoA reductase were assayed in the liver of P-407-administered rats treated with the EA fraction. Results: The in vitro data revealed potent radical-scavenging activities of MEACL fractions with the most potent effect showed by the EA fraction that also suppressed the activities of HMG-CoA reductase and PL. In P-407-induced hyperlipidemic rats, all fractions prevented dyslipidemia as shown by the decrease in total cholesterol, triglycerides, LDL-C, vLDL-C and atherogenic index. MEACL and its fractions prevented LPO and boosted GSH, superoxide dismutase, glutathione peroxidase, and catalase in P-407-administered rats. The EA fraction showed more effective anti-hyperlipidemic and antioxidant effects than other fractions and downregulated SREBP-2 while upregulated ABCA1 and LDL-R and ameliorated LPL and HMG-CoA reductase in hyperlipidemic rats. Conclusion: MEACL showed in vitro and in vivo antioxidant activity and the EA fraction significantly ameliorated dyslipidemia in a rat model of P-407-induced acute hyperlipidemia by modulating LPL, PL, HMG-CoA reductase, and cholesterolgenesis-related factors. Therefore, the leaves of A. carambola represent a safe alternative for the star fruit particularly in kidney disease patients, and the EA is the most effective anti-hyperlipidemic and antioxidant fraction.
Aflatoxin B1 (AFB1) is a significant pollutant found in food and feed, posing a threat to public health. The objective of this study was to assess the effect of Lactiplantibacillus plantarum (LACP) against AFB1 in growing rabbits by investigating growth, serum metabolites, immunity, antioxidant capacity, and inflammatory response. A total of 60 growing male rabbits (721.5 ± 2.68g) were allocated to 4 experimental groups. The control group receiving only a basal diet, the AFB1 group (0.3 mg AFB1/kg diet), the LACP group (1 × 109 cfu/g /kg diet), and the combination group (1 × 109 cfu/g + 0.3 mg AFB1/kg diet; AFB1+ LACP) for 8 wk. The administration of AFB1 alone significantly decreased the final body weight, body gain, and feed intake, while significantly increasing the feed conversion ratio (P < 0.05). A significant decline in total proteins and globulins, along with elevated levels of hepatic enzymes (AST, ALP, ALT, and GGT) and renal function markers (creatinine and uric acid), were observed in the AFB1-contaminated group (P < 0.05). Immunoglobulins (IgG and IgM) were significantly decreased, alongside a significant elevation of triglycerides, direct bilirubin, and indirect bilirubin in growing rabbits fed diets with AFB1 (P < 0.05). Supplementing the AFB1 diet with LACP restored the growth reduction, improved liver (AST, ALP, ALT, and GGT) and kidney (creatinine and uric acid) functions, and enhanced immune markers in rabbit serum (P < 0.05). Antioxidant indices (SOD, GSH, and CAT) were significantly decreased in the AFB1 group (P < 0.05). However, the addition of LACP to the AFB1-contaminated diets improved antioxidant capacity and malondialdehyde (MDA) and protein carbonylation (PC) in hepatic tissues of rabbits (P < 0.05). Serum interlukin-4 (IL-4) and interferon gamma (IFN-γ) levels were significantly increased in the AFB1 group (P < 0.05), but the addition of LACP significantly reversed this elevation. AFB1 downregulated the expression of immune-inflammatory genes such Nrf2, IL-10, and BCL-2 genes, while up-regulating the caspase-3 (CASP3) gene (P < 0.05). Supplementing AFB1 diet with LACP significantly decreased the expression of immune-inflammatory genes (Nrf2, IL-10, and BCL-2) and reduced the expression of the apoptotic-related gene CASP3. This study highlights the potential of L. plantarum (1 × 109 cfu/g /kg diet) as a protective agent against AFB1 in growing rabbits by enhancing antioxidant and immune function and reducing apoptosis and inflammation pathways.