Protective effects and mechanisms of total alkaloids of Rubus alceaefolius Poir on non‑alcoholic fatty liver disease in rats

The promising roles of medicinal plants and bioactive compounds on hepatic lipid metabolism in the treatment of non-alcoholic fatty liver disease in animal models: molecular targets

Imbalance in hepatic lipid metabolism can lead to an abnormal triglycerides deposition in the hepatocytes which can cause non-alcoholic fatty liver disease (NAFLD). Four main mechanisms responsible for regulating hepatic lipid metabolism are fatty acid uptake, de novo lipogenesis, lipolysis and fatty acid oxidation. Controlling the expression of transcription factors at molecular level plays a crucial role in NAFLD management. This paper reviews various medicinal plants and their bioactive compounds emphasising mechanisms involved in hepatic lipid metabolism, other important NAFLD pathological features, and their promising roles in managing NAFLD through regulating key transcription factors. Although there are many medicinal plants popularly investigated for NAFLD treatment, there is still little information and scientific evidence available and there has been no research on clinical trials scrutinised on this matter. This review also aims to provide molecular information of medicinal plants in NALFD treatment that might have potentials for future scientifically controlled studies.

Natural products that target macrophages in treating non-alcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is the progressive subtype of non-alcoholic fatty liver disease and potentiates risks for both hepatic and metabolic diseases. Although the pathophysiology of NASH is not completely understood, recent studies have revealed that macrophage activation is a major contributing factor for the disease progression. Macrophages integrate the immune response and metabolic process and have become promising targets for NASH therapy. Natural products are potential candidates for NASH treatment and have multifactorial underlying mechanisms. Macrophage involvement in the development of steatosis and inflammation in NASH has been widely investigated. In this review, we assess the evidence for natural products or their active ingredients in the modulation of macrophage activation, recruitment, and polarization, as well as the metabolic status of macrophages. Our work may highlight the possible natural products that target macrophages as potential treatment options for NASH.

Mixture of blackberry leaf and fruit extracts alleviates non-alcoholic steatosis, enhances intestinal integrity, and increases Lactobacillus and Akkermansia in rats

We hypothesized that a mixture of blackberry fruit and leaf extracts may alleviate non-alcoholic fatty liver disease (NAFLD). Rats with diet-induced NAFLD were used to test the hypothesis and explore possible mechanisms. Male Sprague–Dawley rats were orally administered diets 51% of energy from fat and 450 mg dextrin/kg bw (NAFLD-control), 50% ethanol blackberry leaf extract (450 mg/kg bw; BL), 50% ethanol blackberry fruit extract (450 mg/kg bw; BF), the mixture of blackberry leaf and fruit extracts (2:1; 150 mg/kg bw; BLF), and milk thistle extracts (150 mg/kg bw; positive-control) for 12 weeks. Normal-control rats were fed low-fat diets with 450 mg dextrin/kg bw (20 En% fat diet) Body weight, visceral fat mass, liver triglycerides, serum cholesterol, triglyceride, non-esterified fatty acid, and insulin resistance were all elevated in rats in the NAFLD-control group compared to the normal-controls. Rats in the NAFLD-control group exhibited liver damage accompanied by increased oxidative stress and inflammation compared to the rats in the normal-control group. BL and BLF protected the NAFLD rats against the triglyceride and lipid peroxide accumulation, improved insulin sensitivity and dyslipidemia, and increased the antioxidant enzymes, SOD, and GSH-Px, to levels similar to the normal-control group. Further, BL and BLF ameliorated inflammation and hepatocyte damage compared to the NAFLD-controls, and they suppressed mRNA expressions of genes involved in triglyceride synthesis (FAS and SREBP-1c). BLF also modulated the gut microbiota by elevating Lactobacillus and Akkermansia in the feces from the cecum compared to the NAFLD-control group. The integrity of intestinal tissues was improved, and the number of goblet cells was elevated by BLF. In conclusion, BL and BLF prevented high-fat diet-induced liver damage by protecting against oxidation and inflammation-induced injury. BLF (human equivalent 1.3 g/day) might, therefore, be used as a therapeutic agent for NAFLD.

Impact statement

NAFLD is a diet-related metabolic disease with no good drug treatments. Therefore, dietary interventions are needed to alleviate NAFLD. This paper demonstrated that feeding a blackberry leaf and fruit mixture extract can alleviate diet-induced NAFLD in rats. Specifically, the blackberry extract, rich in flavonoids and anthocyanins decreased hepatic triglycerides and lipid peroxides, increased genes related to beta oxidation, decreased those involved fatty acid biosynthesis, alleviated oxidative stress, and suppressed pro-inflammatory cytokine release. The blackberry extract also alleviated gut dysbiosis that was associated with NAFLD by increasing the amount of Lactobacillus and Akkermansia in the feces. This research demonstrated that the extract of a common and inexpensive fruit can help alleviate NAFLD and associated intestinal dysbiosis at a dose equivalent to 1.3 g/day in humans. If this work can be duplicated in humans, it would provide a safe and inexpensive intervention to help alleviate NAFLD.

Toxicological evaluation of Picralima nitida in rodents

Picralima nitida (Stapf) T. Durand and H. Durand (Apocynaceae), over the years has shown wide range of usage in African folk medicine and its safety profile in instances of prolonged use and pregnancy are major concerns. The study aimed to extensively investigate the toxicological effects of Picralima nitida in albino rodents and make appropriate extrapolations to humans. In the first phase of the experiment which evaluated the genotoxicity and subchronic toxicity of P. nitida, a total of 40 albino rats (male and female) were randomized into 4 groups of 10 animals per group. Group 1 (control group) was orally administered with 10 ml/kg of distilled water. Animals in Groups 2 to 4 were administered with aqueous seed extract of the plant at 100, 200, 400 mg/kg body weight/day, respectively. Oral administration at the designated doses was continued for 90 days after which they were sacrificed by cervical dislocation for subchronic toxicological assessment. In the genotoxicity phase, 30 female mice were randomized into 5 groups, the control group was treated with 10 ml/kg of distilled water, groups 2 to 4, treated with 100 mg/kg, 200 mg/kg and 400 mg/kg doses of extract, and the 5th group had cyclophosphamide (0.1 mg/kg). The mice were sacrificed on the 28th day for bone marrow sampling for genotoxicity testing. In the second phase of the experiment which evaluated the teratogenicity of P. nitida, graded doses of the extract were administered to pregnant rats from day 1-19. Three groups of 6 female rats per group were administered 75, 150 and 300 mg/kg aqueous extract of P. nitida and a fourth group of 6 rats used as control was administered distilled water at 10 ml/kg. On day 20, 3 dams from each group were sacrificed and the foetuses were harvested through abdominal incision for physical examination. The 3 remaining dams were allowed to litter. The litters were sacrificed at 6 weeks for biochemical, haematological and histological analyses. The LD₅₀ determined was 707.107 mg/kg. The aqueous seed extract of P. nitida was found to be genotoxic at all the test doses. There were no significant alterations in haematologic and renal parameters following subchronic administration. Notable dynamics were observed in hormonal characteristics: there was a significant dose-dependent reduction in FSH while oestradiol and progesterone showed dose-dependent increase. Furthermore, P. nitida may cause hepatopathy as shown by hepatic venous and sinusoidal congestion on hepatic histology. Also, there is non-significant reduction in total cholesterol and LDL. No significant alteration in glucose level. Furthermore, the extract produced a statistically significant decrease in birth weight (p < 0.0001). The extract induced a significant (p < 0.05) increase in creatinine and transaminase levels in the first filial of group 150 mg/kg. The platelet count was increased in all treated group (p < 0.005). All the histology of kidney in 150 mg/kg group showed vascular congestion. In conclusion, the aqueous seed extract of P. nitida has teratogenic effects and should not be used in pregnant women. Also, P. nitida is highly genotoxic and may cause hepatic damage and depletion of glutathione pool on chronic use, thereby causing oxidative stress and its potential sequelae.

Untargeted Metabolomics Reveals Intervention Effects of Total Turmeric Extract in a Rat Model of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common forms of chronic liver disease. Currently, there are no recognized medical therapies effective for NAFLD. Previous studies have demonstrated the effects of total turmeric extract on rats with NAFLD induced by high-fat diet. In this study, serum metabolomics was employed using UHPLC-Q-TOF-MS to elucidate the underlying mechanisms of HFD-induced NAFLD and the therapeutic effects of TE. Supervised orthogonal partial least-squares-discriminant analysis was used to discover differentiating metabolites, and pathway enrichment analysis suggested that TE had powerful combined effects of regulating lipid metabolism by affecting glycerophospholipid metabolism, glycerolipid metabolism, and steroid hormone biosynthesis signaling pathways. In addition, the significant changes in glycerophospholipid metabolism proteins also indicated that glycerophospholipid metabolism might be involved in the therapeutic effect of TE on NAFLD. Our findings not only supply systematic insight into the mechanisms of NAFLD but also provide a theoretical basis for the prevention or treatment of NAFLD.