Biochemical and histological impact of Vernonia amygdalina supplemented diet in obese rats

Effect of single and combination therapy on methanol extracts of Khaya senegalensis stem bark, Vernonia amygdalina leaves and Garcinia kola seed in Leptospira interrogans-infected mice

ETHNOPHARMACOLOGICAL RELEVANCE

Pastoralists in Nigeria mix Garcinia kola seed (GK), Khaya senegalensis stem bark (KS), and Vernonia amygdalina leaves (VA) to treat leptospirosis.

AIM

To determine the in vitro and in vivo effect on single and combination therapy on Leptospira interrogans-infected mice.

MATERIALS AND METHODS

Evaluation of in vitro assay for anti-leptospiral motility of the extracts was carried out in triplicates. For the in vivo assessment, 40 adult male mice inoculated with Leptospira were randomly allocated into 8 groups of 5 mice each. Groups IV-IX were treated with 800 mg/kg b.w. of KS, GK, VA, KS + GK, KS + VA, GK + VA for 5 days. Group I was negative control, II was model control, and III was treated with penicillin (3.7 mg/kg b.w.) intramuscularly.

RESULTS

In vitro, at 90 min, all the extracts at 800, 400, and 200 mg/ml showed complete cessation of motility which was significantly (p < 0.05) different when compared to the negative control. A significant (p < 0.05) IC50 of 0.18 mg/ml was recorded with GK when compared to KS (0.40 mg/ml), VA (0.25 mg/ml), and procaine penicillin (0.31 mg/ml). Mean packed cell volume, haemoglobin concentration, and mean corpuscular haemoglobin concentration decreased significantly (p < 0.05) in all infected groups and returned to almost pre-infection values. However, significant leucocytosis (p < 0.05) was observed in group II. AST and ALP showed a significant increase (p < 0.001). Histopathological evaluation showed the extracts to prevent the distortion of normal architecture of the selected organs.

CONCLUSION

This study demonstrates the significant potential of Garcinia kola, Khaya senegalensis, and Vernonia amygdalina extracts singly and in combination to combat leptospirosis.

In vivo and in silico antihypertensive, anti-inflammatory, and analgesic activities of Vernonia amygdalina Del. leaf extracts

Vernonia amygdalina (VA) leaves contain many potential active ingredients and exhibit diverse pharmacological activities. The antihypertensive, anti-inflammatory, and analgesic effects of VA crude and fraction extracts were carried out using Swiss albino mice models. VAE is considered safe to be administered due to LD50 being greater than 10,000 mg/kg body weight. A dose-dependent increase in antihypertensive, anti-inflammatory, and analgesic activities was observed in both VAE and fractions, similar to the reference drugs. The antihypertensive effect of the VAE 2.0 (2000 mg/kg, SBP: ↓26.05 %, DBP: ↓34.51 %) was nearly equivalent to Captopril (100 mg/kg, SBP: ↓30.28 %, DBP: ↓40.71 %) with no statistically significant difference (p > 0.05). The VAE 1.0 (1000 mg/kg), and EA 30 (30 mg/kg) showed potent anti-inflammatory activity when reducing the total edematous paw volume significantly (p < 0.01) by ↓65.58 %, and ↓69.34 %, respectively, similar to Ibuprofen (7.5 mg/kg, ↓67.03 %). Besides, VAE (>500 mg/kg), and W 400 (water, 400 mg/kg) fraction extracts showed a potent analgesic effect equivalent to Para 50 (paracetamol 50 mg/kg) for the highest protection (>65 %) against the acetic acid-induced writhing after 35 min. Moreover, cepharanthine, cynaroside, and vernoniosides of VA leaf extract exhibited the highest affinity (>10 kcal/mol) in anti-inflammatory and analgesic targets (iNOS and COX-2) and antihypertensive targets (ACE and β1 adrenoreceptor). Therefore, the crude and fraction extracts of VA leaves from the percolation method and bioactive metabolites are a potential source that can be developed into antihypertensive, anti-inflammatory, and analgesic agents in herbal medicine.

Identification of promising multi-targeting inhibitors of obesity from Vernonia amygdalina through computational analysis

Vernonia amygdalina, a widely consumed West African food herb, can be a boon in the discovery of safe anti-obesity agents given the extensive reports on its anti-obesity and antidiabetic potentials. The main aim of this study was to screen 78 Vernonia-Derived Phytocompounds (VDPs) against the active site regions of Human Pancreatic Lipase (HPL), Human Pancreatic Amylase and Human Glucosidase (HG) as drug targets associated with obesity in silico. Structure-based virtual screening helped to identify Luteolin 7-O-glucuronoside and Andrographidoid D2 as hit compounds with dual targeting tendency towards the HPL and HG. Analysis of the molecular dynamic simulation trajectory files of the ligand-receptor complexes as computed from the thermodynamic parameters plots showed not only increased flexibility and greater interaction potential of the active site residues of the receptor towards the VDPs as indicated by the root mean square fluctuation but also higher stability as indicated by the root mean square deviation, radius of gyration and number of hydrogen bonds. The cluster analysis further showed that the interactions with important residues were preserved in the dynamic environment. These observations were further verified from Molecular Mechanics Generalized Born Surface Area Analysis, which also showed that residual contributions to the binding free energies were mainly from catalytic residues at the active sites of the enzymes. The hit compounds also feature desirable physicochemical properties and drug-likeness. This study provides in silico evidence for the inhibitory potential of phytochemicals from Vernonia amygdalina against two target enzymes in obesity.

Bisabolane-type sesquiterpenes from Vernonia amygdalina: Absolute configuration and anti-inflammatory activity

The phytochemical assessment of Vernonia amygdalina resulted in the isolation and identification of seven undescribed bisabolane-type sesquiterpenes designated amygdanoids A-G and one known analogue. This is the first report of this type of sesquiterpene from V. amygdalina. Their structures, including the absolute configurations, were elucidated by comprehensive analysis with HRESIMS, 1D and 2D NMR, quantum chemical calculations of NMR and electronic circular dichroism (ECD), modified Mosher's method, and the in situ dimolybdenum CD method. The anti-inflammatory activity of the isolates was evaluated. All the isolated compounds clearly inhibited the production of NO and the expression of the iNOS protein. Secretion of the COX-2 protein was constrained by amygdanoids A-F. Further investigation suggested that amygdanoids E exhibited anti-inflammatory activity by suppressing the expression of iNOS and COX-2 as well as the PI3K/AKT/NF-κB signaling pathway.

FTO gene expression in diet-induced obesity is downregulated by Solanum fruit supplementation

The Fat Mass and Obesity-associated (FTO) gene has been shown to play an important role in developing obesity, manifesting in traits such as increased body mass index, increased waist-to-hip ratio, and the distribution of adipose tissues, which increases the susceptibility to various metabolic syndromes. In this study, we evaluated the impact of fruit-based diets of Solanum melongena (SMF) and Solanum aethiopicum fruits (SAF) on the FTO gene expression levels in a high-fat diet (HFD)-induced obese animals. Our results showed that the mRNA level of the FTO gene was downregulated in the hypothalamus, and white and brown adipose tissue following three and six weeks of treatment with SMF- and SAF-based diets in the HFD-induced obese animals. Additionally, the Solanum fruit supplementation exhibited a curative effect on obesity-associated abrasions on the white adipose tissue (WAT), hypothalamus, and liver. Our findings collectively suggest the anti-obesity potential of SMF and SAF via the downregulation of the FTO gene.

The anticancer activities of Vernonia amygdalina Delile. Leaves on 4T1 breast cancer cells through phosphoinositide 3-kinase (PI3K) pathway

Vernonia amygdalina Delile (Asteraceae) is used in traditional medicine to treat diabetes mellitus, and some research provides its activity to treat breast cancer. The aim of this study is to assess the anticancer activity of Vernonia amygdalina Delile leaves fractions on 4T1 breast cancer cells. Analysis of phytochemical compounds were carried out with LC-MS/MS. Cytotoxic activity was determined using the MTT method in the 4T1 cell line. Apoptosis, the cell cycle, and PI3K and mTOR profiles were analyzed with flow cytometry. The phytochemicals found were diterpene (ingenol-3-angelate) and some phenolics (chlorogenic acid and 4-methoxycinnamic acid), flavonoids (apigetrin, apigenin, luteolin, diosmetin, baicalin, rhoifolin, and scutellarin), and coumarines (7-hydroxycoumarine, 4-methylumbelliferone, and 4-methylumbelliferyl glucuronide). The results of the MTT assay showed that the IC₅₀ values n-hexane fraction, ethylacetate fraction (EAF), and ethanol fractions were 1,860.54 ± 93.11, 25.04 ± 0.36, and 1,940.84 ± 96.37 μg/mL, respectively. EAF induced early and late apoptosis, inhibited cell cycle progression on the G₂/M phase, and inhibited PI3K and mTOR expression. The EAF of Vernonia amygdalina Delile leaves showed anticancer activity on 4T1 breast cancer cells through induction of apoptosis, enhanced cell accumulation on G₂/M phases in the cell cycle, and inhibited expression of PI3K and mTOR.

Cell Cycle Inhibition and Apoptotic Induction of Vernonia amygdalina Del. Leaves Extract on MCF-7 Cell Line

AIM:

The research aimed to determine the cytotoxic activity, cell cycle inhibition, and apoptosis induction of the ethyl acetate extract of the African leaves Vernonia amygdalina Del. on the MCF-7 cancer cells.

METHODS:

The extraction of Vernonia amygdalina Del. leaves was done using the maceration method whereas the cytotoxic was performed using MTT assay. After that, the cell cycle testing and apoptosis induction were conducted using flow cytometry assay.

RESULTS:

The IC₅₀ values of n-hexane, ethyl acetate, and ethanol extract of Vernonia amygdalina Del. on the MCF-7 cancer cells were 206.211 ± 0.99, 50,365 ± 0.07, and 967.033 ± 2.68 µg/mL, respectively. The percentage of the cycle cell results in the G₀-G₁ phase in the cell control with 72.08% decreased in the treatment with ethyl acetate extract 1/2 IC₅₀ with 62.58% and 1/5 IC₅₀ with 44.72%. For the S and G2-M phase, the highest percentage was found in the ethyl acetate extract 1/5 IC₅₀ treatment with 47.27% and 9.50% which were higher than the control cells with 23.26% and 5.90%.

CONCLUSION:

Based on the results, the Vernonia amygdalina Del. extract provides chemopreventive agent as anti-cancer. Our future study will assess the mechanism of ethyl acetate fraction in inhibiting angiogenesis and metastatic in breast cancer.

African Walnuts (Tetracarpidium conophorum) Modulate Hepatic Lipid Accumulation in Obesity via Reciprocal Actions on HMG-CoA Reductase and Paraoxonase

BACKGROUND

Obesity is characterized by increased body fat and involves an imbalance between the synthesis and degradation of lipids.

OBJECTIVE

The study aimed to investigate the effect of African walnuts (Tetracarpidium conophorum) on lipids storage and the regulatory enzymes of hepatic lipid metabolism in obese rats.

METHODS

Nuts were extracted in ethanol (WE) and further separated to obtain the ethyl-acetate fraction (ET) and the residue (RES). These were administered orally to 3 groups of monosodium glutamate- obese rats (n = 6), respectively, for 6 weeks. Other groups in the study were: normal (NC), obese control (OC) and standard control (SC) which received orlistat. Hepatic total lipids, total phospholipids, triacylglycerol (TG), total cholesterol (TCHOL), 3-hydroxyl-3-methylglutaryl-CoA (HMG-CoA) reductase and paraoxonase were studied.

RESULTS

Total lipids, TG and TCHOL which increased in OC compared to NC group, decreased. HMG-CoA reductase activity decreased in the 3 study groups relative to OC. Paraoxonase activity which decreased in OC was up-regulated, while the magnitude of hepatic cholesterol decreased from 94.32 % in OC to 52.19, 65.43 and 47.04 % with WE, ET and RES, respectively. Flavonoids, alkaloids, glycosides, tannins and saponins were detected in the nut. GC-MS analysis revealed 16, 18 and 10 volatile components in WE, ET and RES, respectively. Unsaturated fatty acids (linolenic acids: 33.33, 47.95 and 50.93 %, and α-linolenic acids: 25, 19.66 and 26.63 %) in WE, ET and RES, respectively, are the most abundant, and likely to be responsible for the observed activity.

CONCLUSION

African walnuts can prevent hepatic lipid accumulation through reciprocal actions on HMG-CoA reductase and paraoxonase in obesity.

Salvia hispanica L. (chia) seeds oil extracts reduce lipid accumulation and produce stress resistance in Caenorhabditis elegans

Background

Salvia hispanica seeds have been commonly used by people that seek healthy habits through natural foods to reduce cholesterol and triacylglycerides levels, however, the evidences that support this assumption are still scarce in literature. Here, we aimed to evaluate the lipid lowering effects of chia by using Caenorhabditis elegans as animal model, a nematode that has proven its usefulness for lipid metabolism studies.

Methods

We prepared hexane (HE) and Bligh-Dyer (BDE) extracts, evaluated and compared their safety, antioxidant potential and their lipid-lowering activity in the worms.

Results

The characterization of both extracts demonstrated that there were no differences in their lipid composition; however, BDE depicted better antioxidant potential. Both extracts reduced worm’s survival from 2%, and reproduction was reduced following treatment with both extracts, though a more notable effect was observed in HE-treated worms. In addition, the non-toxic concentration of both extracts (1%) increased stress resistance against paraquat toxicity in an antidote paradigm. Notably, this same concentration of both extracts reduced lipid accumulation in obese worms, which was not caused by food deprivation.

Conclusions

Taken together, our data demonstrate that both extraction methods from chia seeds result in oils that are rich in mono and polyunsaturated fatty acids, which may modulate lipid accumulation and provide antioxidant resistance in C. elegans.

Steroidal Saponins from Vernonia amygdalina Del. and Their Biological Activity

In the present study, four new steroidal saponins, namely vernoniamyoside A–D (1–4), together with the two known steroidal saponins vernoamyoside D (5) and vernonioside B₂ (6) were isolated from the ethanol extract of leaves of the African medicinal plant Vernonia amygdalina Del. (Asteraceae). Their structures were demonstrated by spectral analyses along with 1D and 2D nuclear magnetic resonance (NMR) techniques and mass spectrometry (MS). The cytotoxicity of the compounds was also tested by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method on the cell lines Hela, MCF-7, BT-549 and MDA-MB-231. Vernoniamyoside A, vernoniamyoside B, and vernonioside B₂ showed cytotoxicity towards BT-549 cell lines. Vernoniamyoside C, vernoniamyoside D and vernoamyoside D showed different levels of cytotoxic activities.

Vasorelaxant properties of Vernonia amygdalina ethanol extract and its possible mechanism

CONTEXT

Vernonia amygdalina Del. (VA) (Asteraceae) is commonly used to treat hypertension in Malaysia.

OBJECTIVE

This study investigates the vasorelaxant mechanism of VA ethanol extract (VAE) and analyzes its tri-step FTIR spectroscopy fingerprint.

MATERIALS AND METHODS

Dried VA leaves were extracted with ethanol through maceration and concentrated using rotary evaporator before freeze-dried. The vasorelaxant activity and the underlying mechanisms of VAE using the cumulative concentration (0.01-2.55 mg/mL at 20-min intervals) were evaluated on aortic rings isolated from Sprague Dawley rats in the presence of antagonists.

RESULTS

The tri-step FTIR spectroscopy showed that VAE contains alkaloids, flavonoids, and saponins. VAE caused the relaxation of pre-contracted aortic rings in the presence and absence of endothelium with EC₅₀ of 0.057 ± 0.006 and 0.430 ± 0.196 mg/mL, respectively. In the presence of Nω-nitro-l-arginine methyl ester (EC₅₀ 0.971 ± 0.459 mg/mL), methylene blue (EC₅₀ 1.203 ± 0.426 mg/mL), indomethacin (EC₅₀ 2.128 ± 1.218 mg/mL), atropine (EC₅₀ 0.470 ± 0.325 mg/mL), and propranolol (EC₅₀ 0.314 ± 0.032 mg/mL), relaxation stimulated by VAE was significantly reduced. VAE acted on potassium channels, with its vasorelaxation effects significantly reduced by tetraethylammonium, 4-aminopyridine, barium chloride, and glibenclamide (EC₅₀ 0.548 ± 0.184, 0.158 ± 0.012, 0.847 ± 0.342, and 0.304 ± 0.075 mg/mL, respectively). VAE was also found to be active in reducing Ca²⁺ released from the sarcoplasmic reticulum and blocking calcium channels.

CONCLUSIONS

The vasorelaxation effect of VAE involves upregulation of NO/cGMP and PGI₂ signalling pathways, and modulation of calcium/potassium channels, and muscarinic and β₂-adrenergic receptor levels.

Effect of aqueous extract of Vernonia amygdalina on atherosclerosis in rabbits

BACKGROUND

Extracts of Vernonia amygdalina (V. amygdalina) have been shown to affect the serum lipid profile of some laboratory animals in previous studies. Its impact on serum lipid profile and the histological changes in atherosclerosis has not been studied. Our aim was to determine the effects of V. amygdalina on atherosclerotic lesions induced in rabbits on high-cholesterol diet.

METHODS

18 male rabbits were randomly divided into three groups of control, atherogenic diet, and atherogenic diet + 200 mg/kg of V. amygdalina. The rabbits were fed a normal diet (control group) or a diet supplemented by 0.5% cholesterol and 1% methionine (second and third groups, respectively) for 12 weeks. The fasting sera of all animals were collected at baseline and at the end of the 12 weeks, to determine the levels of lipid profile and the aortas underwent pathomorphological examination.

RESULTS

The two groups on the atherogenic diet had significantly increased serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) compared to the control group. The serum triglyceride (TG) was not statistically different in all three groups. High-density lipoprotein cholesterol (HDL-C) was significantly increased in the V. amygdalina group, compared to the control group but there was no statistically significant difference between the two groups on atherogenic diet. The two groups of rabbits that were on high-cholesterol diet (atherogenic diet group, as well as the atherogenic diet + 200 mg/kg of V. amygdalina) developed histological evidence of atherosclerosis. However, there was no histological difference between the lesions observed in these two groups.

CONCLUSION

The use of 200 mg/kg of aqueous extract of V. amygdalina in rabbits did not appear to exert a significant effect on the serum lipid profile. It also did not appear to have any beneficial effect on the development of atherosclerotic lesions.

Anti-obesity Effect of Dioscorea oppositifolia Extract in High-Fat Diet-Induced Obese Mice and Its Chemical Characterization

Dioscorea oppositifolia is a well-known edible and traditional medicine for the treatment of gastrointestinal diseases. In our previous study, D. oppositifolia exhibited both pancreatic lipase inhibition and an anti-adipogenesis effect in vitro. This study was performed to investigate the anti-obesity effect of D. oppositifolia on high-fat diet-induced obese mice. Female ICR mice were fed a high-fat diet with the 100 mg/kg of D. oppositifolia n-BuOH extract for 8 weeks. The high-fat diet mice received the 15 mg/kg Orlistat orally as a positive control. The body weight, parametrial adipose tissue weight, and the levels of triglyceride (TG), total cholesterol (TC), and low density lipoprotein (LDL)-cholesterol in blood serum of female ICR mice were significantly decreased by feeding a high-fat diet with the n-BuOH extract of D. oppositifolia. An inhibitory effect of D. oppositifolia extract on dietary fat absorption was also clearly shown. The D. oppositifolia sample was found to contain 3,5-dimethoxy-2,7-phenanthrenediol and (3R,5R)-3,5-dihydroxy-1,7-bis(4-hydroxyphenyl)-3,5-heptanediol as main components based on its phytochemical analysis. The present study is the first report of the anti-obesity effect by D. oppositifolia n-BuOH extract using an established disease model. The increase in fecal fat excretion by treatment of D. oppositifolia may be an effective approach for treating obesity and related diseases.