Lead finding from medicinal plants with hepatoprotective potentials

Potential Efficacy of β-Amyrin Targeting Mycobacterial Universal Stress Protein by In Vitro and In Silico Approach

The emergence of drug resistance and the limited number of approved antitubercular drugs prompted identification and development of new antitubercular compounds to cure Tuberculosis (TB). In this work, an attempt was made to identify potential natural compounds that target mycobacterial proteins. Three plant extracts (A. aspera, C. gigantea and C. procera) were investigated. The ethyl acetate fraction of the aerial part of A. aspera and the flower ash of C. gigantea were found to be effective against M. tuberculosis H₃₇Rv. Furthermore, the GC-MS analysis of the plant fractions confirmed the presence of active compounds in the extracts. The Mycobacterium target proteins, i.e., available PDB dataset proteins and proteins classified in virulence, detoxification, and adaptation, were investigated. A total of ten target proteins were shortlisted for further study, identified as follows: BpoC, RipA, MazF4, RipD, TB15.3, VapC15, VapC20, VapC21, TB31.7, and MazF9. Molecular docking studies showed that β-amyrin interacted with most of these proteins and its highest binding affinity was observed with Mycobacterium Rv1636 (TB15.3) protein. The stability of the protein-ligand complex was assessed by molecular dynamic simulation, which confirmed that β-amyrin most firmly interacted with Rv1636 protein. Rv1636 is a universal stress protein, which regulates Mycobacterium growth in different stress conditions and, thus, targeting Rv1636 makes M. tuberculosis vulnerable to host-derived stress conditions.

Alterations of haemato-biochemical parameters pre and post-challenge with Aeromonas hydrophila and survival of Oreochromis mossambicus fed Moringa oleifera-based diets

This study investigated the extent of changes in haemato-biochemical and immunological parameters of O. mossambicus fed with M. oleifera-based diets pre and post-challenge with different concentrations of A. hydrophila. Moringa oleifera powdered leaves were added to five experimental diets at 0%, 3%, 6%, 9% and 12%, designated D1, D2, D3, D4 and D5, respectively. Each diet was randomly fed to triplicate groups of 45 fish (33.46 ± 1.57 g) for 45 days. There were no significant differences (P > 0.05) in WG, FCR and SGR between treatments. There was an increase in WBC, RBC, HGB and HCT with increasing M. oleifera levels. No significant changes (P > 0.05) were observed in AST, ALT, ALP and LDH levels between treatments. After 45 days, fish from each treatment were injected with varying concentrations (0, 1 × 10⁶ cfu, 1.5 × 10⁶ cfu, 3 × 10⁶ cfu and 4 × 10⁶ cfu ml^-1) of Aeromonas hydrophila. There was a significant decline in RBC, HGB and HCT of fish in the D1-D3 compared to the D4 and D5 groups. There was an increase in AST, ALT, ALP and LDH in the D1-D3 groups while no significant changes (P > 0.05) were observed in the D4 and D5 groups between bacterial concentrations. Survival rate was lower in the D1-D3 compared to the D4 and D5 groups, indicating that immunity was enhanced in fish fed with the highest M. oleifera inclusion levels. NBT and lysozyme activities were also lower in the D1-D3 groups compared to the D4 and D5 groups. The enhancement of immunity is attributed to the presence of biologically active compounds with immunostimulatory properties. The phytochemistry of the M. oleifera revealed high levels of total polyphenol, total phenols, total flavonoids, carotenoids, vitamins C and E.

Hepatoprotective properties of extensively studied medicinal plant active constituents: possible common mechanisms

CONTEXT

We focused on certain plant active constituents considered to be the most promising/studied for liver disease and that were critically investigated from the basic science point of view and, to some extent, the clinical one. Due to insufficient pharmacological data, most of the herbal formulations containing these molecules cannot be recommended for the treatment of liver disease.

OBJECTIVE

To present the most promising compounds tested experimentally and/or clinically and describe in brief popular models in experimental testing of potential hepatoprotective compounds.

METHODS

A literature search using Web of Science (WOS), PubMed, and Google search was performed.

RESULTS

Focusing on a few herbal hepatoprotective active constituents is useful to health professionals working in the field of therapeutics to develop evidence-based hepatoprotective agents by conducting research on pure chemical structures or on molecular modifications using computational chemistry. This review demonstrates that multi-pathways in the liver pathobiology can be interrupted at one or more levels by natural hepatoprotective studied, such as interference with the oxidative stress at multiple levels to reduce reactive oxygen/nitrogen species, resulting in ameliorating hepatotoxicity.

CONCLUSION

Hepatoprotective constituents of herbal medications are poorly absorbed after oral administration; methods that can improve their bioavailability are being developed. It is recommended that controlled prospective double-blind multicenter studies on isolated active plant constituents, or on related newly designed molecules after structural modifications, should be performed. This effort will lead to expanding the existing, limited drugs for the vast majority of liver diseases.

Investigation of hepatoprotective activity of Cyathea gigantea (Wall. ex. Hook.) leaves against paracetamol-induced hepatotoxicity in rats

OBJECTIVE

To investigate the hepatoprotective activity of methanolic leaf extract of Cyathea gigantea (C. gigantea) against paracetamol induced liver damage in rats.

METHODS

The hepatoprotective activity for plant extract was investigated for paracetamol induced hepatoxicity in rats. Wistar albino rats of either sex were divided into five groups of 6 animals each and are given orally the following treatment for seven days. The normal control group was given 1% Na.CMC 1 mL/kg bw, p.o. Paracetamol at dose of 1 g/kg bw, p.o. was given as toxic dose for inducing hepatotoxicity. Silymarin (50 mg/kg, p.o.) was given as reference standard. Two doses of C. gigantea extract i.e., 100 mg/kg, p.o. and 200 mg/kg, p.o. were tested for hepatoprotective activity. The treatment was given for seven days and after 24 h of last treatment blood was collected from retro-orbital plexus and analysed for various serum parameters like serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), total bilirubin (TB) and total protein (TP) in different groups.

RESULTS

The paracetamol intoxication lead to histological and biochemical deteriorations. The treatment with methanolic leaf extract of C. gigantea reduced the elevated levels of SGOT, SGPT, ALP, TB and also reversed the hepatic damage towards normal which further supports the hepatoprotective activity of leaf extract of C. gigantea.

CONCLUSIONS

The methanolic extract of leaves of C. gigantea at doses of 100 mg/kg bw and 200 mg/kg bw have significant effect on liver of paracetamol induced hepatotoxicity model in rats.

Immunostimulatory effect of artificial feed supplemented with indigenous plants on Clarias gariepinus against Aeromonas hydrophila

The antibacterial activity of methanol extracts of Ficus benghalensis (prop-root) and Leucaena leucocephala (pod seed) was evaluated by measurement of zone of inhibition against pathogenic bacteria, Escherichia coli and Aeromonas hydrophila. Control artificial feed and artificial feed supplemented with 5% powder of F. benghalensis and L. leucocephala were prepared. Juvenile Clarias gariepinus were divided into four groups, acclimatized to laboratory conditions and fed with respective feeds for 20 days prior to the experiment. Immunomodulatory response of supplementary feed was studied by challenging the fish intraperitoneally at weekly intervals, with A. hydrophila. One set of fish, not challenged with A. hydrophila was used as a negative control, to analyze any detrimental effect of supplementary feed, while positive control, comprised of challenged fish fed with non-supplemented feed. Other two groups of fish were challenged with A. hydrophila and fed with respective supplementary feeds. Blood was collected on weekly intervals for four weeks and serum samples were analyzed to evaluate the damage of fish by A. hydrophila through liver function tests. The increase in the levels of Serum glutamic oxaloacetic transaminase (SGOT) and Serum Glutamic pyruvate transaminase (SGPT) in positive control group indicated the damage of liver & kidney. However the levels did not change significantly in fish fed with supplementary feeds when compared to negative control group. Nitric oxide, SOD, ALP and lipid peroxidase indicated lower stress levels in these fish compared to positive control. Fish fed with supplementary feed showed increased lysozyme activity and phagocytic index indicating an increase in non-specific immune response. The immunoglobulin levels of in serum were analyzed by homologous sandwich ELISA, which showed higher antibody production in fish fed with supplementary feed. The current study suggests conclusively, immunostimulatory role of F. benghalensis (prop-roots) and L. leucocephala (pod seed) in C. gariepinus when supplemented in artificial feed.

Traditional phytotherapy remedies used in Southern Rwanda for the treatment of liver diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Liver diseases represent a major health problem due to their complications and limited treatment possibilities. In Rwanda, given low accessibility to modern treatments, most people still rely on traditional medicinal plants. The symptomatology of many hepatic troubles (icterus) is evident for traditional healers who have a high probability of selecting efficient herbal medicines.

OBJECTIVES

To document medicines used in the treatment of "hepatitis" in Southern Rwanda with the knowledge, attitudes and practices related to liver disorder recognition, control and treatment.

MATERIALS AND METHODS

56 traditional health practitioners, each a legal representative of an official association, were interviewed and participated in plant collection for the preparation of botanically identified herbarium specimens.

RESULTS

68 multi-component and 65 single-component herbal recipes were identified for the treatment of liver diseases with a total of 86 different herbs from 34 families identified. The most represented were the Asteraceae and the Lamiaceae. Crassocephalum vitellinum, Hypoestes triflora and Erythrina abyssinica were the most widely used plants. The principle of polymedication for complex (i.e. multifactorial) diseases ("Ifumbi" in Rwanda), is a constant in every traditional practice. It is striking that the Rwandese therapy of liver diseases proposes so many single-herb preparations (49% of all herbal preparations). Some of the recorded plants or other species from the same genus have previously been documented for liver protection using various in vivo and in vitro models.

CONCLUSION

Herbal remedies for hepatitis are widely used and highly diverse in Southern Rwanda; further chemical, pharmacological and toxicological studies are clearly required to rationally develop the most important remedies.

Ethnopharmacology and integrative medicine - Let the history tell the future

Traditional systems of medicines need more evidence-based studies on both crude drugs and purified phytomolecules. Utilization of natural products as pharmacological tools could lead to a number of new major therapeutically active metabolites. Lead molecules are further screened for their potential in terms of quality control, safety assessments, and studies about molecular pharmacology and their related properties. Identification, and quality and safety evaluation of natural products, is a fundamental requirement of industry and other organizations dealing with natural health products (NHPs). Marker analysis, based on chemo-profiling and development of characteristic fingerprints for individual plants, could help to develop uniform standardization tools. Beside such evaluations of clinical parameters, safety profiles as well as drug-herb and herb-herb interactions are the most important parameters for assessment and promotion. With the steady growth of the NHPs, advanced analytical- and mechanism-based screening should be considered for their promotion and value addition in every way for the betterment of healthcare. Thus, there is an urgent need for the development of international co-ordination to promote and develop NHPs, including their assessment, perspectives, pharmacovigilance, and potential harmonization of regulation, quality control and clinical uses.

Extraction and phytochemical investigation of Calotropis procera: effect of plant extracts on the activity of diverse muscles

CONTEXT

Calotropis procera (Ait.) R.Br. (Asclepiadaceae) is a shrub or small tree that grows wild in Egypt. Calotropis acts as a purgative, anthelmintic, anticoagulant, palliative (in problems with respiration, blood pressure), antipyretic, and analgesic, and induces neuromuscular blocking activity. Little research has been done to study the electrophysiological effects of this plant's extracts on cardiac, smooth, and skeletal muscle activities.

OBJECTIVE

The present study was conducted to determine the phytochemical composition and the effect of the total alcohol extract of the shoot of the plant, which contains almost all of C. procera's cardiac glycosides, flavonoids, and saponins. Also, this study attempted to throw more light on the electrophysiological effects of the plant extracts on cardiac, smooth, and skeletal muscle activities and to clarify the mechanism(s) of their observed action(s).

MATERIALS AND METHODS

The aerial parts of the plant were air dried and their ethanol extracts partitioned with successive solvents. Cardiac, smooth, and skeletal muscles were used in this study to investigate the physiological and pharmacological effects of the plant extracts from different solvents. The data were analyzed by paired t-test.

RESULTS

The phytochemical investigation of Calotropis procera revealed the presence of cardenolides, flavonoids, and saponins. The effects of ethanol, n-butanol, and ethyl acetate (EtOAc) extracts were each evaluated on isolated toad heart and their mechanisms of action determined. Perfusion with 2 μg/mL ethanol, 0.2 μg/mL butanol, and 0.2 μg/mL EtOAc extracts caused a significant decrease in heart rate (bradycardia), significant increase in the force of ventricular contraction, and increase in T-wave amplitude. In addition, the effects of different extracts of the studied plant on smooth muscle and skeletal muscle were investigated in this study. The different extracts and latex of C. procera induced a negative chronotropic effect and decreased the heart rate (HR) of isolated toad heart. The different extracts increased the power of contraction of the duodenum (trace a). Pretreatment with atropine sulfate as a muscarinic receptor blocker abolished the stimulatory effect of the different plant extracts and latex of C. procera (trace b).

DISCUSSION

The present data suggest that ethanol, butanol, and EtOAc extracts of Calotropis procera have negative chronotropism and positive inotropism. Verapamil could abolish the inotropic effect of ethanol as well as that of butanol and EtOAc extracts. Meanwhile, atropine did not abolish the observed negative chronotropic effect. The ethanol extract increased the power of contraction of rabbit duodenum, but atropine abolished this effect. It also decreased the skeletal muscle contraction; this effect could be through blocking of the nicotinic receptors. Butanol and EtOAc extract data for smooth and skeletal muscles are very close to those for the corresponding ethanol extract of the studied plant. The present data for C. procera indicate its direct action on the myocardium, its increase of smooth muscle motility, and its relaxation of skeletal muscle contraction. The chemical constituents could directly affect the cell membrane probably through receptors coupling to G proteins. They regulate the ion channel physiology as in the myocardium.

CONCLUSION

The present data on the extracts of C. procera indicate a direct action on the myocardium, stimulatory effect on smooth muscle motility, and relaxant action on skeletal muscle contraction. Chemical constituents could directly affect the cell membrane probably through receptors coupling to G proteins. They regulate the ion channel physiology as in the myocardium.