Protorhus Longifolia Research Articles

Two Triterpenoids, ARM-2 and RA-5, From Protorhus longifolia Exhibit the Potential to Modulate Lipolysis and Lipogenesis in Cultured 3T3-L1 Adipocytes.

Triterpenoids have been identified as potential novel lipid-lowering drugs for the treatment of hypertriglyceridemia. This study investigated the potential antilipogenic and/or antilipolytic effects of two triterpenoids (ARM-2 and RA-5) isolated from the stem bark of Protorhus longifolia (Benrh.) Engl. Employing a combination of in silico predictions and in vitro assays, the interactions between these triterpenoids and key proteins involved in lipogenesis and lipolysis were investigated. In silico molecular docking analysis predicted a favourable binding affinity of both triterpenoids to PPARγ, SREBP-1, and AMPK, with lower binding affinity to C/EBPα, pancreatic lipase, and hormone-sensitive lipase (HSL). Both triterpenoids exhibited in vitro inhibition of pancreatic lipase with Ki and IC50 values ranging from 28.7 to 52.9 μM and 27.6 to 35.8 μM, respectively. Total and neutral lipid accumulation in differentiated 3T3-L1 adipocytes and the oleic acid-induced HepG2 cell model was inhibited, with ARM-2 showing better inhibition than RA-5. In the HepG2 model, the inhibitory activity of the two triterpenoids (at 25 and 100 μM) was comparable to 50 μM lovastatin, although the latter was cytotoxic, whereas both ARM-2 and RA-2 lacked cytotoxicity. Associated gene expression was similar to the effect of simvastatin where the expression of SREBP-1, PPARγ, C/EBPα, and HSL was reduced and that of AMPK was unchanged. In vitro studies confirmed that ARM-2 and RA-5 also inhibited adipocyte lipolysis, where the reduction in glycerol release by 25 and 100 μM was similar to 50 μM lovastatin and simvastatin. This study identifies that the triterpenoids, ARM-2 and RA-5, have the potential to modulate lipogenesis and lipolysis.

Triterpenoids from Protorhus longifolia Exhibit Hypocholesterolemic Potential via Regulation of Cholesterol Biosynthesis and Stimulation of Low-Density Lipoprotein Uptake in HepG2 Cells.

The increasing incidence of hypercholesterolemia-related diseases even in the presence of the currently available cholesterol-lowering drugs indicates a need to discover new therapeutic drugs. This study aimed to investigate the hypocholesterolemic potential of two triterpenoids isolated from Protorhus longifolia stem bark. In silico techniques and in vitro enzyme assays were used to evaluate the potential inhibition of cholesterol esterase and HMG-CoA reductase by the triterpenoids (ARM-2 and RA-5). The toxicity, modulation of low-density lipoprotein (LDL) uptake, and associated gene expression were determined in HepG2 hepatocytes. In silico molecular docking revealed that ARM-2 compared with RA-5 has a relatively stronger binding affinity for both enzymes. Both triterpenoids further demonstrated promising in silico drug-likeness properties and favorable ADMET profiles characterized by high intestinal absorption and lack of CYP450 enzyme inhibition. The compounds further showed, to varying degrees of efficacy, inhibition of cholesterol micellization as well as both cholesterol esterase and HMG-CoA reductase activities with IC50 values ranging from 16.4 to 41.1 μM. Moreover, enhanced hepatic cellular LDL uptake and the associated upregulation of the LDL-R and SREBP-2 gene expression were observed in the triterpenoid-treated HepG2 cells. It is evident that the triterpenoids, especially ARM-2, possess hypocholesterolemic properties, and these molecules can serve as leads or structural templates for the development of new hypocholesterolemic drugs.

In vitro antibacterial activity of Loxostylis alata extracts and isolated compounds against Salmonella species

BackgroundOwing to antibiotic resistance, alternative antimicrobials from medicinal plants are receiving attention as leads for anti-infective agents. This study aimed to investigate selected tree species and their constituents for activity against bacterial foodborne pathogens, particularly Salmonella serovars.MethodsAntibacterial activity of ten plant species was determined by serial microdilution against bacteria implicated in causing gastrointestinal ailments. Active compounds were isolated from Loxostylis alata using bioassay-guided fractionation. Antioxidant activity was determined using free-radical scavenging assays. Cytotoxicity and genotoxicity of the extracts was ascertained on Vero cells, and using the Ames assay respectively.ResultsExtracts had low to moderate MIC values from 0.04 to 2.5 mg/mL. Protorhus longifolia and Loxostylis alata were most active and L. alata had the highest selectivity index value (2.51) against Salmonella Typhimurium, as well as high antioxidant activity. Cytotoxicity values ranged from 0.02 to 0.47 mg/mL, while tested extracts were not genotoxic. Bioactive compounds isolated from L. alata included delicaflavone and a polymethoxyflavone.ConclusionsThe Loxostylis alata leaf extract had strong activity against Salmonella serovars but isolated compounds were less active, indicating likely synergistic effects. Extracts of L. alata are promising candidates for development of antimicrobial preparations or food additives against microbial contamination.

Insight Into The Molecular Basis Of The Anti‑Hyperglycemic Activity Of Ra‑3 In Type 2 Diabetic Rats And Its Cardioprotective Potential In Cultured Cardiomyoblasts

Insulin resistance, a hallmark of type 2 diabetes mellitus (T2DM), is the underlying cause of various metabolic changes observed in type 2 diabetic patients. This study investigated the molecular basis of the anti-hyperglycemic activity of RA-3, the lanosteryl triterpene from Protorhus longifolia, in type 2 diabetic rats and its cardioprotective potential in cultured cardiomyoblasts. To mimic a hyperglycemic state, H9c2 cells were exposed to high glucose concentration (33 mM) for 24 hours. Thereafter, the cells wells were treated with RA3 (1 μM). The high-fat diet fed (HFD) and STZ-induced T2DM in rat model was used to evaluate the anti-hyperglycemic activity of RA-3. The T2DM mimetic rats were orally administered with RA-3 (100 mg/kg) daily for 28 days. Blood and skeletal muscles were collected for biochemical and protein (IRS-1, AKT, GSK and GLUT 4) expression analysis. Biochemical analysis of the cell extracts revealed that RA3 improves glucose uptake via insulin- dependent (IRS-1/PI3K/Akt signaling) and independent (AMPK) pathways whilst ameliorating the activity of antioxidant enzymes defense in the H9c2 cells. The in vivo results showed significant decrease in p-GSK-3β and p-AKT expression, whereas the expression of IRS- 1ser307 were increased when compared to the model control group. This effect was ablated upon treatment of the animals with RA-3 and this was concomitant to an observed increase in GLUT 4 expression. It was concluded that the anti-hyperglycemic effect of RA-3 could partly be associated with its ability to improve cellular glucose uptake in muscle tissue and thus alleviating hyperglycemia- induced tissue damage.

Enhanced Antioxidant Efficacy of Nano-Encapsulated Protorhus Longifolia Methanol Extract Stabilized with Eudragit

This study describes the synthesis of Protorhus longifolia methanolic leaf extract-loaded Eudragit nanoparticles (NPs) and assessment of their antioxidant activity comparative to the free methanolic extract. The latter was also analyzed for its total phenolic content (TPC) and total flavonoid content (TFC). The extract-loaded NPs were obtained through the emulsification solvent evaporation process and systematically characterized using the dynamic light scattering, entrapment efficiency, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The antioxidant power was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing ability of plasma (FRAP) in vitro model systems. Screening of the different classes of secondary metabolites was carried out through chemical reaction tests. Identification of the potential antioxidants was performed using the gas chromatography-mass spectrometry (GC-MS) technique and the database of National Institute Standard and Technology (NIST). The characterization techniques showed spherical-like particles having an average size of 150[Formula: see text]nm and zeta potential of [Formula: see text]22[Formula: see text]mV. The percentage of entrapped methanolic extract was determined to be 83%. The antioxidant assay demonstrated that this methodology persuaded an efficient concentration-dependent potential. This study indicates that nanoformulation of the Protorhus longifolia extracts leads to a suitable system for the enhancement of antioxidant activity. The appraisal of other pharmacological activities of the nano-encapsulated Protorhus longifolia methanol extract is under process.

Molecular basis of the anti-hyperglycemic activity of RA-3 in hyperlipidemic and streptozotocin-induced type 2 diabetes in rats

BackgroundInsulin resistance is a hallmark of type 2 diabetes mellitus (T2DM) and the underlying cause of various metabolic changes observed in type 2 diabetic patients. This study investigated the molecular basis of the anti-hyperglycemic activity of the lanosteryl triterpene (RA-3), from Protorhus longifolia stem bark, in hyperlipidemic and streptozotocin (STZ)-induced T2DM in rats.MethodsThe high-fat diet fed (HFD) and STZ-induced T2DM in rat model was used to evaluate the anti-hyperglycemic activity of RA-3. The hyperlipidemic rats received a single intraperitoneal injection of STZ (35 mg/kg body weight) to induce T2DM. The experimental animals received a daily oral single dose of RA-3 (100 mg/kg body) for a period of 28 days, whiles the control group received distilled water only. The animals were euthanized, and skeletal muscle was collected for protein (IRS-1, AKT, GSK and GLUT 4) expression analysis. Western blot confirmed expression of the proteins.ResultsTreatment of the diabetic animals with the RA-3 showed marked reduction in fasting plasma glucose levels in comparison to the untreated diabetic group animals. A significant decrease in p-GSK-3β and p-AKT expression was observed, whereas the expression of IRS-1ser307 were increased when compared to the diabetic control group. This effect was ablated upon treatment with RA-3 and this was concomitant to an observed increase in GLUT 4 expression.ConclusionsThe results obtained in the present study strongly suggested that the anti-hyperglycemic effect of RA-3 could partly be associated with its ability to improve cellular glucose uptake in muscle tissue from T2DM.

A Lanosteryl triterpene from Protorhus longifolia augments insulin signaling in type 1 diabetic rats

BackgroundA substantial literature supports antidiabetic properties of the lanosteryl triterpene (methyl-3β-hydroxylanosta-9,24-dien-21-oate, RA-3) isolated from Protorhus longifolia stem bark. However, the molecular mechanism(s) associated with the antihyperglycemic properties of the triterpene remained to be explored. The current study aimed at investigating the molecular mechanism(s) through which RA-3 improves insulin signaling in streptozotocin-induced type 1 diabetic rats.MethodsThe type 1 diabetic rats were treated daily with a single oral dose of RA-3 (100 mg/kg) for 28 days. The rats were then sacrificed, and blood, skeletal muscle and pancreases were collected for biochemical, protein expression and histological analysis, respectively.ResultsPersistently high blood glucose levels in the diabetic control rats significantly increased expression of IRS-1Ser307 while the expression of p-Akt Ser473, p-GSK-3β Ser9, GLUT 4 and GLUT 2 were decreased. However, enhanced muscle insulin sensitivity, which was indicated by a decrease in the expression of IRS-1ser307 with a concomitant increase in the p-AktSer473, p-GSK-3β Ser9, GLUT 4 and GLUT 2 expression were observed in the diabetic rats treated with RA-3. The triterpene-treated animals also showed an improved pancreatic β-cells morphology, along with increased C-peptide levels. An increase in the levels of serum antioxidants such as catalase, superoxide dismutase, and reduced glutathione was noted in the rats treated with the triterpene, while their serum levels of interleukin-6 and malondialdehyde were reduced.ConclusionsIt is apparent that RA-3 is able to improve the insulin signaling in type 1 diabetic rats. Its beta (β)-cells protecting mechanism could be attributed to its ability to alleviate inflammation and oxidative stress in the cells.

Lanosteryl triterpenes from Protorhus longifolia as a cardioprotective agent: a mini review.

The epidemic of cardiovascular diseases is a global phenomenon that is exaggerated by the growing prevalence of diabetes mellitus. Coronary artery disease and diabetic cardiomyopathy are the major cardiovascular complications responsible for exacerbated myocardial infarction in diabetic individuals. Increasing research has identified hyperglycemia and hyperlipidemia as key factors driving the augmentation of oxidative stress and a pro-inflammatory response that usually results in increased fibrosis and reduced cardiac efficiency. While current antidiabetic agents remain active in attenuating diabetes-associated complications, overtime, their efficacy proves limited in protecting the hearts of diabetic individuals. This has led to a considerable increase in the number of natural products that are screened for their antidiabetic and cardioprotective properties. These natural products may present essential ameliorative properties relevant to their use as a monotherapy or as an adjunct to current drug agents in combating diabetes and its associated cardiovascular complications. Recent findings have suggested that triterpenes isolated from Protorhus longifolia (Benrh.) Engl., a plant species endemic to Southern Africa, display strong antioxidant and antidiabetic properties that may potentially protect against diabetes-induced cardiovascular complications. Thus, in addition to discussing the pathophysiology associated with diabetes-induced cardiovascular injury, available evidence pertaining to the cardiovascular protective potential of lanosteryl triterpenes from Protorhus longifolia will be discussed.

Scientific rationale for traditional use of plants to treat tuberculosis in the eastern region of the OR Tambo district, South Africa

Ethnopharmacological relevanceTuberculosis (TB) remains a major health problem for humans worldwide, and was responsible for 1.4 million human deaths in 2015 alone. Although there is treatment for TB, emerging multi-drug, extensively drug and totally drug resistant forms of this disease, as well as co-infection with human immunodefiency virus (HIV) continue to worsen the situation. South Africa is among countries with reported traditional use and published documentation of such knowledge concerning the use of plants against TB. Based on a previous study where plants used traditionally for treating TB in the eastern region of OR Tambo district, South Africa, were documented, the present study aimed to determine the antimycobacterial effect, cytotoxicity and genotoxicity of plants selected from that list. Material and methodsAcetone, 70% ethanol, cold and hot water extracts were tested for antimycobacterial activity against saprophytic Mycobacterium species including M. aurum, M. bovis BCG, M. gordonae, M. fortuitum, and M. smegmatis using a microdilution method. Extracts with MIC values less than 1 mg/ml against at least three Mycobacterium strains were evaluated for antimycobacterial activity against pathogenic Mycobacterium strains including M. tuberculosis H37RV, M. tuberculosis and M. bovis, cytotoxicity (against Vero monkey kidney and bovine dermis cells), and genotoxicity (against Salmonella typhimurium TA98 and TA100). ResultsThe MIC values of the extracts ranged from 0.02 to 2.50 mg/ml, LC50 values of twenty-nine extracts ranged from 0.001 to > 1 mg/ml and the highest selectivity index was 79.50, an extremely promising value. Phymaspermum acerosum roots and leaves (ethanol and water) extracts had the best MIC value (0.02 mg/ml) against at least one Mycobacterium strain. It was interesting to note the lack of cytotoxicity of these extracts with the highest selectivity index value of 39.75. Pterocelastrus echinatus bark acetone and Protorhus longifolia leaf hot water extracts were the most cytotoxic with LC50 = 0.001 and 0.008 mg/ml, respectively, whereas Pittosporum viridiflorum bark water extract was genotoxic. Among non-pathogenic strains, M. gordonae, M. aurum, M. smegmatis showed good correlation of activity with pathogenic M. tuberculosis H37Rv, M. tuberculosis and M. bovis, however, M. aurum was the best predictor with Mycobacterium tuberculosis H37Rv (correlation coefficient value = 0.73). ConclusionThe results indicate that Heteromorpha trifoliata and Phymaspermum acerosum should be investigated further for antimycobacterial efficacy against drug resistant strains of Mycobacterium.

A Lanosteryl Triterpene from Protorhus longifolia Improves Glucose Tolerance and Pancreatic Beta Cell Ultrastructure in Type 2 Diabetic Rats.

Type 2 diabetes remains one of the leading causes of death worldwide. Persistent hyperglycemia within a diabetic state is implicated in the generation of oxidative stress and aggravated inflammation that is responsible for accelerated modification of pancreatic beta cell structure. Here we investigated whether a lanosteryl triterpene, methyl-3β-hydroxylanosta-9,24-dien-21-oate (RA-3), isolated from Protorhus longifolia can improve glucose tolerance and pancreatic beta cell ultrastructure by reducing oxidative stress and inflammation in high fat diet and streptozotocin-induced type 2 diabetes in rats. In addition to impaired glucose tolerance, the untreated diabetic rats showed increased fasting plasma glucose and C-peptide levels. These untreated diabetic rats further demonstrated raised cholesterol, interleukin-6 (IL-6), and lipid peroxidation levels as well as a destroyed beta cell ultrastructure. Treatment with RA-3 was as effective as metformin in improving glucose tolerance and antioxidant effect in the diabetic rats. Interestingly, RA-3 displayed a slightly more enhanced effect than metformin in reducing elevated IL-6 levels and in improving beta cell ultrastructure. Although the involved molecular mechanisms remain to be established, RA-3 demonstrates a strong potential to improve pancreatic beta cell ultrastructure by attenuating impaired glucose tolerance, reducing oxidative stress and inflammation.

An ethnobotanical survey of plants used traditionally to treat tuberculosis in the eastern region of O.R. Tambo district, South Africa

Worldwide, tuberculosis (TB) is a major human killer claiming about 1.5 million lives per annum. Medicinal plants are believed to serve as a source for products that can serve as anti-TB agents. Despite the importance of plants for human health and subsistence in both developed and developing countries, loss of biodiversity-based cultural knowledge and traditions is a commonly reported phenomenon, therefore, documenting such knowledge before it disappears completely is a necessity. The study was carried out to document medicinal plants that are traditionally used for the treatment of TB in the eastern region of O.R. Tambo district, Eastern Cape Province of South Africa. Information about plants (names, parts and methods of preparation) that are used for treating TB was gathered from traditional medical practitioners (TMP) using questionnaires. Twenty-four plant species belonging to 19 families that are used for the treatment of TB were revealed by this study. The Apiaceae, Amaryllidaceae, Asparagaceae, Compositae, and Leguminosae were the most prominent, represented by two species each. Out of the 24 plants reported, Protorhus longifolia (Bernh.) Engl (Anacardiaceae), Phymaspermum acerosum Källersjö (Compositae) and Strychnos henningsii Gilg (Loganiaceae) were the most frequently mentioned species, and were reported for the first time for TB treatment. Most of the plants (91%) documented are administered orally; the root (54%) is the most common plant part used, while decoctions and infusions are the main preparatory methods. Indigenous knowledge of medicinal plants used in the treatment of TB exists in the eastern region of O.R. Tambo district, and TMP still play an important role in delivering primary health care services. The ethnobotanical information about the plant species mentioned in this study may serve as baseline data for future studies on their pharmacological effects and to identify those that have potential in the development of anti-TB drugs.

Antimycobacterial Activity and Low Cytotoxicity of Leaf Extracts of Some African Anacardiaceae Tree Species.

Treatment of tuberculosis (TB) is a challenge because of multidrug-resistant and extremely drug-resistant strains of Mycobacterium tuberculosis. Plant species contain antimicrobial compounds that may lead to new anti-TB drugs. Previous screening of some tree species from the Anacardiaceae family revealed the presence of antimicrobial activity, justifying further investigations. Leaf extracts of 15 Anacardiaceae tree species were screened for antimycobacterial activity using a twofold serial microdilution assay against the pathogenic Mycobacterium bovis and multidrug resistant M. tuberculosis and rapidly growing mycobacteria, Mycobacterium smegmatis, Mycobacterium fortuitum and Mycobacterium aurum. The vaccine strain, M. bovis and an avirulent strain, H37Ra M. tuberculosis, were also used. Cytotoxicity was assessed using a colorimetric assay against Vero kidney, human hepatoma and murine macrophage cells. Four out of 15 crude acetone extracts showed significant antimycobacterial activity with minimum inhibitory concentration varying from 50 to 100 µg/mL. Searsia undulata had the highest activity against most mycobacteria, followed by Protorhus longifolia. M. fortuitum was the strongest predictor of activity against multidrug-resistant TB (correlation coefficient = 0.65). Bioautography against M. aurum and M. fortuitum worked well as indicators of the Rf values of active compounds yielding strong zones of inhibition. The leaf extracts of S. undulata and P. longifolia had more than ten different antimycobacterial compounds and had low cytotoxicity with LC50 values above 100 µg/mL. Copyright © 2016 John Wiley & Sons, Ltd.

Cardioprotective potential of a lanosteryl triterpene from Protorhus longifolia

Context: The current rapid increase in the incidence of cardiovascular events indicates a need for the discovery of more effective cardioprotective agents.Objective: This study evaluated the cardioprotective potential of a lanosteryl triterpene from Protorhus longifolia (Benrh.) Engl. stem bark.Materials and methods: Spectroscopic data analysis was used to confirm the structure of methyl-3β-hydroxylanosta-9, 24-dien-21-oate (RA-3). The cardioprotective effect of RA-3 in isoproterenol-induced myocardial injury in hyperlipidemic rats was investigated. Rats were divided into the normal diet (ND) fed and high fat diet (HFD) fed groups. The HFD rats were further subdivided into three groups. The experimental group was orally administered with RA-3 (100 mg/kg) for 15 days. The rats were then injected with isoproterenol (85 mg/kg) to induce myocardial injury. At the end of the experiment, hearts and blood tissues were collected and used for histology and biochemical assays, respectively.Results: RA-3 exhibited a cardioprotective effect as it minimized myocardial injury in HFD rats. Few lesions of acute hyaline degeneration and reduced fat deposition were observed in the heart tissue of the triterpene pretreated rats. Lactate dehydrogenase (LDH) activity was decreased in the blood of the RA-3 pretreated rats (44.1 mU/mL) compared to the untreated group (64.8 mU/mL). Increased glutathione (GSH) content and catalase (CAT) activity along with lower levels of malondialdehyde (MDA) in the triterpene pretreated animals (120.8 nmol/μL) than in the non-treated HFD fed rats (143.6 nmol/μL) were also observed.Discussion and conclusion: The cardioprotective effect exhibited by RA-3 indicates its potential use in the management of cardiovascular diseases (CVD) and related health problems.

Functionalized Silver Nanoparticle Catalyzed [3+2] Cycloaddition Reaction: Greener Route to Substituted-1,2,3-triazolines

The [3+2] cycloaddition reaction between nitroolefins and alkyl/aryl azides was studied using functionalized silver nanoparticles (FnAgNPs) of average diameter 23 ± 1 nm as catalyst produced by the plant extract Protorhus longifolia. We found FnAgNPs to catalyze the reactions efficiently yielding a series of 1,5-disubstituted-1,2,3-triazolines under mild reaction conditions with no side products. The catalytic activity of FnAgNPs was compared with naked AgNPs and FnAgNPs found to be very effective. Except solvents, the whole experiments do not require any chemical/reagent which makes the process green.

In vivo antihyperglycemic activity of a lanosteryl triterpene from Protorhus longifolia.

Control of postprandial hyperglycemia is crucial in the management of diabetes mellitus. Despite the use of the current hypoglycemic drugs, incidence of diabetes and related diseases continue to increase. This study aimed at evaluating the in vivo antihyperglycemic activity of methyl-3β-hydroxylanosta-9,24-dien-21-oate (RA-3), a lanosteryl triterpene isolated, and characterized from Protorhus longifolia stem bark. Spectroscopic data analysis was used to establish and verify the structure of the triterpene. The antihyperglycemic activity of the triterpene was evaluated in an STZ-induced diabetes rat model. The experimental animals were orally administered with RA-3 (100 mg/kg body weight) daily for 14 days. An oral glucose tolerance test was also performed. The animals were euthanized and biochemical analysis of antioxidant status, some glycolytic enzymes and glycogen content were conducted on serum and liver samples, respectively. RA-3 exhibited hypoglycemic activity by reducing blood glucose levels by 37%. The triterpene also improved glucose tolerance in the diabetic rats. Relatively higher hepatic glycogen content, hexokinase and glucokinase activity with a decrease in glucose-6-phosphatase activity were observed in the triterpene-treated diabetic group when compared with the diabetic control group. The triterpene treatment further increased antioxidant status of the diabetic animals; increased activity of superoxide dismutase and catalase were observed along with a decrease in malondialdehyde content. The results indicate potential pharmaceutical effects of lanosteryl triterpene in the management of diabetes mellitus.

English

This work evaluated the anticoagulant and anti-inflammatory activity of a lanosteryl triterpene (3β-hydroxylanosta-9,24-dien-21-oic acid) isolated from Protorhus longifolia stem bark. Tail bleeding time assay was used to investigate the ex vivo anticoagulant activity. The effect of the triterpene on the thermally induced aggregation of malate dehydrogenase (MDH) and citrate synthase (CS) was studied. The anti-inflammatory activity of the triterpene was investigated using the cotton pellet-induced granuloma model in rats. Granuloma formation was measured following 7 days of oral administration of the experimental rats (two groups) with the triterpene at 50 and 250 mg/kg body weight (b.w). The compound (50 mg/kg) significantly (p < 0.05) increased bleeding time in rats by up to 7 min as compared to 2.5 min observed in the normal control group. It also improved the activity of Hsp70 on MDH and CS aggregation suppression. The reduction of the granuloma formation by up to 40.3% was observed. It is apparent that the triterpene has potential to inhibit the aggregation of proteins. Key words: Triterpene, anti-inflammatory activity, Protorhus longifolia, protein aggregation.

In vitro antihyperlipidemic potential of triterpenes from stem bark of Protorhus longifolia.

Two lanostane triterpenes, 3β-hydroxylanosta-9,24-dien-21-oic acid (1) and methyl-3β-hydroxylanosta-9,24-dien-21-oate (2), were isolated from the stem bark of Protorhus longifolia. Their structures were deduced on the basis of spectroscopic analysis (NMR, HRMS, IR). This study investigated the in vitro anti-adipogenic activity of the two triterpenes. Their inhibitory activity was evaluated on selected lipid digestive enzymes (pancreatic lipase and cholesterol esterase). The inhibitory activity of the compounds on hormone-sensitive lipase and their ability to bind bile acids were also evaluated. The effect of the compounds on glucose uptake in C2C12 muscle cells and 3T3-L1 adipocytes, and on triglyceride accumulation in 3T3-L1 adipocytes was investigated. The triterpenes effectively inhibited the activities of the enzymes with IC50 values ranging from 0.04 to 0.31 mg/mL. The compounds showed a high affinity for secondary bile acids. Both compounds stimulated glucose uptake in C2C12 muscle cells and 3T3-L1 adipocytes. Compound 1 significantly reduced triglyceride accumulation in mature differentiated 3T3-L1 adipocytes. It is apparent that these lanostane triterpenes enhance glucose uptake and suppress adipogenesis, which together with their inhibitory effects on lipid digestive enzymes suggests that they have antihyperlipidemic potential.

In vivo anti-hyperlipidemic activity of the triterpene from the stem bark of Protorhus longifolia (Benrh) Engl.

BackgroundHyperlipidemia, a metabolic disorder of lipids, is a well known risk factor of cardiovascular events and metabolic syndrome. In this study, the in vivo lipid-lowering activity of the triterpene (Methyl-3β-hydroxylanosta-9,24-dien-21-oate), isolated from the stem bark of Protorhus longifolia, in high fat diet (HFD)-induced hyperlipidemic rats was investigated.MethodsStructure of the isolated compound was established and confirmed based on spectral (NMR, HRMS, IR) data analysis. Rats were divided into two groups; normal group (fed the normal commercial rats’ chow) and the HFD group. After 21 days of experimental period on their respective diets, the HFD rats were sub-divided into 4 groups of six rats per group. Two of the HFD groups were orally treated with the triterpene (100 and 200 mg/kg body weight) for 15 days. At the end of the experimental periods, the rats were sacrificed and blood samples were collected for biochemical assays.ResultsThe results show that there were significant increases in total serum cholesterol (TC, 15.72 mmol/L) and low-density lipoprotein cholesterol (LDL-c, 7.41 mmol/L) with a reduction in high-density lipoprotein cholesterol (HDL-c, 14.75 mmol/L) in HFD-induced hyperlipidemic rats after 21 days. Oral administration of the triterpene (100 mg/kg.bw and 200 mg/kg.bw) for a period of 15 days resulted in significant lowering of the levels of TC (7.51 mmol/L) and LDL-c (4.46 mmol/L) with an increase in HDL-c (47.3 mmol/L) in HFD-induced hyperlipidemic rats. Significant decrease in atherogenic index and coronary risk index by the triterpene was observed in HFD-induced hyperlipidemic rats.ConclusionsThe triterpene could effectively reduce or control the amount of serum cholesterol and LDL. It is apparent that the compound could contribute to new formulation with significant hypolipidemic effects.Electronic supplementary materialThe online version of this article (doi:10.1186/1476-511X-13-131) contains supplementary material, which is available to authorized users.

English

Antibiotic resistance of pathogenic strains has hugely contributed to the wide spread of new and re-emerging infectious diseases. There is thus the need for the discovery of new (non-penicillin based) antibiotics. The triterpenes [3β-hydroxylanosta-9,24-dien-21-oic acid (1) and methyl-3β-hydroxylanosta-9,24-dienoate (2)] isolated from stem bark of Protorhus longifolia (Benrh.) Engl. were evaluated for their antibacterial activity against a panel of selected general and antibiotic resistant Gram positive and Gram negative bacteria. The antibacterial activity of the compounds was determined using disc diffusion method. The compounds exhibited antibacterial activity against most of the tested bacteria with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranging from 0.16 to 5.00 mg/ml and 0.63 to 5.00 mg/ml, respectively. The triterpenes did not exhibit any bacterial DNA damaging effects, but apparently affected the microbial cell membrane integrity. The triterpenes could be a potentially effective antimicrobial agent to combat infectious diseases. Key words: Triterpenes, antibacterial activity, antibiotic resistance, DNA damage.

In vitro antihyperlipidemic activity of triterpenes from stem Bark of Protorhus longifolia (Benrh) Engl.

Obesity is a common disorder of carbohydrate and fat metabolism. In an effort to discover new more effective drugs against obesity and its co-morbidities, we investigated the in vitro antihyperlipidemic activity of two triterpenes (3β-hydroxylanosta-9,24-dien-21-oic acid and methyl-3β-hydroxylanosta-9,24-dienoate isolated from stem bark of Protorhus longifolia and characterized through NMR, LC-MS, IR. The inhibitory activity of the triterpenes was evaluated on selected lipid (pancreatic lipase and cholesterol esterase) and carbohydrate (disaccharidases, α- glucosidase) digestive enzymes. The inhibitory activity of the compounds on hormone-sensitive lipase and the ability to bind bile acids were also evaluated. Furthermore, the effect of the compounds on cellular (muscle cells, C2C12 and fat cells, 3T3-L1) glucose uptake was investigated. The triterpenes effectively inhibited the activities of pancreatic lipase, cholesterol esterase, and hormone-sensitive lipase with IC50 values ranging from 26.6 to 430 µg/ml, and showed to varying degree inhibition of maltase and other disaccharidases. The compounds showed moderate bile acid binding ability and at 50 µg/ml, both compounds also mimicked insulin character by effectively stimulating glucose uptake in both the C2C12 and 3T3-L1 cells. It is apparent that the compounds possess hypolipidemic properties.