Insecticidal activities and chemical composition of the essential oil from Tarchonanthus camphoratus (L.), leaves against Sitophilus zeamais Motschulsky, and Sitophilus oryzae (L.)

The essential oil of Tarchonanthus camphoratus dry leaves growing in Kwa-Zulu Natal, South Africa was obtained by hydrodistillation and evaluated for its repellent effect, contact and fumigation toxicity against both Sitophilus zeamais and Sarocladium oryzae. Chemical composition of the essential oil was analysed by gas chromatography mass spectrometry (GC/MS). The study revealed that the essential oil of T. camphoratus had no contact and fumigation toxicity against stored insect pests, S. zeamais and S. oryzae. The oil, however, showed good repellent activity of over 50% after 24 h for all the concentrations used on both S. zeamais and S. oryzae. A total of 27 compounds accounting for 73% of the total oil composition were identified of which sesquiterpene hydrocarbons, (59.18%), were the most dominant. These results suggest that the essential oil of T. camphoratus could be considered a potential control agent of stored grain pests as a repellent

Anti-oxidant, anti-inflammatory and antiacetylcholinesterase activity of betulinic acid and 3β- acetoxybetulinic acid from Melaleuca bracteata ‘Revolution Gold’

Purpose: To evaluate the anti-oxidant, anti-inflammatory and anti-acetylcholine esterase activities of betulinic acid (BA) and 3β- acetoxybetulinic acid (BAA) from Melaleuca bracteata. ‘Revolution Gold’.Methods: Betulinic acid was isolated from the ethyl acetate extract of M. braceteata while BAA was synthesized by acetylation of BA. Structural elucidation of the compounds was achieved by spectroscopic methods. Antioxidant potential was determined using superoxide dismustase (SOD) and catalase assay kits while iron chelation activity assessed with ferrozin. Anti-inflammatory activity was determined using cotton pellet-induced granuloma rat model. Cyclooxygenase (COX) activity evaluated by COX kits; acetylcholine kit was used for anti-acetylcholinesterase (ACHE) study.Results: The compounds significantly (p < 0.05) dose-dependently inhibited ACHE and inflammatory activity. They also significantly decreased the inhibition of SOD, catalase activity but increased iron chelation activities in a dose-dependent manner. However, BAA showed higher activity than BA for all the parameters. BAA also had a greater inhibitory effect on COX-2 than on COX-1. BAA (IC50, 0.88 mg/mL) showed better iron chelation than citric acid (0.96 ± 0.04) and EDTA (1.04 ± 0.03), the positive control.Conclusion: BA and BAA possess anti-ACHE, anti-inflammatory, antioxidant and anti-COX activities. Structural modification of BAA influences its biological activities. Therefore, BAA can potentially serve as a scaffold in synthesizing potent neurodegeneration drugs.Keywords: Betulinic acid, 3β-Acetoxybetulinic acid, Antioxidant, Anti-inflammatory, Antiacetylcholinesterase, Melaleuca bracteata. ‘Revolution Gold

Antithrombotic, anticoagulant and antiplatelet activity of betulinic acid and 3β-acetoxybetulinic acid from Melaleuca bracteata ‘Revolution Gold’ (Myrtaceae) Muell leaf

Purpose: To investigate the antithrombotic, anticoagulant and antiplatelet activity of betulinic acid (BA) and 3β-acetoxybetulinic acid (BAA) from Melaleuca bracteata ‘Revolution Gold’.Methods: Betulinic acid was isolated from the ethyl acetate extract of M. bracteata leaves by column chromatography, from which BAA was subsequently synthesized by acetylation. Structural elucidation of the compounds was conducted using mass spectrometry (MS), infra-red (IR) spectroscopy and nuclear magnetic resonance (NMR). The antithrombotic potential of the compounds was assessed using chromogenic substrate. Anticoagulation studies were carried using bleeding tail time assay in a rat model. Plasma-rich platelets from rats were employed for platelet aggregation studies using light microscope.Results: The compounds significantly (p < 0.05) showed antithrombotic activities in a dose-dependent manner. BAA showed significantly (p < 0.05) higher half-maximal concentration (IC50) value of 1.10 ± 0.03 mg/mL than BA (2.36 ± 0.09 mg/mL) and aspirin (2.65 ± 0.01 mg/mL) which served as positive control. The compounds exhibited anticoagulation activity with poor bleeding time, compared to aspirin. Likewise, the compounds attenuated platelets aggregation induced by thrombin.Conclusion: BAA displays better antithrombotic, antiplatelet, and anticoagulant activities than BA. Therefore, it may be a promising remedy for the management of cardiovascular events.Keywords: Betulinic acid, Thrombin, Anticoagulation, Antiplatelet, Aspirin, Platelet

In vitro and in vivo antioxidant potentials of the methanolic crude extract from Inula glomerata Oliv. & Hiern (Asteraceae) and Salacia kraussii (Harv.) Harv (Celastraceae)

Reactive oxygen species are implicated in multiple pathological conditions including erectile dysfunction. This study evaluated the in vitro and in vivo antioxidant potential of the methanolic extracts of Inula glomerata and Salacia kraussii. The plant materials were pulverized and extracted with methanol. The phytochemical analysis, ability of the crude extracts to scavenge free radicals (ABTS, DPPH, NO.) in vitro as well as the total phenolic and flavonoid contents was investigated. In vivo, antioxidant potentials of the crude extracts (50/250 mg/kg body weight) were determined in an erectile dysfunction rat model. The phytochemical analysis revealed that both plants contain flavonoids, tannins, terpenoids, and alkaloids. The crude extracts at varying degree of efficiency, scavenged ABTS and DPPH radicals. The crude extracts at low concentrations (50 mg/kg b.w) significantly (p<0.05) diminished the level of malondialdehyde, augmented catalase activities and elevated glutathione levels. However, SOD activities were significantly boosted in a dose-dependent manner by the crude extracts. Therefore, I. glomerata and S. kraussii possess antioxidant properties, hence, can serve as a therapeutic modality in the treatment of oxidative stress-induced erectile dysfunction.https://blacpma.ms-editions.cl/index.php/blacpmapm2021BiochemistryGeneticsMicrobiology and Plant Patholog

The triterpene, methyl-3β-hydroxylanosta-9,24-dien-21-oate (RA3), attenuates high glucose-induced oxidative damage and apoptosis by improving energy metabolism

BACKGROUND: Hyperglycemia-induced cardiovascular dysfunction has been linked to oxidative stress and accelerated apoptosis in the diabetic myocardium. While there is currently no treatment for diabetic cardiomyopathy (DCM), studies suggest that the combinational use of anti-hyperglycemic agents and triterpenes could be effective in alleviating DCM. HYPOTHESIS: To investigate the therapeutic effect of methyl-3β-hydroxylanosta-9,24-dien-21-oate (RA3), in the absence or presence of the anti-diabetic drug, metformin (MET), against hyperglycemia-induced cardiac injury using an in vitro H9c2 cell model. METHODS: To mimic a hyperglycemic state, H9c2 cells were exposed to high glucose (HG, 33 mM) for 24 h. Thereafter, the cells were treated with RA3 (1 μM), MET (1 μM) and the combination of MET (1 μM) plus RA3 (1 μM) for 24 h, to assess the treatments therapeutic effect. RESULTS: Biochemical analysis revealed that RA3, with or without MET, improves glucose uptake via insulindependent (IRS-1/PI3K/Akt signaling) and independent (AMPK) pathways whilst ameliorating the activity of antioxidant enzymes in the H9c2 cells. Mechanistically, RA3 was able to alleviate HG-stimulated oxidative stress through the inhibition of reactive oxygen species (ROS) and lipid peroxidation as well as the reduced expression of the PKC/NF-кB cascade through decreased intracellular lipid content. Subsequently, RA3 was able to mitigate HG-induced apoptosis by decreasing the activity of caspase 3/7 and DNA fragmentation in the cardiomyoblasts. CONCLUSION: RA3, in the absence or presence of MET, demonstrated potent therapeutic properties against hyperglycemia-mediated cardiac damage and could be a suitable candidate in the prevention of DCM.South African National Treasury and National Research Foundation.https://www.elsevier.com/locate/phymedpm2022BiochemistryGeneticsMicrobiology and Plant Patholog

<em>Melaleuca bracteata</em> var. Revolution Gold (Myrtaceae) Essential Oil: Chemical Composition, Antibacterial, Membrane Damage, Antiplatelet Aggregation and Antiacetylcholinesterase Activities

Melaleuca bracteata var. Revolution Gold (a cultivar of Melaleuca bracteata) is an ornamental plant, which has been used in traditional medicine for the treatment of several diseases. Till moment, information is scanty on the biological activities of the essential oil from the plant. The water-distilled essential oil was analyzed by gas chromatography and gas chromatography-mass spectrometry. Antibacterial activity of the oil was evaluated by paper disc diffusion and micro-dilution methods. Cell membrane damage was assay using cytosolic lactate dehydrogenase released method. Platelet aggregation inhibitory activity was separately evaluated on Adenosine diphosphate, collagen, epinephrine and thrombin induced aggregation. Thirteen components representing 95.3% of the total oil were identified from the essential oil. Phenylpropanoids (82.9%) constitute the predominant class of compounds in the oil. On the whole, the oil displayed strong antibacterial action towards Staphylococcus aureus, moderate activity on Bacillus cereus and some strains of Escherichia coli. The lactate dehydrogenase released (0.78–47%) depicted the oil to exhibit low levels of membrane damage. The percentage platelet aggregation inhibition for the four platelet agonists was concentration dependent with thrombin > collagen > ADP > epi-nephrine. The acetylcholinesterase inhibitory activity (9.16%) indicated that the essential oil was not effective against the enzyme

Anti-Plasmodial Activity of Some Zulu Medicinal Plants and of Some Triterpenes Isolated from Them

Mimusops caffra E. Mey. ex A.DC and Mimusops obtusifolia Lam (both members of the Sapotaceae family), and Hypoxis colchicifolia Bak (family Hypoxidaceae) are used by traditional healers in Zululand to manage malaria. Anti-plasmodial investigation of the crude extracts and some triterpenes isolated from the plants showed activity against a chloroquine sensitive (CQS) strain of Plasmodium falciparum (D10). Among the crude extracts the leaves of M. caffra exhibited the highest activity, with an IC50 of 2.14 μg/mL. The pentacyclic tritepenoid ursolic acid (1), isolated from the leaves of M. caffra was the most active compound (IC50 6.8 μg/mL) as compared to taraxerol (2) and sawamilletin (3) isolated from the stem bark of M. obtusifolia (IC50 > 100). Chemical modification of the ursolic acid (1) to 3β-acetylursolic acid (4) greatly enhanced its anti-plasmodial activity. Compound 4 reduced parasitaemia against Plasmodium berghei by 94.01% in in vivo studies in mice. The cytotoxicity of 3β-acetylursolic acid (IC50) to two human cell lines (HEK293 and HepG2) was 366.00 μg/mL and 566.09 μg/mL, respectively. The results validate the use of these plants in folk medicine

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

Isolation, characterization, and biological evaluation of a potent anti-malarial drimane sesquiterpene from Warburgia salutaris stem bark

Abstract Background Malaria continues to be a global burden as the efficacy of most commercial anti-malarial drugs has been compromised by the evolution of parasite resistance. With the urgent need created for the development of alternative and more efficient anti-malarial drugs, this study focused on the evaluation of anti-malarial agents of the Warburgia salutaris stem bark. Methods The stem bark was extracted with dichloromethane followed by silica gel column chromatography that led to the isolation of iso-mukaadial acetate, a drimanoid sesquiterpene. This compound was characterized by spectroscopic analysis (1H NMR, 13C NMR, IR and MS), and its structure was confirmed by X-ray crystallography. In vitro anti-plasmodial activity was investigated using a chloroquine sensitive NF54 Plasmodium falciparum strain. Cytotoxicity was measured using the MTT assay on HEK239 and HEPG2 cell lines. Chloroquine-sensitive Plasmodium berghei was used to infect Sprague–Dawley rats for in vivo studies. The W. salutaris crude extract and iso-mukaadial acetate were administered orally at 0.5; 1.5, 2.5 and 5 mg/kg, chloroquine was used as the reference drug. Determination of percentage parasitaemia, haematological parameters, and rat body weights was done throughout the experimental study period. Results The crude extract and iso-mukaadial acetate showed very good activity on the inhibition of parasite growth (IC50 0.01 ± 0.30 µg/ml) and (IC50 0.44 ± 0.10 µg/ml), respectively, with iso-mukaadial acetate having cytotoxicity activity of 36.7 ± 0.8 and 119.2 ± 8.8 (µg/ml) on HEK293 and HEPG2 cells, respectively. The crude extract and iso-mukaadial acetate reduced percentage parasitaemia in a dose-dependent manner in comparison to the control. There were no significant differences in the haematological parameters in all the experimental groups in comparison to control group. This study proves that W. salutaris contains components (including iso-mukaadial acetate) that exhibit anti-malarial activity. This study scientifically validates the use of this plant in folk medicine. Conclusions This study proves that Warburgia salutaris contains components (including iso-mukaadial acetate) that exhibit anti-malarial activity and scientifically validates the use of this plant in folk medicine