Three new dihydrochalcones from the leaves of Artocarpus sericicarpus Jarrett and their activity against Plasmodium falciparum.

Three new dihydrochalcones: artoserichalcone A-C (1-3), were isolated from the leaves of Artocarpus sericicarpus. The structures of compounds were determined based on NMR spectrum (1H, 13C, and 2D) and HRESIMS spectroscopic analysis. Compounds (1) and (3) showed active antimalarial activity with IC50 values of 16.90 and 13.56 µM, respectively. Meanwhile, compound (2) with an IC50 value of 63.01 µM was categorised as a moderate antimalarial substance. The cytotoxicity against Huh7, HepG2, BHK-21, and Vero cells showed that compounds (1-3) with CC50 values > 20 µg/mL could be considered non-cytotoxic. Compounds (1-3) exhibited antimalarial activity against Plasmodium falciparum and non-toxic as an antimalarial agent.

Promising alkaloids and flavonoids compounds as anti-hepatitis c virus agents: a review.

Background: Virus infections are presently seen as a major public health problem. Hepatitis C Virus (HCV) is recognized as a "silent killer" because the acute infection has no symptoms, and it develops as a chronic infection that causes hepatocellular carcinoma and liver damage. The World Health Organization (WHO) predicts that between 130-170 million people are estimated to have chronic Hepatitis C. Plants have various phytochemical compounds such as alkaloids and flavonoids that have prominent antiviral effects especially anti-HCV. The current HCV treatment still has limitations related to side effects and can lead to viral resistance. Therefore, it is necessary for the discovery and development of novel anti-HCV drugs for alternative and complementary medicine. Objective: This review intends to evaluate the alkaloids and flavonoids that have the potential to be used against HCV by looking at their classification and their mechanism of action. Methods: Twenty-one articles from 2010 to 2022 obtained from PUBMED database using keywords such as isolated compounds, alkaloids, flavonoids, hepatitis C virus. Results: 21 alkaloids and 37 flavonoids reported active against HCV. Alkaloids include quinoline, quinolizidine and isoquinoline. In addition, flavanone, flavonol, flavone, flavan-3-ol, flavonolignan, anthocyanidin and proanthocyanidin comprise flavonoids. The berberine alkaloids and eriodictyol 7-O-(6″-caffeoyl)-ß-Dglucopyranoside flavonoids had the lowest IC50 with values of 0.49 mM and 0.041 nM. Conclusions: Alkaloids and flavonoids compound had good activity against HCV with various mechanisms. Our results provide information of alkaloids and flavonoids to the researcher for the development of alternative and complementary medicine of hepatitis C.

Effect of geranylated dihydrochalcone from Artocarpus altilis leaves extract on Plasmodium falciparum ultrastructural changes and mitochondrial malate: Quinone oxidoreductase.

Nearly half of the world's population is at risk of being infected by Plasmodium falciparum, the pathogen of malaria. Increasing resistance to common antimalarial drugs has encouraged investigations to find compounds with different scaffolds. Extracts of Artocarpus altilis leaves have previously been reported to exhibit in vitro antimalarial activity against P. falciparum and in vivo activity against P. berghei. Despite these initial promising results, the active compound from A. altilis is yet to be identified. Here, we have identified 2-geranyl-2', 4', 3, 4-tetrahydroxy-dihydrochalcone (1) from A. altilis leaves as the active constituent of its antimalarial activity. Since natural chalcones have been reported to inhibit food vacuole and mitochondrial electron transport chain (ETC), the morphological changes in food vacuole and biochemical inhibition of ETC enzymes of (1) were investigated. In the presence of (1), intraerythrocytic asexual development was impaired, and according to the TEM analysis, this clearly affected the ultrastructure of food vacuoles. Amongst the ETC enzymes, (1) inhibited the mitochondrial malate: quinone oxidoreductase (PfMQO), and no inhibition could be observed on dihydroorotate dehydrogenase (DHODH) as well as bc1 complex activities. Our study suggests that (1) has a dual mechanism of action affecting the food vacuole and inhibition of PfMQO-related pathways in mitochondria.

Acacia mangium: A promising plant for isolating anti-hepatitis C virus agents.

Background: Medicinal plants are potential resources for isolating drug candidates. Various plants have been reported to possess pharmacological effects including anti-hepatitis C activities. The current study examined the anti-hepatitis C virus (HCV) activities of Acacia mangium extracts in solvents with various polarities and further evaluated the mechanism of action of the extracts using Western blotting and combination treatment models. Methods: The leaves of A. mangium were extracted in two phases, first in ethanol and then in solvents with different polarities (n-hexane, dichloromethane, and methanol). HCV-infected Huh7it-1 cells were treated with the extracts at concentrations of 0.01, 0.1, 1, 10, 50, and 100 µg/mL. Results: The results revealed the strong anti-HCV activities of the extracts. The 50% inhibition concentrations (IC 50s) of the ethanol, n-hexane, dichloromethane and methanol extracts were of 4.6 ± 0.3, 2.9 ± 0.2, 0.2 ± 0.3, and 2.8 ± 0.2 µg/mL, respectively, and no cytotoxic effect was detected. These extracts displayed stronger effects than the positive control ribavirin. The mode of action of the ethanol extract was evaluated at 30 µg/mL, revealing that the inhibitory effect was stronger on the post-entry step than on the entry step. Western blotting revealed that the extracts decreased NS3 protein expression, indicating that virus replication was suppressed. Further evaluation illustrated that combined treatment with the ethanol extract enhanced the anti-viral activity of simeprevir. Conclusions: These results indicated that A. mangium leaves could represent sources of anti-HCV agents.

An in vitro study of an Artocarpus heterophyllus substance as a hepatitis C antiviral and its combination with current anti-HCV drugs.

BACKGROUND: Current therapy of chronic hepatitis C virus (HCV) with direct-acting antivirals (DAAs) has dramatically improved the sustained virologic response (SVR) of affected patients; however, treatment with DAAs remains expensive, and drug-resistant HCV variants remain a threat. As a result, there is still a need to continue to develop affordable and effective drugs for the treatment of HCV. Previously, we have demonstrated that a crude extract from Artocarpus heterophyllus leaves is a potential anti-HCV candidate. In this study, we have further purified this crude extract, examined which sub-fraction possesses the highest antiviral activity, and then explored its efficacy at different HCV life cycle stages. We also assessed synergistic antiviral effects between the A. heterophyllus extract and commercially available anti-HCV drugs. METHODS: We used vacuum liquid chromatography (VLC) and high-performance liquid chromatography (HPLC) to fractionate a dichloromethane extract of A. heterophyllus leaves. We then examined the anti-HCV activity of the fractions using HCV genotype 2a, JFH1a; the antiviral mode of action was determined by exploring adding the treatments at different times. We examined the antiviral effects on the viral entry stage through a virucidal activity test, viral adsorption examination, and pretreatment of cells with the drug. The effects on the post-viral entry stage were determined by the levels of HCV protein expression and HCV RNA expression in infected cells. RESULTS: Through activity guided purification, we identified the sub-fraction FR3T3 as possessing the most robust anti-HCV activity with an IC50 value of 4.7 ± 1.0 µg/mL. Mode-of-action analysis revealed that FR3T3 inhibited post-viral entry stages such as HCV NS3 protein expression and HCV RNA replication with marginal effects on the viral entry stage. Thin-layer Chromatography (TLC) indicated that FR3T3 contained terpenoids and chlorophyll-related compounds. We also found a synergistic antiviral activity when the DCM extract of A. heterohyllus was used in combination therapy with commercial anti-HCV drugs; Ribavirin, Simeprevir, Cyclosporin A. CONCLUSIONS: The extract of A. heterophyllus and its sub-fraction, FR3T3, presented here have anti-HCV activities and could be candidate drugs for add-on-therapy for treatment of chronic HCV infections.

In vitro antimalarial activity of Garcinia parvifolia Miq. Stem extracts and fractions on Plasmodium falciparum lactate dehydrogenase (LDH) assay.

OBJECTIVES: The rapid spread of antimalarial drug resistance is becoming a problem in the treatment of malaria. The fact was indicated the importance of finding new antimalarial drugs. The genus Garcinia is well known to be a rich source of bioactive prenylated xanthones and triterpenes reported for their antimalarial activity. Garcinia parvifolia is one of the Garcinia genera that can be explored for the search of new antimalarial drugs. This study was aimed to determine the antimalarial activities of G. parvifolia extracts and fractions. METHODS: Garcinia parvifolia Miq. stem was collected from Balikpapan Botanical Garden in East Kalimantan, Indonesia, was extracted gradually with n-hexane, dichloromethane, and methanol by ultrasonic assisted method. The most active extract was further separated using the open column chromatography method. All extracts and fractions were tested against Plasmodium falciparum 3D7 using lactate dehydrogenase (LDH) assay and followed by IC50 determination. RESULTS: The results showed that all extracts inhibit P. falciparum growth by LDH assay. The highest inhibition was showed by dichloromethane stem extract (BP12-S-D) with the IC50 value of 6.61 ± 0.09 µg/mL. Further fractionation of BP12-S-D has obtained 10 fractions. All of them were identified by TLC, and a brownish-yellow spot (fraction-1) appears after spraying with 10% H2SO4. Fraction-1 (F1) performed the highest parasite growth inhibition with the IC50 value of 6.00 ± 0.03 µg/mL compared with other fractions. This fraction was classified as having a promising activity of antimalarial. The fraction-1 was identified using HPLC, and two major peaks were observed (A and B). The UV-Vis spectra showed the absorption at wavelengths 250 and 278 (A), 243, 281, and 317 nm (B). Based on the profile of TLC, HPLC, and UV-Vis spectra of F1, it was expected that the active compounds are flavonoid (A) and xanthone (B). CONCLUSIONS: The fraction-1 of dichloromethane extract of G. parvifolia Miq. stem has the highest antimalarial activity. It might be a potential candidate for the new antimalarial drug.

Artocarpus sericicarpus stem bark contains antimalarial substances against Plasmodium falciparum.

OBJECTIVES: The finding of alternative medicine for malarial treatment still has become a substantial demand. The plant is one of the potential sources of drugs, among other natural sources. Artocarpus species showed great potential as the antimalarial source. This study aims to obtain active antimalarial fractions from Artocarpus sericicarpus stem bark. METHODS: Stem bark of A. sericicarpus was extracted by ultrasonic-assisted extraction method using n-hexane, dichloromethane, and methanol as solvents. Fractionation of dichloromethane extract was conducted by open column chromatography using octadecyl silica as a stationary phase and gradient acetonitrile-water as a mobile phase. The antimalarial activity was determined by lactate dehydrogenase (LDH) assay against Plasmodium falciparum 3D7 strain. RESULTS: A. sericicarpus n-hexane, dichloromethane, and methanol extracts were showed antimalarial activity with an IC50 value of >4, 2.11, and >4 µg/mL, respectively. Fractionation of dichloromethane extract was obtained 13 fractions. Seven of the 13 fractions tested showed antimalarial activity. Fraction-6 performed the highest inhibition with an IC50 value of 1.53 ± 0.04 µg/mL. Phytochemistry screening revealed that Fraction-6 contains flavonoid, polyphenol, and terpenoid compounds that can take a role in its antimalarial activity. CONCLUSIONS: A. sericicarpus contains antimalarial substances mainly in Fraction-6, which strongly inhibited the growth of P. falciparum. The flavonoid, polyphenol, and terpenoid compounds were identified in Fraction-6, which need to be further isolated to obtain and elucidate the active antimalarial compounds.

Cratoxylum sumatranum stem bark exhibited antimalarial activity by Lactate Dehydrogenase (LDH) assay.

OBJECTIVES: The antimalarial drug resistance is an obstacle in the effort to overcome malaria. The new alternative antimalarial drug became in great attention of urgent need. Current antimalarial drugs were derived from plants. Therefore, the plant is considering a potential source of new drugs. Cratoxylum sumatranum belongs to the Hypericaceae family contain xanthones and phenolic compounds, which was reported for their antimalarial activities. This study aims to determine the antimalarial activities of C. sumatranum extracts and fractions. METHODS: Cratoxylum  sumatranum stem bark (BP14-SB) collected from Balikpapan Botanical Garden in East Kalimantan, Indonesia, was extracted gradually with n-hexane, dichloromethane, and methanol by ultrasonic-assisted extraction method. All extracts were tested against Plasmodium falciparum 3D7 by lactate dehydrogenase (LDH) assay and followed by IC50 determination. The most active extract was further separated and tested for their antimalarial activities. RESULTS: The results showed that dichloromethane stem bark extract (BP14-SB-D) had the strongest inhibition of parasite growth with the IC50 value of 0.44 ± 0.05 µg/mL and moderately toxic with the CC50 value of 29.09 ± 0.05 µg/mL. Further fractionation of BP14-SB-D by open column chromatography using silica gel and gradient hexane-ethyl acetate obtained 12 fractions. LDH assay for these 12 fractions of BP14-SB-D showed that Fraction-6 (IC50 value of 0.19 ± 0.03 µg/mL) was performed the strongest inhibition of parasite growth, compared to other fractions. TLC identification showed that BP14-SB-D contains xanthone. CONCLUSIONS: The dichloromethane extract of C. sumatranum stem bark (BP14-SB-D) and Fraction-6 from this extract exhibited antimalarial activity and the potential to be developed an antimalarial substance.

Analgesic and Antipyretic Activities of Ethyl Acetate Fraction Tablet of Andrographis paniculata in Animal Models.

OBJECTIVES: To determine the analgesic and antipyretic activities of a tablet derived from Andrographis paniculata ethyl acetate fraction (AS201-01) in animal models. METHODS: The tablet derived from AS201-01 contains an equivalent of 35 mg andrographolide per tablet. Analgesic activity was determined using an acetic acid-induced writhing test on adult male mice. A writhe was recorded by a stopwatch and was defined as the stretching of the abdomen and/or stretching of at least one hind limb. For the determination of antipyretic activity, pyrexia was induced by subcutaneous injection of 15% w/v Brewer's yeast into adult male rats. Rectal temperature was monitored at 1, 2, 3, and 4 hours after treatment. RESULTS: The results showed that the AS201-01 tablet had analgesic and antipyretic activity. In the acetic acid-induced writhing model, AS201-01 tablet exhibited significant analgesic effect with a 66.73% reduction in writhing response at a dose of 50 mg andrographolide/kg body weight compared to the negative control group. The tablet also showed a significant antipyretic effect. The maximum antipyretic effect was observed after the third hour of administration of the AS201-01 tablet at a dose of 100 mg andrographolide/kg body weight. CONCLUSION: Tablet of Andrographis paniculata ethyl acetate fraction (AS201-01) exhibited analgesic and antipyretic activities.

A tablet derived from Andrographis paniculata complements dihydroartemisinin-piperaquine treatment of malaria in pregnant mice.

OBJECTIVES: The use of standard antimalarial drugs, such as dihydroartemisinin-piperaquine (DHP) for the treatment of malaria during pregnancy is limited due to the risk of teratogenicity. The alternative is therefore required although few exist. Here we show a phytopharmaceutical drug derived from Andrographis paniculata (AS201-01), which is effective as herbal antimalarial both in vitro and in vivo and may be a suitable alternative when used in complementary treatment with DHP. METHODS: Plasmodium berghei infected pregnant BALB/c mice were divided into four groups: G1 (negative control), G2 (AS201-01), G3 (DHP), and G4 (combination of DHP and AS201-01). Pheripheral blood was collected during therapy for counting parasitemia. Placental samples were analyzed for the expression of IFN-γ, TNF- α, IL-10, placental parasite counts and foetal morphology. RESULTS: Groups G4 and G3 both showed a 100% inhibition of peripheral parasitemia. However, the treatment in G4 was found to be less effective than that in G2 and G3 in preventing placental parasitemia. The G4 treatment was able to reduce the expression of IFN-γ and IL-10, whereas TNF-α was not significantly different from the control group. Foetal morphologic abnormalities were observed in all groups except G2; G4 showed lower percentage of abnormalities compared to G3 and G1. CONCLUSIONS: A combination of A. paniculata tablet (AS201-01) with DHP has the potential to reduce the toxicity of DHP in malaria treatment.

Alkaloid and benzopyran compounds of Melicope latifolia fruit exhibit anti-hepatitis C virus activities.

BACKGROUND: New agents for developing alternative or complementary medicine to treat the hepatitis C virus (HCV) are still needed due to high rates of HCV infection globally and the current limitations of available treatments. Treatment of HCV with a combination of direct acting antivirals have been shown to be approximately 90% effective but will be limited in the future due to the emergence of drug resistance and high cost. The leaves of Melicope latifolia have previously been reported to have anti-HCV activity and are a potential source of bioactive compounds for future novel drug development. This study aimed to evaluate the efficacy of the extract of M. latifolia fruit to treat HCV and to isolate its active compounds. METHOD: M. latifolia fruit was extracted using methanol and purified using vacuum liquid chromatography (VLC) and Radial Chromatography. The anti-HCV activity was analyzed using cell culture lines Huh7it-1 and JFH1 (genotype 2a). Time-of-addition and immunoblotting studies were performed to identify the mode of action of the isolated active compounds. The structures of the active compounds were determined using nuclear magnetic resonance (NMR) spectra, UV, IR, and Mass Spectra. RESULTS: Six known compounds were isolated from M. latifolia fruit: O-methyloktadrenolon, alloevodionol, isopimpinellin, alloxanthoxyletin, methylevodionol, and N-methylflindersine. N-methylflidersine was the most active compound with IC50 value of 3.8 µg/ml while methylevodionol, isopimpinellin, and alloevodionol were less active. O-methyloktadrenolon and alloxanthoxyletin were moderately active with IC50 values of 10.9 and 21.72 µg/ml, respectively. N-methylflidersine decreased level of HCV NS3 protein expression in the cells. CONCLUSION: The alkaloid compound, N-methylflindersine which was isolated from M. latifolia possesses anti-HCV activity through post-entry inhibition and suppressed NS3 protein expression.

Bioanalytical method development and validation for quantification of morachalcone A in rabbit plasma using high performance liquid chromatography.

Artocarpus champeden (A. champeden) ethanol extract has been reported as antimalarial activity and prospective to be developed as phytomedicine products. The active marker compound was identical with known prenylated chalcone compound, Morachalcone A. To further develop phytomedicine products from A. champeden especially in aspects of bioavailability and pharmacokinetic, a valid, selective and sensitive analytical method becomes important to determine morachalcone A in plasma. The aim of study was to develop and validate selectivity and sensitivity of High Performance Liquid Chromatography (HPLC) method to determine morachalcone A in rabbit plasma. This method was used a RP-18 Column (250 x 4.6 mm i.d, 5 µm), under isocratic elution and acetonitrile:water (50:50 v/v) was used as mobile phase with flow rate of 1.0ml/min. Detection was carried out at 368 nm, 4-hydroxychalcone and methanol were used as internal standard and precipitant. Results showed that this HPLC method was selective with good linearity in range of 3096.774 to 154.839ng/ml. LOD and LLOQ were 89.384 and 154.839ng/ml, respectively. The mean %different was found between 2.79 to 14.33%. Intra and inter-day precision were ≤15% and recovery from this extraction method of morachalcone A and Internal Standard were 80-120%.

Antiplasmodial Activity of Isolated Polyphenols from Alectryon serratus Leaves Against 3D7 Plasmodium falciparum.

BACKGROUND: Alectryon serratus was selected from a screening program devoted to search naturally occurring antimalarial compound from plants in Alas Purwo National Park, Banyuwangi, East Java, Indonesia. The previous studies showed that ethanol extract of A. serratus leaves contains some polyphenol compounds. OBJECTIVE: This study was designed to isolate and investigate antiplasmodial activity of polyphenol compounds. MATERIAL AND METHODS: The ethanol extract of A. serratus leaves was fractioned using liquid-liquid fractionation and column chromatography. Isolated compounds were identified using High-performance liquid chromatography, ultraviolet-visible, nuclear magnetic resonance, and compared with references. The isolates were tested in vitro for antiplasmodial activity against chloroquine-sensitive 3D7 strain of Plasmodium falciparum. Thin blood smears were used to assess the levels of parasitemia and growth inhibition of the isolates. RESULT: Half maximal Inhibitory concentration of Gallic acid (1), methyl gallate (2), and kempferol-3-O-rhamnoside (3) were 0.0722 µM, 0.0128 µM, and 3.4595 µM, respectively. CONCLUSION: The results suggest that gallic acid, methyl gallate, and kempferol-3-O-rhamnoside isolated from A. serratus leaves have antiplasmodial activity and are potential to be developed as antimalarial drugs. SUMMARY: The ethanol extract of Alectryon serratus leaves was successively fractionated in CH2Cl2, EtOAc, and n-butanol. EtOAc fraction was fractionated using column chromatography and purified using preparative thin-layer chromatography (TLC). Isolates were studied for their antiplasmodial activity on parasites culture of chloroquine-sensitive 3D7 strain of Plasmodium falciparum. Parasitemia percentages, growth percentages, and inhibition percentages of each group were calculated. The half maximal inhibitory concentration (IC50) values that represent the concentration required to inhibit 50% of Plasmodium growth were calculated from a calibration curve using linear regression. The results suggest that isolates have antiplasmodial activity and are responsible in the antimalarial activity of Alectryon serratus leaves. Abbreviations Used: S.F: Subfraction, EGCG: Epigallocatechingallate, EGC: Epigallocatechin.