Limonoids from the fruits of Chisocheton erythrocarpus and their mosquito larvicidal activities

Phytochemical study of the fruits of Chisocheton erythrocarpus (Hiern) allowed the identification of eight undescribed limonoids, namely erythrocarpines O - V (1-6, 7a and 7b), along with seven known compounds. The structures of these compounds were elucidated based on spectroscopic and HRMS data, along with electronic circular dichroism to configure the absolute configuration. Erythrocarpines O and P are γ-hydroxybutenolide analogs of mexicanolide-type limonoids while erythrocarpine Q - V are phragmalin-type limonoids possessing a 1,29-oxymethylene bridge with either benzoyl or cinnamoyl moiety in their structures. Mosquito larvicidal activity revealed that crude DCM extract of C. erythrocarpus possessed a good larvicidal effect against Aedes aegypti larvae in 48 h (LC50 = 153.0 ppm). Subsequent larvicidal activity of isolated compounds indicated that erythrocarpine G (10) and 14-deoxyxyloccensin K (11) were responsible for the enhanced larvicidal effect of the extract, reporting LC50 values of 18.55 ppm and 41.16 ppm, respectively. Moreover, residual activity testing of the crude DCM extract revealed that the duration of its larvicidal effects is up to 14 days, where it maintained a 98 % larval mortality throughout the test period, under laboratory conditions.

The protective effects of Zingiber zerumbet rhizome against fevers in rats

The Zingiber zerumbet rhizomes are traditionally used to treat fever, and the in vitro inhibitory effect of ethyl acetate extract from Zingiber zerumbet rhizomes (EAEZZR) against DENV2 NS2B/NS3 (two non-structural proteins, NS2 and NS3 of dengue virus type 2) has been reported earlier. This study was carried out to establish an acute toxicity profile and evaluate the anti-fever (anti-pyretic) activities of EAEZZR in yeast-induced fever in rats. The major compound of EAEZZR, zerumbone, was isolated using chromatographic methods including column chromatography (CC) and preparative thin-layer chromatography (PTLC). Additionally, the structure of zerumbone was elucidated using nuclear magnetic resonance (NMR), liquid chromatography mass spectrometer-ion trap-time of flight (LCMS-IT-TOF), infrared (IR), and ultraviolet (UV) spectroscopy. The toxicity of EAEZZR was evaluated using Organization for Economic Cooperation and Development Test Guideline 425 (OECD tg-425) with minor modifications at concentrations EAEZZR of 2000 mg/kg, 3000 mg/kg, and 5000 mg/kg. Anti-fever effect was determined by yeast-induced fever (pyrexia) in rats. The acute toxicity study showed that EAEZZR is safe at the highest 5000 mg/kg body weight dose in Sprague Dawley rats. Rats treated with EAEZZR at doses of 125, 250, and 500 mg/kg exhibited a significant reduction in rectal temperature (TR) in the first 1 h. EAEZZR at the lower dose of 125 mg/kg showed substantial potency against yeast-induced fever for up to 2 h compared to 0 h in controls. A significant reduction of TR was observed in rats treated with standard drug aspirin in the third through fourth hours. Based on the present findings, ethyl acetate extract of Zingiber zerumbet rhizomes could be considered safe up to the dose of 5000 mg/kg, and the identification of active ingredients of Zingiber zerumbet rhizomes may allow their use in the treatment of fever with dengue virus infection.

Chemodiverse monoterpene indole alkaloids from Kopsia teoi, inhibitory potential against α-amylase, and their molecular docking studies

Diabetes mellitus stands as a metabolic ailment marked by heightened blood glucose levels due to inadequate insulin secretion. The primary aims of this investigative inquiry encompassed the isolation of phytochemical components from the bark of Kopsia teoi, followed by the assessment of their α-amylase inhibition. The phytochemical composition of the K. teoi culminated in the discovery of a pair of new indole alkaloids; which are 16-epi-deacetylakuammiline N(4)-methylene chloride (akuammiline) (1), and N(1)-methoxycarbonyl-11-methoxy-12-hydroxy-Δ14-17-kopsinine (aspidofractinine) (2), together with five known compounds i.e. kopsiloscine G (aspidofractinine) (3), akuammidine (sarpagine) (4), leuconolam (aspidosperma) (5), N-methoxycarbonyl-12-methoxy-Δ16, 17-kopsinine (aspidofractinine) (6), and kopsininate (aspidofractinine) (7). All compounds were determined via spectroscopic analyses. The in vitro evaluation against α-amylase showed good inhibitory activities for compounds 5-7 with the inhibitory concentration (IC50) values of 21.7 ± 1.2, 34.1 ± 0.1, and 30.0 ± 0.8 μM, respectively compared with the reference acarbose (IC50 = 34.4 ± 0.1 μM). The molecular docking outputs underscored the binding interactions of compounds 5-7 ranging from -8.1 to -8.8 kcal/mol with the binding sites of α-amylase. Consequently, the outcomes highlighted the anti-hyperglycemic attributes of isolates from K. teoi.

Erythrocarpines IN, new limonoids from the barks of Chisocheton erythrocarpus and their neuroprotective effects against hydrogen peroxide in NG108-15 cells

A phytochemical study on the bark of Chisocheton erythrocarpus Hiern (Meliaceae) has led to the isolation of six new phragmalin-type limonoids named erythrocarpines I - N (1-6) along with one known limonoid, erythrocarpine F (7). Their structures were fully characterized by spectroscopic methods. The pre-treatment of NG108-15 cells with 1-5, 7 (2 h) demonstrated low to good protective effects against H2O2 exposure; 1 (83.77% ± 1.84 at 12.5 μM), 2 (69.07 ± 2.01 at 12.5 μM), 3 (80.38 ± 2.1 at 12.5 μM), 4 (62.33 ± 1.95 at 25 μM),5 (58.67 ± 1.85 at 50 μM) and 7 (66.07 ± 2.03 at 12.5 μM). Interestingly, 1 and 3 demonstrated comparable protective effects to positive control epigallocatechin gallate (EGCG) with similar cell viability capacity (≈ 80%), having achieved that at lower concentration (12.5 μM) than EGCG (50 μM). Collectively, the results suggested the promising use of 1 and 3 as potential neuroprotective agents against hydrogen peroxide-induced cytotoxicity in neuronal model.

13C NMR-based dereplication using MixONat software to decipher potent anti-cholinesterase compounds in Mesua lepidota bark

A bio-assay guided fractionation strategy based on cholinesterase assay combined with 13C NMR-based dereplication was used to identify active metabolites from the bark of Mesua lepidota. Eight compounds were identified with the aid of the 13C NMR-based dereplication software, MixONat, i.e., sitosterol (1), stigmasterol (2), α-amyrin (3), friedelin (6), 3β-friedelinol (7), betulinic acid (9), lepidotol A (10) and lepidotol B (11). Further bio-assay guided isolation of active compounds afforded one xanthone, pyranojacareubin (12) and six coumarins; lepidotol A (10), lepidotol B (11), lepidotol E (13), lepidotin A (14), and lepidotin B (15), including a new Mammea coumarin, lepidotin C (16). All the metabolites showed strong to moderate butyrylcholinesterase (BChE) inhibition. Lepidotin B (15) exhibited the most potent inhibition towards BChE with a mix-mode inhibition profile and a Ki value of 1.03 µM. Molecular docking and molecular dynamics simulations have revealed that lepidotin B (15) forms stable interactions with key residues within five critical regions of BChE. These regions encompass residues Asp70 and Tyr332, the acyl hydrophobic pocket marked by Leu286, the catalytic triad represented by Ser198 and His438, the oxyanion hole (OH) constituted by Gly116 and Gly117, and the choline binding site featuring Trp82. To gauge the binding strength of lepidotin B (15) and to pinpoint pivotal residues at the binding interface, free energy calculations were conducted using the Molecular Mechanics Generalized Born Surface Area (MM-GBSA) approach. This analysis not only predicted a favourable binding affinity for lepidotin B (15) but also facilitated the identification of significant residues crucial for the binding interaction.

Malabaricones from the fruit of Myristica cinnamomea King as potential agents against Acanthamoeba castellanii

Acanthamoeba castellanii is an opportunistic free-living amoeba (FLA) pathogen which can cause fatal central nervous system (CNS) infection, granulomatous amoebic encephalitis (GAE) and potentially blinding ocular infection, Acanthamoeba keratitis (AK). Acanthamoeba species remain a challenging protist to treat due to the unavailability of safe and effective therapeutic drugs and their ability to protect themselves in the cyst stage. Natural products and their secondary metabolites play a pivotal role in drug discovery against various pathogenic microorganisms. In the present study, the ethyl acetate extract of Myristica cinnamomea King fruit was evaluated against A. castellanii (ATCC 50492), showing an IC50 of 45.102 ± 4.62 µg/mL. Previously, the bio-guided fractionation of the extract resulted in the identification of three active compounds, namely Malabaricones (A-C). The isolated and thoroughly characterized acylphenols were evaluated for their anti-amoebic activity against A. castellanii for the first time. Among tested compounds, Malabaricone B (IC50 of 101.31 ± 17.41 µM) and Malabaricone C (IC50 of 49.95 ± 6.33 µM) showed potent anti-amoebic activity against A. castellanii trophozoites and reduced their viability up-to 75 and 80 %, respectively. Moreover, both extract and Malabaricones also significantly (p < 0.05) inhibit the encystation and excystation of A. castellanii, while showed minimal toxicity against human keratinocyte cells (HaCaT cells) at lower tested concentrations. Following that, the explanation of the possible mechanism of action of purified compounds were assessed by detection of the state of chromatin. Hoechst/PI 33342 double staining showed that necrotic cell death occurred in A. castellanii trophozoites after 8 h treatment of Malabaricones (A-C). These findings demonstrate that Malabaricones B and C could serve as promising therapeutic options against A. castellanii infections.

Phytoconstituents of Endiandra kingiana; antidiabetic effects and molecular docking studies on alpha-amylase and alpha-glucosidase

Phytochemical investigation on the bark of E. kingiana plant afforded ten compounds, including six polyketides namely kingianin A 1, kingianin B 2, kingianin E 3, kingianin F 4, kingianin K 5 and kingianin L 6, three endiandric acids; kingianic acid A 7, tsangibeilin B 8 and endiandric acid M 9, and one sesquiterpene; daibuoxide 10. All compounds were separated as racemic mixture by recycling high-performance liquid chromatography (RHPLC), except for daibuoxide. Their structures were elucidated by detailed spectroscopic and comparative literature data analysis. This is the first report on the presence of the sesquiterpene; daibuoxide in Endiandra genus. In vitro enzymatic bio-evaluation of the isolated compounds against α-amylase and α-glucosidase showed that 4 demonstrated the best α-amylase and α-glucosidase inhibitory activity with IC50 values of 181.54 ± 6.27 µg/mL and 237.87 ± 0.07 µg/mL, respectively. In addition, molecular docking analysis confirmed the α-amylase and α-glucosidase inhibitory activities demonstrated by 4.

N-Methyl Costaricine and Costaricine, Two Potent Butyrylcholinesterase Inhibitors from Alseodaphne pendulifolia Gamb

Studies have been conducted over the last decade to identify secondary metabolites from plants, in particular those from the class of alkaloids, for the development of new anti-Alzheimer's disease (AD) drugs. The genus Alseodaphne, comprising a wide range of alkaloids, is a promising source for the discovery of new cholinesterase inhibitors, the first-line treatment for AD. With regard to this, a phytochemical investigation of the dichloromethane extract of the bark of A. pendulifolia Gamb. was conducted. Repeated column chromatography and preparative thin-layer chromatography led to the isolation of a new bisbenzylisoquinoline alkaloid, N-methyl costaricine (1), together with costaricine (2), hernagine (3), N-methyl hernagine (4), corydine (5), and oxohernagine (6). Their structures were elucidated by the 1D- and 2D-NMR techniques and LCMS-IT-TOF analysis. Compounds 1 and 2 were more-potent BChE inhibitors than galantamine with IC₅₀ values of 3.51 ± 0.80 µM and 2.90 ± 0.56 µM, respectively. The Lineweaver-Burk plots of compounds 1 and 2 indicated they were mixed-mode inhibitors. Compounds 1 and 2 have the potential to be employed as lead compounds for the development of new drugs or medicinal supplements to treat AD.

Phytochemical Evaluation and Cytotoxic Activities of Stem Bark and Leaf Extracts of Mesua assamica

Natural products and their derivatives have historically been invaluable as a source of therapeutic agents. The Mesua (Calophyllaceae) has been known to produce various new chemical compounds of medicinal values. Some Mesua species have yielded new potential anticancer agents that are important to the pharmaceutical industry. In this research, phytochemical constituents, antioxidant and cytotoxic activities of different solvent extracts of Mesua assamica stem bark and leaves were evaluated. The stem bark and leaves of M. assamica were successively extracted in hexane, ethyl acetate and methanol. Qualitative phytochemical analysis showed that most of the M. assamica extracts consist of important phytochemicals, namely, anthraquinones, terpenoids, flavonoids, saponins, tannins, phlobatannins, alkaloids, cardiac glycosides, glycosides, decreasing sugars, steroids, lipids, phenols, coumarins, carbohydrates, proteins, and betacyanin indicating its potential for medicinal use. Quantitative determination of total phenolics, total flavonoids, and in vitro antioxidant activities through DPPH assay of M. assamica extracts have been achieved by utilizing colorimetric methods. In vitro cytotoxic evaluation through MTT assay induction against human breast MCF-7 cancer cell lines exhibited that hexane extracts were found to have IC50 value below 30 μg/mL and conferred effectiveness in inducing cell death MCF-7. The diversity of phytochemicals present suggests that the stem bark and leaves of M. assamica could serve as a supply of potentially valuable medications. Exploiting the plant's pharmacological qualities will necessitate more study on the isolation, purification, and identification of bioactive components.

Synthesis, characterization, anti-mycobacterial activity and in silico study of new 2,5-disubstituted-1,3,4-oxadiazole derivatives

A series of new 2,5-disubstituted-1,3,4-oxadiazole derivatives (5a-j and 6a-j) have been designed and synthesized in four-steps. Sixteen compounds among the twenty compounds are reported for the first time. The compounds were characterized and confirmed by the FTIR, 1D- and 2D-NMR and HRMS analyses, and were tested against Mycobacterium smegmatis and Mycobacterium tuberculosis H37Ra. Compound 5d was the most active against M. smegmatis with MIC value of 25 µM, and exhibited cidal activity with MBC of 68 µM, respectively. The time-kill assay showed the good killing rate at 77% with the combination of isoniazid (INH). In addition, checkboard assay confirmed the interaction of compound 5d was categorised as additive. Docking simulation has been performed to position 5d into the pantothenate synthetase active site with binding free energy value -8.6 kcal mol-1. It also occupied the same active site as that of standard native ligand with similar interactions, which clearly indicate their potential as pantothenate synthetase inhibitor.

(R)-13aα-Densiindolizidine, A New Phenanthroindolizidine Alkaloid From Cryptocarya densiflora Blume (Lauraceae) and Molecular Docking Against SARS-CoV-2

Cryptocarya densiflora Blume (Lauraceae) is an evergreen tree widely distributed throughout the hills and mountain forests up to 1500 m in Malaysia and Indonesia. The plant has been reported to contain phenanthroindolizidine-type of alkaloids. In the present work, a new phenanthroindolizidine alkaloid named ( R)-13a α-densiindolizidine, was isolated from the dichloromethane (DCM) extract of the leaves. The structure of the alkaloid was established based on 1D and 2D nuclear magnetic resonance (NMR) and liquid chromatography mass spectrometry-ion trap-time of flight (LCMS-IT-TOF) analysis. ( R)-13a α-densiindolizidine displayed binding interactions with crucial amino acid residues in the active sites ofsevere acute respiratory syndrome coronavirus 2 Mpro (SARS-CoV-2 Mpro) and RNA-dependent protease (RdRp) in silico, whilst fulfilling theabsorption, distribution, metabolism, excretion, and toxicity (ADMET) criteria and Lipinsky's rule, thus revealing its potential as a lead compound.

(+)-Neocadambine A and (-)-nauclederine Isolated from the Bark of Neolamarckia cadamba (Rubiaceae) as Natural Advanced Glycation End Products (AGEs) Inhibitors

The phytochemical study on the dichloromethane extract of Neolamarckia cadamba (Roxb.) Bosser has afforded two indole alkaloids, (+)-neocadambine A (1) and (-)-nauclederine (2). Their structures were confirmed by extensive spectroscopic analysis and by comparing with the reported data. (+)-Neocadambine A (1) and (-)-nauclederine (2) exhibited potent inhibition activity of advanced glycation end products (AGEs) with IC50 values of 1.2 and 0.95 mM, respectively, while the latter was almost two times more potent than the standard, aminoguanidine (1.8 mM). This is the first report on the compounds isolated from this plant with AGEs inhibition activity. In addition, (-)-nauclederine (2) was isolated for the first time in the genus of Neolamarckia. Complete 1H-NMR and 13C-NMR of compound 2 were also reported.

A Nortriterpenoid and Steroid from the Stem Bark of Aglaia angustifolia Miq (Meliaceae)

A nortriterpenoid, 3-epi-cabraleahydroxylactone (1) and a steroid, stigma-4-en-3-on (2) were isolated from the n-hexane extract of  stem bark of Aglaia angustifolia Miq. Compound (2) was isolated for the first time from this Genus. The structure of both compounds were identified by spectroscopic datas including one and two-dimensional NMR as well as infrared spectrum, high-resolution mass spectrometric analysis and by comparing with those spectral data previously.

Synthesis, Characterization, Anti-Mycobacterial Activity and In Silico Study of New 2,5-disubstituted-1,3,4-oxadiazole derivatives.. [DOI: 10.21203/rs.3.rs-1651702/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

A series of new 2,5-disubstituted-1,3,4-oxadiazole derivatives (5a-j and 6a-j) have been designed and synthesized in four-steps. sixteen compounds among the twenty compounds are reported for the first time. The compounds were characterized and confirmed by the FTIR, 1D- and 2D-NMR and HRMS analyses, and were tested against Mycobacterium smegmatis and Mycobacterium tuberculosis H37Ra. Compound 5d was the most active against M. Smegmatis with MIC value of 25 µM, and exhibited cidal activity with MBC of 68 µM, respectively. The time-kill assay showed the good killing rate at 77% with the combination of isoniazid (INH). In addition, checkboard assay confirmed the interaction of compound 5d was categorised as additive. Docking simulation has been performed to position 5d into the pantothenate synthetase active site with binding free energy value –8.6 kcal mol-1. It also occupied the same active site as that of standard native ligand with similar interactions, which clearly indicate their potential as pantothenate synthetase inhibitor.

Analgesic, anti-inflammatory and NF-κB inhibitory activity of aerial parts of Cestrum diurnum

Background

Cestrum diurnum L. (Solanaceae), locally known as buno-Hasnahena, is widely used in different traditional medicinal practices to treat pain, burn, swelling and related disorders. Adequate evidence is not available to support its medicinal properties for further use and drug development. Present study was designed to evaluate its traditional use in pain and inflammation with further characterisation of its chemical constituents through liquid chromatography-mass spectroscopic (LC-MS) analysis.

Methods

Antinociceptive and analgesic potential of methanol extract of the aerial parts of C. diurnum was carried out using carrageenan induced paw oedema and formalin induced paw licking test in mice at the oral doses of 150 and 300 mg/kg body weight. Inhibition of the inflammatory mediator nuclear factor kappa B (NF-κB) was evaluated by tumour necrosis factor α (TNF-α) induced NF-κB activation assay in macrophage cells at the concentration of 100 μg/ml. LC-MS analysis of the extract was performed to characterise the active component responsible for bioactivities.

Results

The extract significantly inhibited (p < 0.05) carrageenan induced paw oedema at both doses tested and the effect persisted throughout the entire experimental period of 3 h with the highest activity (50% inhibition) observed at 3rd h. Further, the extract significantly inhibited (p < 0.05) formalin induced paw licking both in the early and late phase at the aforementioned dose levels. The extract also downregulated the expression of NF-κB p65 protein in the TNF-α induced NF-κB activation assay. LC-MS analysis of the extract indicated the presence of some important secondary metabolites including nicotine, nornicotine, ursolic acid, vitamin D3 and its derivatives.

Conclusions

The results of this study supported the folkloric uses of the plant in pain and inflammations. The insights and observations suggest the action might involve downregulation of NF-κB p65 protein expression and/or inhibition of autacoids (histamine, serotonin, prostaglandin).

Anti-Hyperglycemic Activities, Molecular Docking and Structure-Activity Relationships (SARs) Studies of Endiandric Acids and Kingianins from Endiandra kingiana

Diabetes has become a severe chronic disease worldwide with patients significantly increasing daily. Due to the side effects of insulin and oral hypoglycaemic agents employed in diabetes treatment, scientists are working hard to develop alternative approaches from natural plants that inhibit α-amylase and α-glucosidase. Consequently, by performing a phytochemical analysis on the bark of Endiandra kingiana, the present study isolated 11 cyclic polyketides. Analyses with one-dimensional and two-dimensional nuclear magnetic resonance (1D- and 2D-NMR), highresolution electron ionization mass spectrometry (HRESIMS), and comparison with previous literature confirmed the compounds characteristics. Subsequently, the compounds were screened for in vitro α-amylase and α-glucosidase inhibiting activities. Compounds 9 and 2 exhibited potent inhibition towards α-amylase at 0.0008903 ± 0.5 and 0.02 ± 0.3 mg mL−1 of half-maximal inhibitory concentration (IC50) values, respectively. In the α-glucosidase inhibition assay, compounds 10 and 5 demonstrated good inhibition with IC50 values of 0.11 ± 0.08 and 0.14 ± 0.05 mg mL−1, respectively. The molecular docking examination demonstrated that the compounds adhered to the active sites on the C-terminal of the human pancreatic α-amylase (Protein Data Bank Identification (PDB ID): 2QV4, resolution: 1.97 Å) and maltase-glucoamylase (MGAM) (PDB ID: 3TOP, resolution: 2.88 Å), agreeing with α-amylase and α-glucosidase enzymes inhibitory reactions.

Topical Administration Effect of Sargassum duplicatum and Garcinia mangostana Extracts Combination on Open Wound Healing Process in Diabetic Mice

This research aimed to determine the topical administration effect of the combination of Sargassum duplicatum and Garcinia mangostana extracts to ameliorate diabetic open wound healing. The study used 24 adult males of Mus musculus (BALB/c strain, 3-4 months, 30-40 g). They were divided into normal control groups (KN) and diabetic groups. The diabetic group was streptozotocin-induced and divided further into three treatment groups: the diabetic control group (KD), the S. duplicatum treatment group (PA), and the combination of S. duplicatum and G. mangostana treatment group (PAM). The dose of treatment was 50 mg/kg of body weight. Each group was divided into three treatment durations, which were 3 days, 7 days, and 14 days. The wound healing process was determined by wound width, the number of neutrophils, macrophages, fibroblasts, fibrocytes, and collagen density. Histological observation showed that the topical administration of combination extracts increased the re-epithelialization of the wounded area, fibroblasts, fibrocytes, and collagen synthesis. The topical administration of combination extracts also decreased the number of neutrophils and macrophages. This study concluded that the topical administration of the combination of S. duplicatum and G. mangostana extracts improved the open wound healing process in diabetic mice.

α-Amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory effects of Melicope latifolia bark extracts and identification of bioactive constituents using in vitro and in silico approaches

CONTEXT

Melicope latifolia (DC.) T. G. Hartley (Rutaceae) was reported to contain various phytochemicals including coumarins, flavonoids, and acetophenones.

OBJECTIVE

This study investigates the antidiabetic and antioxidant effects of M. latifolia bark extracts, fractions, and isolated constituents.

MATERIALS AND METHODS

Melicope latifolia extracts (hexane, chloroform, and methanol), fractions, and isolated constituents with varying concentrations (0.078-10 mg/mL) were subjected to in vitro α-amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory assay. Molecular docking was performed to study the binding mechanism of active compounds towards α-amylase and DPP-4 enzymes. The antioxidant activity of M. latifolia fractions and compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene bleaching assays.

RESULTS

Melicope latifolia chloroform extract showed the highest antidiabetic activity (α-amylase IC₅₀: 1464.32 μg/mL; DPP-4 IC₅₀: 221.58 μg/mL). Fractionation of chloroform extract yielded four major fractions (CF₁-CF₄) whereby CF₃ showed the highest antidiabetic activity (α-amylase IC₅₀: 397.68 μg/mL; DPP-4 IC₅₀: 37.16 μg/mL) and resulted in β-sitosterol (1), halfordin (2), methyl p-coumarate (3), and protocatechuic acid (4). Isolation of compounds 2-4 from the species and their DPP-4 inhibitory were reported for the first time. Compound 2 showed the highest α-amylase (IC₅₀: 197.53 μM) and β-carotene (88.48%) inhibition, and formed the highest number of molecular interactions with critical amino acid residues of α-amylase. The highest DPP-4 inhibition was exhibited by compound 3 (IC₅₀: 911.44 μM).

DISCUSSION AND CONCLUSIONS

The in vitro and in silico analyses indicated the potential of M. latifolia as an alternative source of α-amylase and DPP-4 inhibitors. Further pharmacological studies on the compounds are recommended.

Biological and Analytical Investigations of Alpha-Glucosidase Inhibitory and Anti-Oxidant Activities on Selected Malaysian Medicinal Plants

This study was performed to establish anti-diabetic and anti-oxidant properties, and to carry out phytochemical analysis of selected local plants which are traditionally used as medicinal plants. Local plants involved in this study were Lawsonia inermis, Punica granatum, Dryobalanops aromatica, Ziziphus mauritiana, and Ocimum basilicum. Solvent extraction was performed using maceration method with solvents of increasing polarity. Alpha-glucosidase inhibition assay was performed on all extracts to ascertain their anti-diabetic potentials. The extracts were screened for antioxidant activity using anti-oxidant assays (FRAP, DPPH, TAOC, ABTS, and BCB) and quantitative phytochemical analyses (TPC and TFC). Chemical profiling using LCMS and GCMS was performed on extracts with high biological activities. Methanol extracts of D. aromatica bark and leaves showed the most potent inhibition of alpha-glucosidase with IC50 values of 0.63 ± 0.03 µg/mL and 0.98 ± 0.02 µg/mL, respectively. Both extracts exhibited similar anti-oxidant activity on all five assays and possessed high phenolic contents with values of 266.79 and 261.69 GAE, respectively. The results obtained suggested that amongst the selected plants studied, D. aromatica showed high anti-oxidant activity and anti-diabetic activity (via inhibition of alpha-glucosidase). This is the first report that highlights the anti-diabetic potential of D. aromatica.

Cytotoxic triterpenoids from the stem bark of Aglaia angustifolia

A seco-apotirucallane-type triterpenoid, namely angustifolianin (1), along with three dammarane-type triterpenoids, (20S, 24S)-epoxy-dammarane-3β,25-diol (2), 3-epi-cabraleahydroxylactone (3), and cabralealactone (4), were isolated from the stem bark of Aglaia angustifolia Miq. The Chemical structure of the new compounds was elucidated on the basis of spectroscopic data. All of the compounds were evaluated for their cytotoxic effects against MCF-7 breast cancer cells. Among those compounds, angustifolianin (1) showed strongest cytotoxic activity with an IC₅₀ value of 50.5 μg/ml.

Oxygen radical antioxidant capacity (ORAC) and antibacterial properties of Melicope glabra bark extracts and isolated compounds

Melicope glabra (Blume) T. G. Hartley from the Rutaceae family is one of the richest sources of plant secondary metabolites, including coumarins and flavanoids. This study investigates the free radical scavenging and antibacterial activities of M. glabra and its isolated compounds. M. glabra ethyl acetate and methanol extracts were prepared using the cold maceration technique. The isolation of compounds was performed with column chromatography. The free radical scavenging activity of the extracts and isolated compounds were evaluated based on their oxygen radical absorbance capacity (ORAC) activities. The extracts and compounds were also subjected to antibacterial evaluation using bio-autographic and minimal inhibitory concentration (MIC) techniques against two oral pathogens, Enterococcus faecalis and Streptococcus mutans. Isolation of phytoconstituents from ethyl acetate extract successfully yielded quercetin 3, 5, 3’-trimethyl ether (1) and kumatakenin (2), while the isolation of the methanol extract resulted in scoparone (3), 6, 7, 8-trimethoxycoumarin (4), marmesin (5), glabranin (6), umbelliferone (7), scopoletin (8), and sesamin (9). The study is the first to isolate compound (1) from Rutaceae plants, and also the first to report the isolation of compounds (2–5) from M. glabra. The ORAC evaluation showed that the methanol extract is stronger than the ethyl acetate extract, while umbelliferone (7) exhibited the highest ORAC value of 24 965 μmolTE/g followed by glabranin (6), sesamin (9) and scopoletin (8). Ethyl acetate extract showed stronger antibacterial activity towards E. faecalis and S. mutans than the methanol extract with MIC values of 4166.7 ± 1443.4 μg/ml and 8303.3 ± 360.8 μg/ml respectively. Ethyl acetate extract inhibited E. faecalis growth, as shown by the lowest optical density value of 0.046 at a concentration of 5.0 mg/mL with a percentage inhibition of 95%. Among the isolated compounds tested, umbelliferone (7) and sesamin (9) exhibited promising antibacterial activity against S. mutans with both exhibiting MIC values of 208.3 ± 90.6 μg/ml. Findings from this study suggests M. glabra as a natural source of potent antioxidant and antibacterial agents.

Natural DENV-2 NS2B/NS3 protease inhibitors from Myristica cinnamomea King

The NS2B/NS3 protease is crucial for the pathogenesis of the DENV. Therefore, the inhibition of this protease is considered to be the key strategy for the development of new antiviral drugs. In the present study, malabaricones C (3) and E (4), acylphenols from the fruits of Myristica cinnamomea King, have been respectively identified as moderate (27.33 ± 5.45 μM) and potent (7.55 ± 1.64 μM) DENV-2 NS2B/NS3 protease inhibitors, thus making this the first report on the DENV-2 NS2B/NS3 protease inhibitory activity of acylphenols. Based on the molecular docking studies, compounds 3 and 4 both have π-π interactions with Tyr161. While compound 3 has hydrogen bonding interactions with Gly151, Gly153 and Tyr161, compound 4 however, forms hydrogen bonds with Ser135, Asp129, Phe130 and Ile86 instead. The results from the present study suggests that malabaricones C (3) and E (4) could be employed as lead compounds for the development of new dengue antivirals from natural origin.

Giganteone A and malabaricone C as potential pharmacotherapy for diabetes mellitus

The use of antidiabetic agents which control glycemic levels in the blood and simultaneously inhibit oxidative stress is an important strategy in the prevention of Diabetes Mellitus and its complications. In our previous study, malabaricone C (3) and its dimer, giganteone A (5) exhibited significant DPPH free radical scavenging activities which were lower than the activity of the positive control, ascorbic acid. These compounds were evaluated for their α-glucosidase inhibitory activities at different concentrations (0.02-2.5 mM) in the present study. Compounds 3 (IC₅₀ 59.61 µM) and 5 (IC₅₀ 39.52 µM) were identified as active alpha-glucosidase inhibitors, each respectively being 24 and 37 folds more potent than the standard inhibitor, acarbose. Based on the molecular docking studies, compounds 3 and 5 docked into the active site of the α-glucosidase enzyme, forming mainly hydrogen bonds in the active site.

Cytotoxic constituent of Melicope latifolia (DC.) T. G. Hartley

An undescribed conjugated sesquiterpene, amelicarin (1), together with nine known compounds (2-10) were isolated for the first time from Melicope latifolia. Their structures were elucidated by extensive NMR spectroscopic and mass spectrometric methods. The conjugated sesquiterpene possesses a unique 6/6/9/4-ring fused tetracyclic skeleton. The proposed biosynthesis pathway of 1 consist of three reactions steps: (1) polyketide formation, (2) cyclisation and (3) addition to form the conjugated sesquiterpenoid as final metabolite. Out of the ten isolated metabolites, amelicarin (1) showed activity against 4 cancerous cell lines namely SK-MEL skin cancer, KB oral cancer, BT-549 breast cancer, and SK-OV-3 ovarian cancer with IC₅₀ values between 15 and 25 µg/mL.

Synthesis of 1ʹ-acetoxychavicol acetate (ACA) analogues and their inhibitory activities against methicillin-resistant Staphylococcus aureus

A series of 1ʹ-acetoxychavicol acetate analogues were synthesised and evaluated for their antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) using broth microdilution technique. The minimum inhibitory concentration (MIC) was used to determine whether the compounds had potential as inhibitory agents against the MRSA ATCC 43300, and the compounds with antimicrobial potential (<2000 μg ml–1) were tested for minimum bactericidal concentration (MBC). Based on this assay, compound 1 exhibited potent antimicrobial activity with MIC value of 250 μg ml–1. Meanwhile, compounds 2 and 13 showed the moderate activity with MIC values of 500 μg ml–1, respectively.

Chemicals Constituents Isolated from Cultivate Alpinia conchigera Griff. and Antimicrobial Activity

Alpinia conchigera Griff. is a plant species from the family Zingiberaceae. Coloquially known as wild ginger, Alpinia conchigera Griff. is used as food condiment and for traditional treatment of skin diseases. Isolation studies to identify bioactive compounds of rhizomes of Alpinia conchigera yielded seven compounds; 1'S-1'-acetoxychavicol acetate (1), trans-p-coumaryl diacetate (2), p-hydroxycinnamyl acetate (3), 1'S-1'-hydroxychavicol acetate (4) p-hydroxybenzaldehyde (5), stigmasterol (6) and β-sitosterol (7). Compounds 1, 2 and 5 were evaluated for antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). Among the compounds tested, Compound 1 showed good antimicrobial activity against the strain of MRSA with minimum inhibition concentration (MIC) value of 0.5 mg/mL. Meanwhile, Compounds 2 and 5 exhibited moderate activity with MIC value between 1.0 and 2.0 mg/mL. These findings indicate antimicrobial potential of 1'S-1'-acetoxychavicol acetate (1), compound derived from rhizome of Alpinia conchigera Griff. against MRSA, which warrant further investigation.

Targeting MHC Regulation Using Polycyclic Polyprenylated Acylphloroglucinols Isolated from Garcinia bancana

Modulation of major histocompatibility complex (MHC) expression using drugs has been proposed to control immunity. Phytochemical investigations on Garcinia species have allowed the isolation of bioactive compounds such as polycyclic polyprenylated acylphloroglucinols (PPAPs). PPAPs such as guttiferone J (1), display anti-inflammatory and immunoregulatory activities while garcinol (4) is a histone acetyltransferases (HAT) p300 inhibitor. This study reports on the isolation, identification and biological characterization of two other PPAPs, i.e., xanthochymol (2) and guttiferone F (3) from Garcinia bancana, sharing structural analogy with guttiferone J (1) and garcinol (4). We show that PPAPs 1-4 efficiently downregulated the expression of several MHC molecules (HLA-class I, -class II, MICA/B and HLA-E) at the surface of human primary endothelial cells upon inflammation. Mechanistically, PPAPs 1-4 reduce MHC proteins by decreasing the expression and phosphorylation of the transcription factor STAT1 involved in MHC upregulation mediated by IFN-γ. Loss of STAT1 activity results from inhibition of HAT CBP/p300 activity reflected by a hypoacetylation state. The binding interactions to p300 were confirmed through molecular docking. Loss of STAT1 impairs the expression of CIITA and GATA2 but also TAP1 and Tapasin required for peptide loading and transport of MHC. Overall, we identified new PPAPs issued from Garcinia bancana with potential immunoregulatory properties.

Pro-apoptotic carboxamide analogues of natural fislatifolic acid targeting Mcl-1 and Bcl-2

A library of 26 novel carboxamides deriving from natural fislatifolic acid has been prepared. The synthetic strategy involved a bio-inspired Diels-Alder cycloaddition, followed by functionalisations of the carbonyl moiety. All the compounds were evaluated on Bcl-xL, Mcl-1 and Bcl-2 proteins. In this series of cyclohexenyl chalcone analogues, six compounds behaved as dual Bcl-xL/Mcl-1 inhibitors in micromolar range and one exhibited sub-micromolar affinities toward Mcl-1 and Bcl-2. The most potent compounds evaluated on A549 and MCF7 cancer cell lines showed moderate cytotoxicities.

Corrosion inhibition on mild steel in 1 M HCl solution byCryptocarya nigraextracts and three of its constituents (alkaloids)

Corrosion inhibition effect of the crude extracts (hexane, dichloromethane, methanol) from the bark of Cryptocarya nigra and three alkaloids named N-methylisococlaurine 1, N-methyllaurotetanine 2 and atherosperminine 3 isolated from the Cryptocarya nigra dichloromethane extract (CNDE) were investigated for mild steel corrosion in 1 M HCl solution. An electrochemical impedance study showed that CNDE and 2 reduced the corrosion significantly through a charge transfer mechanism with inhibition efficiency of 91.05% and 88.05%, respectively. Potentiodynamic polarization data indicated that CNDE acted through anodic type inhibition while 2 was a mixed type inhibitor with predominant anodic effectiveness. ΔG_ads values calculated from the Langmuir adsorption isotherm plots for CNDE (−28.2 kJ mol⁻¹) and 2 (−13.2 kJ mol⁻¹) suggested that they adsorbed on the mild steel surface via a physisorption mechanism. Scanning electron microscopy micrographs and elemental composition studies confirmed the formation of a protective film over the metal surface. Wastewater quality parameters of all the inhibitors demonstrated good biodegradability as their values were within the permissible limits to discharge for irrigation and horticultural uses.

Staggered and systematic arrangement of N-methyllaurotetanine 2 on the MS surface.

Absolute Configuration of Alkaloids from Uncaria longiflora through Experimental and Computational Approaches

The structure elucidation of three new alkaloids named isoformosaninol (1), formosaninol (2), and longiflorine (3), isolated from the leaves of Uncaria longiflora var. pteropoda (Miq.) Ridsdale, along with their biosynthetic pathways are discussed. Their absolute structures were determined through a combination of physical data interpretation and quantum chemical calculations using the time-dependent density functional theory (TDDFT) method.

Anti-Cancer Effects of Synergistic Drug-Bacterium Combinations on Induced Breast Cancer in BALB/c Mice

Cancer development and progression are extremely complex due to the alteration of various genes and pathways. In most cases, multiple agents are required to control cancer progression. The purpose of this study is to investigate, using a mouse model, the synergistic interactions of anti-cancer agents, 1'-S-1'-acetoxychavicol acetate (ACA), Mycobacterium indicus pranii (MIP), and cisplatin (CDDP) in double and triple combinations to treat chemo-sensitize and immune-sensitize breast cancer. Changes in tumor volume and body weight were monitored. Organs were harvested and stained using hematoxylin-eosin for histopathological assessment. Milliplex enzyme-linked immunosorbent assay (ELISA) was performed to determine cytokine levels, while immunohistochemistry (IHC) was conducted on tumor biopsies to verify systemic drug effects. In vivo mouse models showed tumor regression with maintenance of regular body weight for all the different treatment regimens. IHC results provided conclusive evidence indicating that combination regimens were able to down-regulate nuclear factor kappa-B activation and reduce the expression of its regulated pro-inflammatory proteins. Reduction of pro-inflammatory cytokines (e.g., IL-6, TNF-α, and IFN-ɣ) levels were observed when using the triple combination, which indicated that the synergistic drug combination was able to significantly control cancer progression. In conclusion, ACA, MIP, and CDDP together serve as promising candidates for further development and for subsequent clinical trials against estrogen-sensitive breast cancer.

Goniolanceolatins A-H, Cytotoxic Bis-styryllactones from Goniothalamus lanceolatus

Eight new bis-styryllactones, goniolanceolatins A-H (1-8), possessing a rare α,β-unsaturated δ-lactone moiety with a (6S)-configuration, were isolated from the CH₂Cl₂ extract of the stembark and roots of Goniothalamus lanceolatus Miq., a plant endemic to Malaysia. Absolute structures were established through extensive 1D- and 2D-NMR data analysis, in combination with electronic dichroism (ECD) data. All of the isolates were evaluated for their cytotoxicity against human lung and colorectal cancer cell lines. Compounds 2 and 4 showed cytotoxicity, with IC₅₀ values ranging from 2.3 to 4.2 μM, and were inactive toward human noncancerous lung and colorectal cells. Compounds 1, 3, 6, 7, and 8 showed moderate to weak cytotoxicity. Docking studies of compounds 2 and 4 showed that they bind with EGFR tyrosine kinase and cyclin-dependent kinase 2 through hydrogen bonding interactions with the important amino acids, including Lys721, Met769, Asn818, Arg157, Ile10, and Glu12.

Malabaricone C as Natural Sphingomyelin Synthase Inhibitor against Diet-Induced Obesity and Its Lipid Metabolism in Mice

The interaction between natural occurring inhibitors and targeted membrane proteins could be an alternative medicinal strategy for the treatment of metabolic syndrome, notably, obesity. In this study, we identified malabaricones A-C and E (1-4) isolated from the fruits of Myristica cinnamomea King as natural inhibitors for sphingomyelin synthase (SMS), a membrane protein responsible for sphingolipid biosynthesis. Having the most promising inhibition, oral administration of compound 3 exhibited multiple efficacies in reducing weight gain, improving glucose tolerance, and reducing hepatic steatosis in high fat diet-induced obesity mice models. Liver lipid analysis revealed a crucial link between the SMS activities of compound 3 and its lipid metabolism in vitro and in vivo. The nontoxic nature of compound 3 makes it a suitable candidate in search of drugs which can be employed in the treatment and prevention of obesity.

A new antiplasmodial sterol from Indonesian marine sponge, Xestospongia sp

A new antimalarial sterol, kaimanol (1), along with a known sterol, saringosterol (2) was isolated from the Indonesian Marine sponge, Xestospongia sp. The chemical structure of the new compound was determined on the basis of spectroscopic evidences and by comparison to those related compounds previously reported. Isolated compounds, 1 and 2 were evaluated for their antiplasmodial effect against Plasmodium falciparum 3D7 strains. Compounds 1 and 2 exhibited antiplasmodial activity with IC₅₀ values of 359 and 0.250 nM, respectively.

Dengue protease inhibition activity of selected Malaysian medicinal herbs

Dengue fever is one of major health problem around the world including Malaysia. It is caused by the arthropode-borne flavivirus and transmitted by the bite of the Aedes aegypti or Aedes albopictus mosquito infected with one of the four dengue virus serotypes (DENV-1, DENV-2, DENV-3, or DENV-4). In this study, a screening exercise of various Malaysian medicinal plants showed that the extracts of Lawsonia inermis, Dryobalanops aromatica, Punica granatum, Zizyphus jujuba Lam. and Zingiber zerumbet exhibited potent inhibitory activity against NS2B-NS3 serine protease. The methanol extracts of Dryobalanops aromatica showed inhibition of 99.70 % at concentration of 200 µg/mL with IC₅₀ value of 0.30 ± 0.16 µg/mL.

Molecular Insight and Mode of Inhibition of α-Glucosidase and α-Amylase by Pahangensin A from Alpinia pahangensis Ridl

The inhibition of carbohydrate-hydrolyzing enzymes in human digestive organs is crucial in controlling blood sugar levels, which is important in treating type 2 diabetes. In the current study, pahangensin A (1), a bis-labdanic diterpene characterized previously in the rhizomes of Alpinia pahangensis Ridl., was identified as an active dual inhibitor for α-amylase (IC₅₀ =114.80 μm) and α-glucosidase (IC₅₀ =153.87 μm). This is the first report on the dual α-amylase and α-glucosidase inhibitory activities of a bis-labdanic diterpene. The Lineweaver-Burk plots of compound 1 indicate that it is a mixed-type inhibitor with regard to both enzymes. Based on molecular docking studies, compound 1 docked in a non-active site of both enzymes. The dual inhibitory activity of compound 1 makes it a suitable natural alternative in the treatment of type 2 diabetes.

Triterpenoids from the Bark of Aglaia glabrata and their In vitro Effects on P-388 Murine Leukemia Cells

Four dammarane-type triterpenoids, dammardienon (1), aglaiabbreviatin E (2), dammar-20,25-dien-3b,24-diol (3) and dammar-24-en-3b,20-diol (4) were isolated from methanolic extract of the bark of Aglaia glabrata. The structures of all triterpenoids were elucidated by 1D-, 2D-NMR, and comparison with previously reported data. All triterpenoids were applied into in vitro bioassay against P-388 murine leukemia cell. Dammar-24-en-3b,20-diol (4) has cytotoxic activity with IC50 value of 9.45 mM towards P-388 murine leukemia cell lines.

Laevifins A-G, clerodane diterpenoids from the Bark of Croton oblongus Burm.f

A phytochemical investigation of the stem barks of the Malaysian Croton oblongus Burm.f. (Syn. Croton laevifolius Blume) (Euphorbiaceae) yielded seven previously undescribed ent-neo-clerodane diterpenoids, laevifins A - G and the known crovatin (3). Structures were established by a combination of spectroscopic methods including HRESIMS, NMR spectroscopy and X-ray crystallography. The absolute configuration of crovatin and laevifins A-G was established by comparison of experimental ECD and theoretical TDDFT ECD calculated spectra. This is the first report on the occurrence of the sesquiterpenoid cryptomeridiol in a Croton species. In vitro cytotoxicity assays on laevifins A, B and G showed moderate activities against the MCF-7 cancer cell line (IC₅₀ 102, 115 and 106 μM, respectively) while β-amyrin and acetyl aleuritolic acid showed good anti-inflammatory activity on the LPS-induced NF-κB translocation inhibition in RAW 264.7 cells assay with IC₅₀ values of 23.5 and 35.4 μg/mL, respectively.

Styryl Lactones from Roots and Barks Goniothalamus lanceolatus

A new styryl lactone, 5 R,6 R-5-hydroxy-6-styryltetrahydropyrane-2-one 2 was isolated from the roots of an endemic Goniothalamus lanceolatus Miq. of Sarawak, Malaysia. Furthermore, seven previously undescribed diastereomers, 5 R,6 R-5-hydroxygoniothalamin 3, 5 R,6 R-5-acetylgoniothalamin 4, 6 S,7 S,8 S-goniodiol-7-monoacetate 5, 6 S,7 S,8 S-goniodiol-8-monoacetate 6, goniofupyrone B 7, deoxygoniopypyrone B 8 and 1 S,5 S,7 R,8 S,3- endo,7- endo-(+)-8- epi-9-deoxygoniopypyrone acetate 9, along with six known styryl lactones (1, 10–15) were also isolated and characterized. 6 S-goniothalamin 1 is reported for the first time from a Goniothalamus species. 1, 11 and 12 showed cytotoxic activity against human colon and lung cancer cell lines with IC50 values ranging from 2.38–7.59 μM.

13C-NMR dereplication of Garcinia extracts: Predicted chemical shifts as reliable databases

Usually isolated from Garcinia (Clusiaceae) or Hypericum (Hypericaceae) species, some Polycyclic Polyprenylated AcylPhloroglucinols (PPAPs) have been recently reported as potential research tools for immunotherapy. Aiming at exploring the chemodiversity of PPAPs amongst Garcinia genus, a dereplication process suitable for such natural compounds has been developed. Although less sensitive than mass spectrometry, NMR spectroscopy is perfectly reproducible and allows stereoisomers distinction, justifying the development of ¹³C-NMR strategies. Dereplication requires the use of databases (DBs). To define if predicted DBs were accurate enough as dereplication tools, experimental and predicted δ_C of natural products usually isolated from Clusiaceae were compared. The ACD/Labs commercial software allowed to predict 73% of δ_C in a 1.25 ppm range around the experimental values. Consequently, with these parameters, the major PPAPs from a Garcinia bancana extract were successfully identified using a predicted DB.

Isolation of antioxidative compounds from Micromelum minutum guided by preparative thin layer chromatography-2,2-diphenyl-1-picrylhydrazyl (PTLC-DPPH) bioautography method

The application of preparative thin layer chromatography-2,2-diphenyl-1-picrylhydrazyl (PTLC-DPPH) bioautography technique successfully isolated a lignan sesamin (1), two prenylated coumarins (2 and 3) and a marmesin glycosides (4) from Micromelum minutum methanol bark extract. Compounds 2 and 3 were identified as new compounds whereas 1 and 4 were first isolated from Micromelum genus. Structural identification of all compounds were done by detailed spectroscopic analyses and comparison with literature data. Antioxidant capacities of extract, active fraction and compounds were measured based on DPPH free radical savenging activity, oxygen radical absorbance capacity (ORAC) and β-carotene bleaching. The DPPH activity of methanol extract and its fraction present the IC₅₀ values of 54.3 and 168.9 µg/mL meanwhile the β-carotene bleaching results were 55.19% and 5.75% respectively. The ORAC measurements of M. minutum extract, compounds 2 and 4 showed potent antioxidant activity with the values of 5123, 5539 and 4031 µmol TE/g respectively.

Inactivation of nuclear factor κB by MIP-based drug combinations augments cell death of breast cancer cells

Background

Drug combination therapy to treat cancer is a strategic approach to increase successful treatment rate. Optimizing combination regimens is vital to increase therapeutic efficacy with minimal side effects.

Materials and methods

In the present study, we evaluated the in vitro cytotoxicity of double and triple combinations consisting of 1′S-1′-acetoxychavicol acetate (ACA), Mycobacterium indicus pranii (MIP) and cisplatin (CDDP) against 14 various human cancer cell lines to address the need for more effective therapy. Our data show synergistic effects in MCF-7 cells treated with MIP:ACA, MIP:CDDP and MIP:ACA:CDDP combinations. The type of interaction between MIP, ACA and CDDP was evaluated based on combination index being <0.8 for synergistic effect. Identifying the mechanism of cell death based on previous studies involved intrinsic apoptosis and nuclear factor kappa B (NF-κB) and tested in Western blot analysis. Inactivation of NF-κB was confirmed by p65 and IκBα, while intrinsic apoptosis pathway activation was confirmed by caspase-9 and Apaf-1 expression.

Results

All combinations confirmed intrinsic apoptosis activation and NF-κB inactivation.

Conclusion

Double and triple combination regimens that target induction of the same death mechanism with reduced dosage of each drug could potentially be clinically beneficial in reducing dose-related toxicities.