Evaluation of antibacterial and cytotoxic activity of Artemisia nilagirica and Murraya koenigii leaf extracts against mycobacteria and macrophages

Wound healing potential and anti-inflammatory action of extracts and compounds of Myrciaria plinioides D. Legrand leaves

Wounds or chronic injuries are associated with high medical costs so, develop healing-oriented drugs is a challenge for modern medicine. The identification of new therapeutic alternatives focuses on the use of natural products. Therefore, the main goal of this study was to evaluate the healing potential and anti-inflammatory mechanism of action of extracts and the main compounds derived from Myrciaria plinioides D. Legrand leaves. The antimicrobial activity of leaf extracts was analyzed. Cell viability, cytotoxicity and genotoxicity of plant extracts and compounds were also assessed. Release of pro- and anti-inflammatory cytokines and TGF-β by ELISA, and protein expression was determined by Western Blot. The cell migration and cell proliferation of ethanol and aqueous leaf extracts and p-coumaric acid, quercetin and caffeic acid compounds were also evaluated. The aqueous extract exhibited antibacterial activity and, after determining the safety concentrations in three assays, we showed that this extract induced p38-α MAPK phosphorylation and the same extract and the p-coumaric acid decreased COX-2 and caspase-3, -8 expression, as well as reduced the TNF-α release and stimulated the IL-10 in RAW 264.7 cells. In L929 cells, the extract and p-coumaric acid induced TGF-β release, besides increasing the process of cell migration and proliferation. These results suggested that the healing properties of Myrciaria plinioides aqueous extract can be associated to the presence of phenolic compounds, especially p-coumaric acid, and/or glycosylated metabolites.

Potent anticancer activity of (Z)-3-hexenyl-β-D-glucopyranoside in pancreatic cancer cells

This current study reports, for the first time, on the potent cytotoxicity of (Z)-3-hexenyl-β-D-glucopyranoside, as well as its cellular and molecular apoptotic mechanisms against Panc1 cancer cells. The cytotoxicity of three compounds, namely (Z)-3-hexenyl-β-D-glucopyranoside (1), gallic acid (2), and pyrogallol (3), which were isolated from C. rotang leaf, was investigated against certain cancer and normal cells using the MTT assay. The cellular apoptotic activity and Panc1 cell cycle impact of compound (1) were examined through flow cytometry analysis and Annexin V-FITC cellular apoptotic assays. Additionally, RT-PCR was employed to evaluate the effect of compound (1) on the Panc1 apoptotic genes Casp3 and Bax, as well as the antiapoptotic gene Bcl-2. (Z)-3-hexenyl-β-D-glucopyranoside demonstrated the highest cytotoxic activity against Panc1 cancer cells, with an IC50 value of 7.6 µM. In comparison, gallic acid exhibited an IC50 value of 21.8 µM, and pyrogallol showed an IC50 value of 198.2 µM. However, (Z)-3-hexenyl-β-D-glucopyranoside displayed minimal or no significant cytotoxic activity against HepG2 and MCF7 cancer cells as well as WI-38 normal cells, with IC50 values of 45.8 µM, 108.7 µM, and 194. µM, respectively. (Z)-3-hexenyl-β-D-glucopyranoside (10 µM) was demonstrated to induce cellular apoptosis and cell growth arrest at the S phase of the cell cycle in Panc1 cells. These findings were supported by RT-PCR analysis, which revealed the upregulation of apoptotic genes (Casp3 and Bax) and the downregulation of the antiapoptotic gene Bcl-2. This study emphasizes the significant cellular potency of (Z)-3-hexenyl-β-D-glucopyranoside in specifically inducing cytotoxicity in Panc1 cells.

Biosynthesis and Characterization of Calcium Oxide Nanoparticles from Citrullus colocynthis Fruit Extracts; Their Biocompatibility and Bioactivities

Modern nanotechnology encompasses every field of life. Nowadays, phytochemically fabricated nanoparticles are being widely studied for their bioactivities and biosafety. The present research studied the synthesis, characterization, stability, biocompatibility, and in vitro bioactivities of calcium oxide nanoparticles (CaONPs). The CaONPs were synthesized using Citrullus colocynthis ethanolic fruit extracts. Greenly synthesized nanoparticles had an average size of 35.93 ± 2.54 nm and showed an absorbance peak at 325 nm. An absorbance peak in this range depicts the coating of phenolic acids, flavones, flavonols, and flavonoids on the surface of CaONPs. The XRD pattern showed sharp peaks that illustrated the preferred cubic crystalline nature of triturate. A great hindrance to the use of nanoparticles in the field of medicine is their extremely reactive nature. The FTIR analysis of the CaONPs showed a coating of phytochemicals on their surface, due to which they showed great stability. The vibrations present at 3639 cm^-1 for alcohols or phenols, 2860 cm^-1 for alkanes, 2487 cm^-1 for alkynes, 1625 cm^-1 for amines, and 1434 cm^-1 for carboxylic acids and aldehydes show adsorption of phytochemicals on the surface of CaONPs. The CaONPs were highly stable over time; however, their stability was slightly disturbed by varying salinity and pH. The dialysis membrane in vitro release analysis revealed consistent nanoparticle release over a 10-h period. The bioactivities of CaONPs, C. colocynthis fruit extracts, and their synergistic solution were assessed. Synergistic solutions of both CaONPs and C. colocynthis fruit extracts showed great bioactivity and biosafety. The synergistic solution reduced cell viability by only 14.68% and caused only 16% hemolysis. The synergistic solution inhibited Micrococcus luteus slightly more effectively than streptomycin, with an activity index of 1.02. It also caused an 83.87% reduction in free radicals.

Phytochemical Composition and In Vitro Antioxidant, Anti-Inflammatory, Anticancer, and Enzyme-Inhibitory Activities of Artemisia nilagirica (C.B. Clarke) Pamp

Plants have been employed in therapeutic applications against various infectious and chronic diseases from ancient times. Various traditional medicines and folk systems have utilized numerous plants and plant products, which act as sources of drug candidates for modern medicine. Artemisia is a genus of the Asteraceae family with more than 500 species; however, many of these species are less explored for their biological efficacy, and several others are lacking scientific explanations for their uses. Artemisia nilagirica is a plant that is widely found in the Western Ghats, Kerala, India and is a prominent member of the genus. In the current study, the phytochemical composition and the antioxidant, enzyme-inhibitory, anti-inflammatory, and anticancer activities were examined. The results indicated that the ethanol extract of A. nilagirica indicated in vitro DPPH scavenging (23.12 ± 1.28 µg/mL), ABTS scavenging (27.44 ± 1.88 µg/mL), H2O2 scavenging (12.92 ± 1.05 µg/mL), and FRAP (5.42 ± 0.19 µg/mL). The anti-inflammatory effect was also noticed in the Raw 264.7 macrophages, where pretreatment with the extract reduced the LPS-stimulated production of cytokines (p < 0.05). A. nilagirica was also efficient in inhibiting the activities of α-amylase (38.42 ± 2.71 µg/mL), α-glucosidase (55.31 ± 2.16 µg/mL), aldose reductase (17.42 ± 0.87 µg/mL), and sorbitol dehydrogenase (29.57 ± 1.46 µg/mL). It also induced significant inhibition of proliferation in breast (MCF7 IC50 = 41.79 ± 1.07, MDAMB231 IC50 = 55.37 ± 2.11µg/mL) and colon (49.57 ± 1.46 µg/mL) cancer cells. The results of the phytochemical screening indicated a higher level of polyphenols and flavonoids in the extract and the LCMS analysis revealed the presence of various bioactive constituents including artemisinin.

Design, Synthesis and Molecular Docking of Novel Acetophenone-1,2,3-Triazoles Containing Compounds as Potent Enoyl-Acyl Carrier Protein Reductase (InhA) Inhibitors

New medications are desperately needed to combat rising drug resistance among tuberculosis (TB) patients. New agents should ideally work through unique targets to avoid being hampered by preexisting clinical resistance to existing treatments. The enoyl-acyl carrier protein reductase InhA of M. tuberculosis is one of the most crucial targets since it is a promising target that has undergone extensive research for anti-tuberculosis drug development. A well-known scaffold for a variety of biological activities, including antitubercular activity, is the molecular linkage of a1,2,3-triazole with an acetamide group. As a result, in the current study, which was aided by ligand-based molecular modeling investigations, 1,2,3-triazolesweredesigned and synthesized adopting the CuAAC aided cycloaddition of 1-(4-(prop-2-yn-1-yloxy)phenyl)ethanone with appropriate acetamide azides. Standard spectroscopic methods were used to characterize the newly synthesized compounds. In vitro testing of the proposed compounds against the InhA enzyme was performed. All the synthesized inhibitors completely inhibited the InhA enzyme at a concentration of 10 µM that exceeded Rifampicin in terms of activity. Compounds 9, 10, and 14 were the most promising InhA inhibitors, with IC₅₀ values of 0.005, 0.008, and 0.002 µM, respectively. To promote antitubercular action and investigate the binding manner of the screened compounds with the target InhA enzyme’s binding site, a molecular docking study was conducted.

Novel Hybrid 1,2,4- and 1,2,3-Triazoles Targeting Mycobacterium Tuberculosis Enoyl Acyl Carrier Protein Reductase (InhA): Design, Synthesis, and Molecular Docking

Tuberculosis (TB) caused by Mycobacterium tuberculosis is still a serious public health concern around the world. More treatment strategies or more specific molecular targets have been sought by researchers. One of the most important targets is M. tuberculosis' enoyl-acyl carrier protein reductase InhA which is considered a promising, well-studied target for anti-tuberculosis medication development. Our team has made it a goal to find new lead structures that could be useful in the creation of new antitubercular drugs. In this study, a new class of 1,2,3- and 1,2,4-triazole hybrid compounds was prepared. Click synthesis was used to afford 1,2,3-triazoles scaffold linked to 1,2,4-triazole by fixable mercaptomethylene linker. The new prepared compounds have been characterized by different spectroscopic tools. The designed compounds were tested in vitro against the InhA enzyme. At 10 nM, the inhibitors 5b, 5c, 7c, 7d, 7e, and 7f successfully and totally (100%) inhibited the InhA enzyme. The IC50 values were calculated using different concentrations. With IC50 values of 0.074 and 0.13 nM, 7c and 7e were the most promising InhA inhibitors. Furthermore, a molecular docking investigation was carried out to support antitubercular activity as well as to analyze the binding manner of the screened compounds with the target InhA enzyme's binding site.

Mycobactin Analogues with Excellent Pharmacokinetic Profile Demonstrate Potent Antitubercular Specific Activity and Exceptional Efflux Pump Inhibition

In this study, we have designed and synthesized pyrazoline analogues that partially mimic the structure of mycobactin, to address the requirement of novel therapeutics to tackle the emerging global challenge of antimicrobial resistance (AMR). Our investigation resulted in the identification of novel lead compounds 44 and 49 as potential mycobactin biosynthesis inhibitors against mycobacteria. Moreover, candidates efficiently eradicated intracellularly surviving mycobacteria. Thermofluorimetric analysis and molecular dynamics simulations suggested that compounds 44 and 49 bind to salicyl-AMP ligase (MbtA), a key enzyme in the mycobactin biosynthetic pathway. To the best of our knowledge, these are the first rationally designed mycobactin inhibitors to demonstrate an excellent in vivo pharmacokinetic profile. In addition, these compounds also exhibited more potent whole-cell efflux pump inhibition than known efflux pump inhibitors verapamil and chlorpromazine. Results from this study pave the way for the development of 3-(2-hydroxyphenyl)-5-(aryl)-pyrazolines as a new weapon against superbug-associated AMR challenges.

Assessment of antimycobacterial activities of pure compounds extracted from Thai medicinal plants against clarithromycin-resistant Mycobacterium abscessus

Background

Infection with Mycobacterium abscessus is usually chronic and is associated with clarithromycin resistance. Increasing drug resistance is a major public-health problem and has led to the search for new antimycobacterial agents. We evaluated the antimycobacterial activity, toxicity, and synergistic effects of several plant secondary metabolites against M. abscessus.

Methods

Twenty-three compounds were evaluated for antimycobacterial activity against thirty M. abscessus clinical isolates by broth microdilution to determine their minimum inhibitory concentration (MIC) values. Toxicity was evaluated using red and white blood cells (RBCs and WBCs). The compounds were used in combination with clarithromycin to investigate the possibility of synergistic activity.

Results

Five out of twenty-three compounds (RL008, RL009, RL011, RL012 and RL013) exhibited interesting antimycobacterial activity against M. abscessus, with MIC values ranging from <1 to >128 μg/mL. These extracts did not induce hemolytic effect on RBCs and displayed low toxicity against WBCs. The five least-toxic compounds were tested for synergism with clarithromycin against seven isolates with inducible clarithromycin resistance and seven with acquired clarithromycin resistance. The best synergistic results against these isolates were observed for RL008 and RL009 (8/14 isolates; 57%).

Conclusions

This study demonstrated antimycobacterial and synergistic activities of pure compounds extracted from medicinal plants against clarithromycin-resistant M. abscessus. This synergistic action, together with clarithromycin, may be effective for treating infections and should be further studied for the development of novel antimicrobial agents.

Curry Leaf Triggers Cell Death of P. gingivalis with Membrane Blebbing

Periodontal disease has become a serious public health problem, as indicated by accumulating evidence that periodontal disease is not only a major cause of tooth loss but is also associated with various systemic diseases. The present study assessed the anti-bacterial activities of three herbal products (curry leaf, clove, and cinnamon) against Porphyomonas gingivalis, a keystone pathogen for periodontal diseases. The curry leaf extract (CLE) showed the strongest growth inhibitory activity among them, and the activity was maintained even after extensive heat treatment. Of note, while clove and cinnamon extracts at sub-minimum inhibitory concentrations (sub-MICs) significantly enhanced the biofilm formation of P. gingivalis, CLE at sub-MIC did not have any effect on the biofilm formation. The MIC of CLE against P. gingivalis was higher than those against a wide range of other oral bacterial species. P. gingivalis cells were completely killed within 30 min after treatment with CLE. Spatiotemporal analysis using high-speed atomic force microscopy revealed that CLE immediately triggered aberrant membrane vesicle formation on the bacterial surface. Bacterial membrane potential assay revealed that CLE induced depolarization of the bacterial membrane. Taken together, these findings suggest the mechanism behind early bactericidal activity of CLE and its therapeutic applicability in patients with periodontal diseases.

Traditional Medicinal Plants as a Source of Antituberculosis Drugs: A System Review

Medicinal plants are the chief components in the different oriental formulations in different traditional medical systems worldwide. As a thriving source of medicine, the medicinal plants with antituberculosis (TB) properties inspire the pharmacists to develop new drugs based on their active components or semimetabolites. In the present review, the anti-TB medicinal plants were screened from the scientific literatures, based on the botanical classification and the anti-TB activity. The obtained anti-TB medicinal plants were categorized into three different categories, viz., 159 plants critically examined with a total 335 isolated compounds, 131 plants with their crude extracts showing anti-TB activity, and 27 plants in literature with the prescribed formula by the traditional healers. Our systemic analysis on the medicinal plants can assist the discovery of novel and more efficacious anti-TB drugs.

Chemical compositions, antimicrobial effects, and cytotoxicity of Asia minor wormwood (Artemisia splendens Willd.) growing in Iran

BACKGROUND

Artemisia splendens from the Asteraceae family is a new source of biologically active compounds. The current study investigated to evaluate antimicrobial and cytotoxicity activity of methanolic extracts and their fractions obtained from aerial parts by agar disk diffusion and MTT methods, respectively. The active fractions were subjected to preparative HPLC for isolating the pure compounds, which were structurally elucidated, by ¹H and ¹³C NMR.

RESULTS

The results showed that the methanolic extract and its 60% SPE fraction have the anti-proliferative activity on A549 cell line in comparison with the control group. Meanwhile, the methanolic extract and its 40% SPE fraction can inhibit the growth of Gram-positive strains as anti-microbial activity. The 60% SPE fraction also illustrated anti-proliferative activity on the HT-29 cell line compared to the control group. Chromatographic separations via preparative HPLC yielded 5 flavonoids and three flavonoid glycosides.

CONCLUSION

Based on the results it can be concluded that A. splendens as a potential source of cytotoxic and antimicrobial compounds can be used in pharmaceutics.

In vitro antimalarial activity evaluation of two ethnomedicinal plants against chloroquine sensitive and resistant strains of Plasmodium falciparum

Background

In this study, we selected two medicinal plants Citrus maxima (Burm.) Merr. and Artemisia nilagirica (C.B. Clarke) Pamp. on the basis of their traditional use in the treatment of fever associated with malaria in Assam (India) and evaluated their antimalarial potential against Plasmodium falciparum strains.

Methods

The properly processed plant parts of C. maxima (Burm.) Merr. and A. nilagirica (C.B. Clarke) Pamp. were extracted with different solvents from nonpolar to polar by cold maceration technique. After that antimalarial activities of the extracts were evaluated against both chloroquine sensitive (3D7) and resistant (RKL-9) strains of P. falciparum using Giemsa staining light microscopy technique. The most active extract(s) was further screened for cytotoxicity potential against murine macrophage RAW264.7 cell line using MTT assay. Then preliminary phytochemical screening and qualitative fingerprint analysis of the active extract(s) were done to check the presence of different secondary metabolites.

Results

From the in vitro study, the hydro-alcoholic extract of C. maxima (Burm.) Merr. and methanol extract of A. nilagirica (C.B. Clarke) Pamp. were found to be the most active against both 3D7 and RKL-9 strains. In the cytotoxicity study, the CC50 values of the active extracts were found to be > 100 μg/ml, which suggested the safety of the extracts. Then phytochemical and fingerprint analysis revealed the presence of various important plant secondary metabolites in both the extracts.

Conclusion

The findings of this study confirmed the presence of antimalarial potential of hydro-alcoholic extract of C. maxima (Burm.) Merr. and methanol extract of A. nilagirica (C.B. Clarke) Pamp without having any toxic effect. Both the extracts showed IC50 values below 5 μg/ml against 3D7 and RKL-9 strains.

Quality-by-design Enabled Chitosan Nanoparticles for Antitubercular Therapy: Formulation, Statistical Optimization, and In Vitro Characterization

Background:

Tuberculosis (TB) continues to be among the leading causes of high mortality among developing countries. Though a seemingly effective treatment regimen against TB is in place, there has been no significant improvement in the therapeutic rates. This is primarily owing to the high drug doses, their associated side-effects, and prolonged treatment regimen. Discontinuation of therapy due to the severe side effects of the drugs results in the progression of the infection to the more severe drug-resistant TB.

Objectives:

Reformulation of the current existing anti TB drugs into more efficient dosage forms could be an ideal way out. Nanoformulations have been known to mitigate the side effects of toxic, high-dose drugs. Hence, the current research work involves the formulation of Isoniazid (INH; a first-line anti TB molecule) loaded chitosan nanoparticles for pulmonary administration.

Methods:

INH loaded chitosan nanoparticles were prepared by ionic gelation method using an anionic crosslinker. Drug-excipient compatibility was evaluated using DSC and FT-IR. The formulation was optimized on the principles of Quality-by-Design using a full factorial design.

Results:

The obtained nanoparticles were spherical in shape having an average size of 620±10.97 nm and zeta potential +16.87±0.79 mV. Solid-state characterization revealed partial encapsulation and amorphization of INH into the nanoparticulate system. In vitro release study confirmed an extended release of INH from the system. In vitro cell line-based safety and efficacy studies revealed satisfactory results.

Conclusion:

The developed nanosystem is thus an efficient approach for antitubercular therapy.

Phytochemistry and pharmacological activity of the genus artemisia

Artemisia and its allied species have been employed for conventional medicine in the Northern temperate regions of North America, Europe, and Asia for the treatments of digestive problems, morning sickness, irregular menstrual cycle, typhoid, epilepsy, renal problems, bronchitis malaria, etc. The multidisciplinary use of artemisia species has various other health benefits that are related to its traditional and modern pharmaceutical perspectives. The main objective of this review is to evaluate the traditional, modern, biological as well as pharmacological use of the essential oil and herbal extracts of Artemisia nilagirica, Artemisia parviflora, and other allied species of Artemisia. It also discusses the botanical circulation and its phytochemical constituents viz disaccharides, polysaccharides, glycosides, saponins, terpenoids, flavonoids, and carotenoids. The plants have different biological importance like antiparasitic, antimalarial, antihyperlipidemic, antiasthmatic, antiepileptic, antitubercular, antihypertensive, antidiabetic, anxiolytic, antiemetic, antidepressant, anticancer, hepatoprotective, gastroprotective, insecticidal, antiviral activities, and also against COVID-19. Toxicological studies showed that the plants at a low dose and short duration are non or low-toxic. In contrast, a high dose at 3 g/kg and for a longer duration can cause toxicity like rapid respiration, neurotoxicity, reproductive toxicity, etc. However, further in-depth studies are needed to determine the medicinal uses, clinical efficacy and safety are crucial next steps.

Effect of topical administration of propolis in chronic periodontitis

To investigate the effect of topical administration of propolis (a honeybee product) or curry leaf (an herbal product) into the periodontal pockets of periodontitis patients, a double-blind controlled clinical trial was conducted with 24 subjects including one drop-out diagnosed with moderate-to-advanced chronic periodontitis who completed initial periodontal therapy. They were randomly allocated to the following treatments: placebo, propolis, curry leaf, and minocycline. Gingival crevicular fluid (GCF) samples collected before and after the intervention were analyzed to quantify the number of total bacteria and number of six major periodontopathic bacteria by real-time PCR. Periodontitis-related clinical parameters were also analyzed. Among the six propolis-treated patients whose GCF samples were P. gingivalis-positive, three patients converted to be P. gingivalis-negative after the intervention. The minocycline-treated group exhibited a decrease in probing pocket depth (PPD) with statistically significant improvement, but not gain of clinical attachment level (CAL). Both PPD and CAL have been improved in the propolis-treated group at a statistically significant level, but not the curry leaf-treated group. In conclusion, treatment with propolis significantly improved both PPD and CAL, together with a tendency towards reduced P. gingivalis burden in GCF. It is likely that a propolis-based therapy becomes an alternative treatment option for chronic periodontitis during supportive periodontal therapy.

Chitosan derivatives co-delivering nitric oxide and methicillin for the effective therapy to the methicillin-resistant S. aureus infection

We developed a co-delivery system of nitric oxide (NO) and antibiotic for the antibiotic-resistant bacterial infection therapy. The NO could disperse the bacterial biofilms and convert the bacteria into an antibiotic-susceptible planktonic form. Using the chitosan-graft-poly(amidoamine) dendrimer (CS-PAMAM) as the co-delivery system, methicillin (MET) and NO were conjugated successively to form CS-PAMAM-MET/NONOate. The positive CS-PAMAM could efficiently capture the negatively charged bacteria and PAMAM provide abundant reaction points for high payloads of NO and MET. The CS-PAMAM-MET/NONOate displayed effective and combined antibacterial activity to the E. coli and S. aureus. Particularly, for the MET-resistant S. aureus (MRSA), the CS-PAMAM-MET/NONOate displayed the synergistic antibacterial activity. In vivo wound healing assays also confirmed that CS-PAMAM-MET/NONOate could heal the infection formed by MRSA and then accelerate the wound healing effectively. Moreover, CS-PAMAM-MET/NONOate showed no toxicity towards 3T3 cells in vitro and rats in vivo, providing a readily but high-efficient strategy to drug-resistant bacterial infection therapy.

Medicinal Profile, Phytochemistry, and Pharmacological Activities of Murraya koenigii and its Primary Bioactive Compounds

The discovery of several revitalizing molecules that can stop or reduce the pathology of a wide range of diseases will be considered a major breakthrough of the present time. Available synthetic compounds may provoke side effects and health issues, which heightens the need for molecules from plants and other natural resources under discovery as potential methods of replacing synthetic compounds. In traditional medicinal therapies, several plant extracts and phytochemicals have been reported to impart remedial effects as better alternatives. Murraya koenigii (M. koenigii) belongs to the Rutaceae family, which is commonly used as a medicinally important herb of Indian origin in the Ayurvedic system of medicine. Previous reports have demonstrated that the leaves, roots, and bark of this plant are rich sources of carbazole alkaloids, which produce potent biological activities and pharmacological effects. These include antioxidant, antidiabetic, anti-inflammatory, antitumor, and neuroprotective activities. The present review provides insight into the major components of M. koenigii and their pharmacological activities against different pathological conditions. The review also emphasizes the need for more research on the molecular basis of such activity in various cellular and animal models to validate the efficacy of M. koenigii and its derivatives as potent therapeutic agents.

Free radical stress induces DNA damage response in RAW264.7 macrophages during Mycobacterium smegmatis infection

Genomic instability resulting from oxidative stress responses may be traced to chromosomal aberration. Oxidative stress suggests an imbalance between the systemic manifestation of reactive free radicals and biological system's ability to repair resulting DNA damage and chromosomal aberration. Bacterial infection associated insult is considered as one of the major factors leading to such stress conditions. To study free radical responses by host cells, RAW 264.7 macrophages were infected with non-pathogenic M. smegmatis mc²155 at different time points. The infection process was followed up with an assessment of free radical stress, cytokine, toll-like receptors (TLRs) and the resulting DNA damage profiles. Results of CFU count showed that maximum infection in macrophages was achieved after 9 h of infection. Host responses to the infection across different time periods were validated from nitric oxide quantification and expression of iNOS and were plotted at regular intervals. IL-10 and TNF-α expression profile at protein and mRNA level showed a heightened pro-inflammatory response by host macrophages to combat M. smegmatis infection. The expression of TLR4, a receptor for recognition of mycobacteria, in infected macrophages reached the highest level at 9 h of infection. Furthermore, comet tail length, micronuclei and γ-H2AX foci recorded the highest level at 9 h of infection, pointing to the fact that breakage in DNA double strands in macrophage reaches its peak at 9 h of infection. In contrast, treatment with ROS inhibitor N-acetyl-L-cysteine (NAC) prevented host cell death through reduction in oxidative stress and DNA damage response during M. smegmatis infection. Therefore, it can be concluded that enhanced oxidative stress response in M. smegmatis infected macrophages might be correlated with DNA damage response.

Evaluation of antimycobacterial activity of Curcuma xanthorrhiza ethanolic extract against Mycobacterium tuberculosis H37Rv in vitro

Aim:

The aim of this study was to evaluate the antimycobacterial activity of the Curcuma xanthorrhiza ethanolic extract in vitro.

Materials and Methods:

Ethanolic extract of C. xanthorrhiza was set by maceration method. The broth microdilution and disc diffusion method were used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), respectively, of C. xanthorrhiza ethanol extract on strain Mycobacterium tuberculosis H37Rv.

Results:

C. xanthorrhiza ethanol extract was found to have the antimycobacterial effects with a MIC value of 1600 μg/ml while MBC value of 3200 μg/ml for M. tuberculosis H37Rv.

Conclusion:

From these findings , it can be concluded that C. xanthorrhiza ethanol extract have an antibacterial activity against Mycobacterium tuberculosis H37Rv in vitro and its potency elevated by increasing the C. xanthorrhiza ethanol extract concentration.

Development of botanicals to combat antibiotic resistance

The discovery of antibiotics in the previous century lead to reduction in mortality and morbidity due to infectious diseases but their inappropriate and irrational use has resulted in emergence of resistant microbial populations. Alteration of target sites, active efflux of drugs and enzymatic degradations are the strategies employed by the pathogenic bacteria to develop intrinsic resistance to antibiotics. This has led to an increased interest in medicinal plants since 25-50% of current pharmaceuticals are plant derived. Crude extracts of medicinal plants could serve as an alternate source of resistance modifying agents owing to the wide variety of secondary metabolites. These metabolites (alkaloids, tannins, polyphenols etc.) could act as potentials for antimicrobials and resistance modifiers. Plant extracts have the ability to bind to protein domains leading to modification or inhibition protein-protein interactions. This enables the herbals to also present themselves as effective modulators of host related cellular processes viz immune response, mitosis, apoptosis and signal transduction. Thus they may exert their activity not only by killing the microorganism but by affecting key events in the pathogenic process, thereby, the bacteria, fungi and viruses may have a reduced ability to develop resistance to botanicals. The article is meant to stimulate research wherein the cidal activity of the extract is not the only parameter considered but other mechanism of action by which plants can combat drug resistant microbes are investigated. The present article emphasizes on mechanisms involved in countering multi drug resistance.

Allium sativum Constituents Exhibit Anti-tubercular Activity In vitro and in RAW 264.7 Mouse Macrophage Cells Infected with Mycobacterium tuberculosis H37Rv

Background:

Long duration of treatment, side-effects of currently used anti-tubercular drugs and emergence of drug-resistant forms of Mycobacterium tuberculosis (MTB) warrants the need to develop new drugs to tackle the scourge of tuberculosis (TB). Garlic is an edible plant reported to have anti-tubercular activity. However, previous researches on anti-tubercular effect of garlic were focused mostly on preliminary in vitro screening.

Objective:

To identify constituents responsible for anti-tubercular activity of thiosulfinate-derivative rich extract of garlic (GE) and to evaluate activity of the most active constituent in RAW 264.7 mouse macrophage cells infected with M. tuberculosis H37Rv (MTBH).

Materials and Methods:

In the present study, we have isolated eight compounds from GE by flash chromatography. The isolated compounds were characterized by ¹H nuclear magnetic resonance spectroscopy, liquid chromatography-mass spectrometry and Fourier transform infrared spectroscopy. Individual isolates and GE were screened for activity against MTBH by Resazurin Microtitre Plate Assay (REMA).

Results:

Anti-tubercular activity of GE was superior to that of isolates when evaluated by REMA, possibly due to synergism amongst the constituents of GE. Cytotoxicity of GE was evaluated in RAW 264.7 mouse macrophage cells and it was observed that GE had a favorable selectivity index (>10). Therefore, anti-tubercular activity of GE was further evaluated by intracellular macrophage infection model. GE demonstrated concentration-dependent activity in macrophages infected with MTBH.

Conclusion:

This is the first report on intracellular anti-tubercular activity of any extract of garlic or its components. Appreciable intracellular anti-tubercular activity of GE in macrophages combined with low cytotoxicity makes it a suitable candidate for further development as an anti-tubercular agent.

SUMMARY

Thiosulfinate-derivative rich extract of Allium sativum showed better activity than its isolated constituents against Mycobacterium tuberculosis H37Rv.(MTBH) when evaluated by Resazurin Microtitre Plate Assay

The extract showed least cytotoxic potential against RAW 264.7 mouse macrophage cells as compared to rifampicin, isoniazid and ethambutol when evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The extract had an appreciable selectivity index

Extract showed appreciable activity in RAW 264.7 mouse macrophage cells infected with MTBH, indicating its potential to be developed further as an anti-tubercular agent that can be administered as an adjunct to the existing anti-tubercular drug regimen.

Abbreviations used: TB: Tuberculosis, MTB: Mycobacterium tuberculosis, MTBH: Mycobacterium tuberculosis H37Rv, GE: Thiosulfinate-derivative rich extract of garlic, REMA: Resazurin Microtitre Plate Assay, VD: Vinyldithiin, CFU: Colony forming unit, ¹H NMR: ¹H nuclear magnetic resonance spectroscopy, FT-IR: Fourier transform-infrared spectroscopy, LC-MS: Liquid chromatography-mass spectrometry, IC₅₀: Concentration required to inhibit the cells by 50%, ANOVA: Analysis of variance.

Efficient in vitro propagation of Artemisia nilagirica var. nilagirica (Indian wormwood) and assessment of genetic fidelity of micropropagated plants

A reliable protocol has been established for in vitro propagation of Artemisia nilagirica var. nilagirica (Indian wormwood), a valuable medicinal plant from India. A highly proliferating organogenic callus was obtained on Murashige and Skoog (MS) medium supplemented with 2.5 µM IAA when nodal explants were cultured on MS medium supplemented with various growth regulators. Further, highest regeneration frequency (83.3 %) of adventitious shoots was observed, when the callus was sub-cultured on MS medium supplemented with 6-benzylaminopurine (BAP; 2.5 µM) along with 7.5 µM 2-isopentenyl adenine (2-iP). An optimal of 10.16 ± 2.24 shoots were regenerated on medium supplemented with 2.5 µM BAP + 7.5 µM 2-iP. Quarter strength MS medium supplemented with 10 µM IBA was effective for rooting of the shoots. Ex-vitro plants were normal and were established successfully. Cytological and molecular marker studies showed that regenerated plants showed genetic stability in micro-propagated plants.

Phytogenic silver, gold, and bimetallic nanoparticles as novel antitubercular agents

Purpose

Multi- and extensively drug-resistant tuberculosis (TB) is a global threat to human health. It requires immediate action to seek new antitubercular compounds and devise alternate strategies. Nanomaterials, in the present scenario, have opened new avenues in medicine, diagnosis, and therapeutics. In view of this, the current study aims to determine the efficacy of phytogenic metal nanoparticles to inhibit mycobacteria.

Methods

Silver (AgNPs), gold (AuNPs), and gold–silver bimetallic (Au–AgNPs) nanoparticles synthesized from medicinal plants, such as Barleria prionitis, Plumbago zeylanica, and Syzygium cumini, were tested against Mycobacterium tuberculosis and M. bovis BCG. In vitro and ex vivo macrophage infection model assays were designed to determine minimum inhibitory concentration (MIC) and half maximal inhibitory concentration of nanoparticles. Microscopic analyses were carried out to demonstrate intracellular uptake of nanoparticles in macrophages. Besides this, biocompatibility, specificity, and selectivity of nanoparticles were also established with respect to human cell lines.

Results

Au–AgNPs exhibited highest antitubercular activity, with MIC of <2.56 μg/mL, followed by AgNPs. AuNPs did not show such activity at concentrations of up to 100 μg/mL. In vitro and ex vivo macrophage infection model assays revealed the inhibition of both active and dormant stage mycobacteria on exposure to Au–AgNPs. These nanoparticles were capable of entering macrophage cells and exhibited up to 45% cytotoxicity at 30 μg/mL (ten times MIC concentration) after 48 hours. Among these, Au–AgNPs synthesized from S. cumini were found to be more specific toward mycobacteria, with their selectivity index in the range of 94–108.

Conclusion

This is the first study to report the antimycobacterial activity of AuNPs, AgNPs, and Au–AgNPs synthesized from medicinal plants. Among these, Au–AgNPs from S. cumini showed profound efficiency, specificity, and selectivity to kill mycobacteria. These should be investigated further to develop novel TB nanoantibiotics.

Design and Synthesis of 1-((1,5-Bis(4-chlorophenyl)-2-methyl-1H-pyrrol-3-yl)methyl)-4-methylpiperazine (BM212) and N-Adamantan-2-yl-N'-((E)-3,7-dimethylocta-2,6-dienyl)ethane-1,2-diamine (SQ109) Pyrrole Hybrid Derivatives: Discovery of Potent Antitubercular Agents Effective against Multidrug-Resistant Mycobacteria

Novel pyrroles have been designed, synthesized, and evaluated against mycobacterial strains. The pyrroles have originally been designed as hybrids of the antitubercular drugs BM212 (1) and SQ109 (2), which showed common chemical features with very similar topological distribution. A perfect superposition of the structures of 1 and 2 revealed by computational studies suggested the introduction of bulky substituents at the terminal portion of the pyrrole C3 side chain and the removal of the C5 aryl moiety. Five compounds showed high activity toward Mycobacterium tuberculosis, while 9b and 9c were highly active also against multidrug-resistant clinical isolates. Compound 9c showed low eukaryotic cell toxicity, turning out to be an excellent lead candidate for preclinical trials. In addition, four compounds showed potent inhibition (comparable to that of verapamil) toward the whole-cell drug efflux pump activity of mycobacteria, thus turning out to be promising multidrug-resistance-reversing agents.

Mycobacterium tuberculosis effectors interfering host apoptosis signaling

Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

Chemopreventive and immunomodulatory effects of Murraya koenigii aqueous extract on 4T1 breast cancer cell-challenged mice

BACKGROUND

The progression of breast cancer is increasing at an alarming rate, particularly in western countries. Meanwhile, the lower incidence in Asian countries could be attributed to the heavy incorporation of green leaves vegetables or spices in their diets. Murraya koenigii (MK) or often times known as curry leaves are common spice used mostly in tropical countries. Anti-inflammatory and chemopreventive effects of MK aqueous extract on 4T1 breast cancer cell-challenged mice were evaluated.

METHODS

Herein, cytotoxic activity of MK was first tested on 4T1 cells in vitroby MTT assay. Then, in vivo chemopreventive study was conducted where mice were fed with extracts prior to and after inducing the tumor (inoculation). Tumor size was monitored post-4T1 inoculation. At the end of experiment, histopathology of tumor sections, T cell immunophenotyping, tumor nitric oxide level, serum cytokine level and qPCR analysis on expression of iNOS, iCAM, NF-kB and c-MYC were performed.

RESULTS

MK reduced the tumors' size and lung metastasis aside from inhibited the viability of 4T1 cells in vitro. Furthermore, it decreased the level of nitric oxide and inflammation-related cytokines and genes, including iNOS, iCAM, NF-kB and c-MYC.

CONCLUSION

The results propose that, MK managed to inhibit the progression of tumor via immunostimulatory effect and inflammatory reaction within the tumor samples. This suggests that MKconsumption could be a savior in the search of new chemopreventive agents.

Optimization of ultrasound-assisted extraction of flavonoid compounds and their pharmaceutical activity from curry leaf (Murraya koenigii L.) using response surface methodology

Background

Extraction prior to component analysis is the primary step in the recovery and isolation of bioactive phytochemicals from plant materials.

Methods

Response surface methodology was applied to optimize ultrasound-assisted extraction conditions followed by ultra high performance liquid chromatography (UHPLC) to achieve high catechin, myricetin, and quercetin contents, and high antioxidant and anticancer activities in the curry leaf extracts. The antioxidant and anticancer activities of the leaf extracts were determined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, respectively. The central composite experimental design (3-level, 3-factorial) was employed to consider the effects of ultrasonic power (80–150 W), temperature (40–80°C), and methanol dilution (40–80%) on the properties of the curry leaf extracts.

Results

It was found that ultrasonic power of 145.49 W at 55.9°C with 80% methanol was the most appropriate set of conditions for the extraction of catechin, myricetin, and quercetin from curry leaves with the consequent high antioxidant activity. Using the optimum extraction conditions, the extraction yields of catechin, myricetin, and quercetin were 0.482, 0.517, and 0.394 mg/g DW, respectively, and the antioxidant activity was enhanced to 83%. The optimized extract showed more distinct anticancer activity against HeLa cancer cells in a concentration of 67.2 μg/mL (P < 0.01) without toxicity to normal cells.

Conclusions

The results indicated that the pharmaceutical quality of curry leaves could be improved significantly by optimizing the extraction process using response surface methodology.