Antibacterial Activity of Essential Oils Combinations based on Thymus broussonnetii, and Their Synergism with some Antibiotics.

The present study aimed to evaluate the antibacterial activity of the essential oil (EO) of Moroccan endemic Thymus broussonnetii alone, and in combination with EOs obtained from selected medicinal plants, namely Myrtus communis, Artemisia herba alba, Thymus pallidus, Thymus satureioides, Teucrium polium, and Rosmarinus officinalis. The synergistic interactions between the most effective combinations based on T. broussonnetii EO with two conventional antibiotics (streptomycin and ciprofloxacin) were also investigated. T. broussonnetii EO possessed a higher inhibitory activity against tested pathogenic bacteria with inhibition zone diameter (IZ) ranging from 21.61 ± 0.03 to 40.09 ± 0.02 mm, and MIC values between 0.140 mg/mL and 0.280 mg/mL. M. communis, A. herba alba, T. pallidus, T. satureioides, T. polium, and R. officinalis EOs showed moderate to weak antibacterial activity. Among tested EO mixtures, the highest synergistic antibacterial effect was recorded with the EO combination of T. broussonnetii and T. pallidus against S. aureus, E. coli, and S. enterica (FICI = 0.258). This EO combination was also the most effective mixture to synergistically enhance the antibacterial activity of the two antibiotics with up to a 128-fold increase, particularly against the gram-negative E. coli. These findings suggest that T. broussonnetii EO may be an interesting source of natural antimicrobials, for use in combination therapies with other plant EOs, and with conventional antimicrobial drugs to tackle the emergence of multidrug-resistant bacteria.

Plant-food-derived Bioactives in Managing Hypertension: From Current Findings to Upcoming Effective Pharmacotherapies.

A sedentary lifestyle has evoked a high risk of cardiovascular (CV) disease, diabetes, and obesity, all of them with high morbimortality rates and with a common denominator, hypertension. Numerous pharmacological drugs have been used for the treatment of hypertension. However, the side effects associated with the use of existing pharmacological therapies have triggered a demand for plant-based medications. In this connection, the aim of this review was to provide an in-depth analysis of the use of plant-derived bioactives for the effective management of hypertension. Phytoconstituents from leaves, bark, stem, roots, seeds, and fruits of medicinal plants grown in our different regions of the globe have been highly searched. Among them, polyphenols (e.g., flavonoids as quercetin, anthocyanins as cyanidin, tannins as ellagic acid, stilbenes as resveratrol, lignans as honokiol and others as hydroxytyrosol or curcumin), organosulfur compounds (e.g. s-allyl cysteine and allicin), fatty acids (e.g. α-lipoic acid, DHA and oleic acid), alkaloids (e.g. berberine or tetrandrine) and some terpenes have been intensively investigated for the management of hypertension, with effective ability being stated in controlling high blood pressure and related health problems both in vivo and in vitro studies. Some of the activities presented by these bioactive compounds are reducing oxidative stress, renin-angiotensin system control, SIRT1 activation, regulating platelet aggregation and COX activity, anti-atherogenic effects, anti-inflammatory properties, vasorelaxation and other results that translate into the prevention or control of hypertension. The knowledge of these bioactive compounds is important in developing countries where traditional medicine is the majority, but it can also give rise to new approaches in hypertension therapy.

Chemical characterization by GC/MS analysis of Lactuca tatarica (L.) C.A.Mey. aerial parts and seeds.

Lactuca tatarica is a wild species belonging to Asteraceae family omnipresent in Southern Caucasus region including Azerbaijan. Previous studies on the chemical content of some extracts obtained from its different organs have reported the presence of lactone sesquiterpenes, triterpenoids and flavonoids. For the first time, we investigated the volatile composition of L. tatarica aerial parts and seeds by GC/MS technique. The results showed the predominant presence of fatty acids, both saturated and unsaturated. Palmitic acid was prevalent in the aerial parts (up to 89.9%) while linoleic acid (up to 82.6%) was the most abundant component in the seeds. Other minor components were terpene and hydrocarbon derivatives. Some of the detected constituents in L. tatarica have already demonstrated antibacterial, antifungal, anti-inflammatory and antioxidant activity. Therefore, this species could be better studied for its biological properties and considered as a source of active ingredients useful in various fields including the pharmaceutical one.

Santalum Genus: phytochemical constituents, biological activities and health promoting-effects.

Santalum genus belongs to the family of Santalaceae, widespread in India, Australia, Hawaii, Sri Lanka, and Indonesia, and valued as traditional medicine, rituals and modern bioactivities. Sandalwood is reported to possess a plethora of bioactive compounds such as essential oil and its components (α-santalol and ß-santalol), phenolic compounds and fatty acids. These bioactives play important role in contributing towards biological activities and health-promoting effects in humans. Pre-clinical and clinical studies have shown the role of sandalwood extract as antioxidant, anti-inflammatory, antibacterial, antifungal, antiviral, neuroleptic, antihyperglycemic, antihyperlipidemic, and anticancer activities. Safety studies on sandalwood essential oil (EO) and its extracts have proven them as a safe ingredient to be utilized in health promotion. Phytoconstituents, bioactivities and traditional uses established sandalwood as one of the innovative materials for application in the pharma, food, and biomedical industry.

Natural essential oils as a new therapeutic tool in colorectal cancer.

Colorectal cancer (CRC) is the third most revalent type of cancer in the world and the second most common cause of cancer death (about 1 million per year). Historically, natural compounds and their structural analogues have contributed to the development of new drugs useful in the treatment of various diseases, including cancer. Essential oils are natural odorous products made up of a complex mixture of low molecular weight compounds with recognized biological and pharmacological properties investigated also for the prevention and treatment of cancer. The aim of this paper is to highlight the possible role of essential oils in CRC, their composition and the preclinical studies involving them. It has been reviewed the preclinical pharmacological studies to determine the experimental models used and the anticancer potential mechanisms of action of natural essential oils in CRC. Searches were performed in the following databases PubMed/Medline, Web of science, TRIP database, Scopus, Google Scholar using appropriate MeSH terms. The results of analyzed studies showed that EOs exhibited a wide range of bioactive effects like cytotoxicity, antiproliferative, and antimetastatic effects on cancer cells through various mechanisms of action. This updated review provides a better quality of scientific evidence for the efficacy of EOs as chemotherapeutic/chemopreventive agents in CRC. Future translational clinical studies are needed to establish the effective dose in humans as well as the most suitable route of administration for maximum bioavailability and efficacy. Given the positive anticancer results obtained from preclinical pharmacological studies, EOs can be considered efficient complementary therapies in chemotherapy in CRC.

Resveratrol-Mediated Gold-Nanoceria Synthesis as Green Nanomedicine for Phytotherapy of Hepatocellular Carcinoma.

BACKGROUND: In the present study, resveratrol was used to prepare complexes of cerium and nanoceria, also coated with gold (CeO2@Au core-shells) to improve the surface interactions in physiological conditions. METHODS: The CeO2@Au core-shells were characterized using powder X-ray diffraction (PXRD), Fourier transforms infrared spectroscopy (FTIR), transmission electron microscope (TEM) analysis, dynamic light scattering (DLS) and ζ potential. RESULTS: The experiment was led to the successful synthesis of nanosized CeO2@Au core-shells, although agglomeration of particles caused the distribution of the larger particles. The TEM analysis demonstrated the particles sizes ranged from 20 nm to 170 nm. Moreover, the PXRD analysis showed that both nanoceria and gold with the same crystal systems and space groups. To investigate the anticancer activity of the CeO2@Au core-shells, the cytotoxicity of the nanoparticles was investigated against liver cancerous cell lines (HepG2). CONCLUSIONS: The results indicated biosynthesized NCs have significant cellular toxicity properties against HepG2 and could be utilized in hepatocarcinoma therapy. Further in vivo investigations is proposed to be designed to assess anti-cancer and safety effects of fabricated nanocomposites.

Digestive and gastroprotective effects of Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae): From traditional uses to preclinical studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae) is an alpine endemic plant whose aerial parts are harvested by the locals mainly for the digestive properties. Despite its widespread use, few studies have been conducted to date to verify its bioactivity. AIM OF THE STUDY: The purpose of the work was to meet the tradition confirming with experimental data the popular belief that the consumption of this species offers beneficial effects to the gastrointestinal system. MATERIALS AND METHODS: Using Soxhlet apparatus, the dried aerial parts of A. erba-rotta subsp. moschata were successively extracted with petroleum ether (PET), dichloromethane (DCM) and methanol (MeOH). The essential oil (EO) was obtained by hydrodistillation using a Clevenger apparatus while infusion (AE) was prepared following the traditional local recipe. Their chemical characterization was performed by various techniques including SPME-GC/MS, GC/MS and HPLC/MS-MS. An in vitro biological screening was carried out. The influence of AE on lipid digestion was monitored by titration of free fatty acids (FFA) during pancreatic lipase activity with the pH-stat method. For all extracts and EO, the anti-Helicobacter pylori activity was assessed by the broth microdilution method, the influence on cell viability was evaluated against NCI-N87, OE21 and Caco-2 cell lines and a preliminary toxicity evaluation was done using Brine Shrimp lethality (BSL) assay. The anti-inflammatory potential was evidenced by interleukin IL-1- induced IL8 expression on Caco-2 cells. RESULTS: AE increased by 15% the FFA releasing compared to the pancreatic lipase alone. PET, DCM and MeOH extracts as well as AE and EO were considered active against the growth of both antimicrobial susceptible and resistant strains of H. pylori with MIC values starting from 16 µg/mL. PET and DCM (IC50 = 89 µg/mL and 96 µg/mL, respectively, against Caco-2 cell line) extracts showed the high effect on cell viability while the EO reduced in 50% of cell viability at 1.48 µL/mL (NCI-N87 cells), 1.42 µL/mL (OE21 cells), and 3.44 µL/mL (Caco-2 cells) corroborating the BSL results. In different degrees, all extracts and EO inhibited the IL-1ß-stimulated IL-8 production in Caco-2 cells. CONCLUSIONS: The obtained data are encouraging and provide a scientific basis for the traditional use of A. erba-rotta subsp. moschata as a digestive agent although they need to be further corroborated by studies involving the investigation of both the in vivo activities and the role of the compounds detected in the extracts.

Solanum linnaeanum Leaves: Chemical Profiling of VOCs and Effects on Seed Germination and Early Growth of Monocots and Dicots.

Some Solanaceae plants are a rich source of sesquiterpenoid phytoalexins with allelopathic potential. Powder and aqueous extract obtained from the leaves of Solanum linnaeanum Hepper & P.M.L. Jaeger were used to treat the seeds of three target species (Lolium multiflorum Lam., Sinapis alba L. and Trifolium incarnatum L.). Both matrices were evaluated along with untreated controls to determine their toxicity on germination and seedling growth. The results revealed that the pre-emergence treatments were able to be very effective against all three species in the filter paper test by inhibiting the germination up to 100 %. The effectiveness was reduced by the interaction with soil. Despite this, significant data were obtained, albeit different according to the applied matrix. In general, L. multiflorum was the most sensitive to both the action of the leaf powder and aqueous extract while S. alba was found to be the most resistant to powder activity and T. incarnatum had the strongest response to the extract. For the first time, SPME-GC/MS technique was used to characterize the volatile chemical profile of S. linnaeanum leaves. The analyses highlighted the presence of different classes of compounds including terpenoids and sesquiterpenoids potentially useful in the fight against noxious plants both in natural and cultivated ecosystems.

Antidiarrheal and antispasmodic activities of Trillium govanianum rhizomes extract: involvement of calcium channel blockade.

The antidiarrheal effect of methanolic extract of Trillium govanianum Wall. ex D. Don (Melanthiaceae alt. Trilliaceae) was studied at doses of 12.5, 25, and 50 mg/kg in different animal models of diarrhea including castor oil (6 mL/kg), magnesium sulfate (2 gm/kg), sodium picosulfate (2 mL/kg) and lactitol (0.25 mL/kg). The antispasmodic effect of T. govanianum was studied on isolated rabbit's jejunum, using acetylcholine as tissue stabiliser and verapamil as calcium channel blocker. T. govanianum attenuated the diarrhea by producing a significant decrease in the number and weight of stool, and an increase in stool latency time. T. govanianum completely inhibited both spontaneous as well as high potassium induced contractions of isolated rabbit's jejunum, which was analogous to verapamil. Moreover, T. govanianum produced a right shift in calcium concentration response curve, confirming its calcium channel blocking activity. These findings provide scientific ground to its medicinal use in diarrhea and gut spasms.

Antimicrobial Activity and Synergy Investigation of Hypericum scabrum Essential Oil with Antifungal Drugs.

The chemical composition of Lebanese Hypericum scabrum essential oil (EO) was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GG-MS). Its antimicrobial activity was evaluated by determining its minimal inhibitory concentrations (MICs) against a Gram-negative and a Gram-positive bacterium, one yeast, and five dermatophytes. H. scabrum EO was most active on filamentous fungi (MIC values of 32-64 µg/mL). Synergy within the oil was investigated by testing each of the following major components on Trichophyton rubrum: α-pinene, limonene, myrcene, ß-pinene and nonane, as well as a reconstructed EO. The antifungal activity of the natural oil could not be reached, meaning that its activity might be due, in part, to minor constituent(s). The interactions between H. scabrum EO and commercially available antifungals were assessed by the checkerboard test. A synergistic effect was revealed in the combination of the EO with amphotericin B.

Synergistic Anticandidal Effects of Six Essential Oils in Combination with Fluconazole or Amphotericin B against Four Clinically Isolated Candida Strains.

The development of opportunistic pathogenic Candida strains insensitive to several classes of antifungals has emerged as a major health care problem during the last years. Combinational therapy of natural products (e.g., essential oils, EOs) with conventional antifungals has been suggested as a promising alternative to overcome this medical problem. The present study investigates the potential antifungal activity of EOs extracted from some selected medicinal plants, alone and in combination with two common conventional antifungals (fluconazole and amphotericin B) against four clinical Candida isolates. MIC assays indicated that EOs induced strong anticandidal activities with MIC values ranging from 0.162 to 4.950 mg/mL. The combination of amphotericin B with Thymus leptobotrys, Origanum compactum and Artemisia herba alba EOs provided a synergistic effect against C. krusei only, with MIC gain of four-fold, and additive effect against remaining strains (MIC gain = two-fold). Interesting synergistic interactions were observed by combining all studied EOs with fluconazole, with reduction rates of their MICs ranging from 16 to 512-fold. This synergistic effect was very pronounced with the combination of T. leptobotrys EO and fluconazole. These findings indicate that studied EOs can be used as anti-candidals in combination with antifungals, particularly fluconazole, to counteract the emergence of resistant Candida spp.

A Comparative Study of the Chemical Composition by SPME-GC/MS and Antiradical Activity of Less Common Citrus Species.

Citrus secondary metabolites, such as terpene compounds, are very important for human health due to their bioactivity including anti-inflammatory, anti-cancer, and antioxidant effects. In this work, for the first time, the volatile chemical composition of peels and juices from four different Citrus species (C. junos, Citrus × aurantium, C. aurantium 'Bizzarria' and C. medica 'Florentina', commonly known as Yuzu jeune, Oni Yuzu, Bizzarria orange and Florence cedar, respectively) was investigated by Solid-Phase Microextraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS) technique and the antiradical activity was also examined. The results showed that limonene and γ-terpinene were the main volatile substances detected both in the juices and in the peels, followed by other minority compounds responsible for the phyto-complex of the unique aromas which characterize each individual analyzed Citrus species. Principal component analysis (PCA), performed on volatile compounds, showed both some correlation as well as a clear separation between the juice and the peel of each species. Among them, Oni Yuzu juice was found to be the richest in total polyphenols and flavonoids while its capacity to scavenge ABTS•+ and DPPH• radicals was similar to that of Yuzu Jeune and Bizzarria orange.

Analysis of Peganum harmala, Melia azedarach and Morus alba extracts against six lethal human cancer cells and oxidative stress along with chemical characterization through advance Fourier Transform and Nuclear Magnetic Resonance spectroscopic methods towards green chemotherapeutic agents.

Traditional medicines implicate consumption of plant crude extracts, which may consist of extensive phytochemical diversity. Overall, the most biologically active extract of Peganum harmala (seeds) exhibited significant cytotoxic activity on Artemia salina with LC50 value of 61.547 µg/mL, while P. harmala (roots) [LC50 = 124.229 µg/mL] and M. azedarach (fruits) [LC50 = 147.813 µg/mL] showed moderate cytotoxic potential. P. harmala (seeds) extract also showed the maximum antitumor potential with 52.278 µg/mL LC50. Branches of P. harmala and Morus alba were not active in both bioassays. These outcomes were further reinforced by the levels of phenolics and flavonoids checked against gallic acid and quercetin equivalents, respectively, by standard curves. Current study aims to isolate, structurally characterize and analyze the bioactive compound from plant extracts by using chromatographic and spectrophotometric techniques. Bioactivity guided isolation of extracts led to the isolation of PH-HM-16 from ethyl acetate fraction P. harmala seeds. Chemical structure of PH-HM-16 was elucidated by ESI-MS, 1H NMR, 13C NMR, HSQC and IR spectrum. The results demonstrated significant positive anticancer activities against six human cancer cell lines assessed through MTT cancer cell growth inhibition assay. PH-HM-16 was most effective against prostate cancer cell lines [IC50 = 17.63 µg/mL] followed by breast cancer cell line MCF7 [IC50 value of 41.81 µg/mL]. IC50 value of PH-HM-16 against human myeloid leukemia cell line HL-60 and human colorectal tumor cells HCT-116 was observed as 68.77 µg/mL and 71.54 µg/mL respectively. The IC 50 value of PH-HM-16 compound was not significant against human gastric cancer SGC-7901 (111.89 µg/mL) and human lung adenocarcinoma epithelial cell line A549 (176.04 µg/mL). Isolated bioactive metabolite PH-HM-16 possesses significant antitumor potential so this could be the first step to develop an effective anticancer agent. Hence, this compound represents a promising potential to be chemically standardized or developed into pharmaceuticals for the chemoprevention and/or the treatment of certain types of cancer, especially as adjuvant phytotherapeutics in conventional chemotherapy.

Curcumin nanoformulations for antimicrobial and wound healing purposes.

The development and spread of resistance to antimicrobial drugs is hampering the management of microbial infectious and wound healing processes. Curcumin is the most active and effective constituent of Curcuma longa L., also known as turmeric, and has a very long and strong history of medicinal value for human health and skincare. Curcumin has been proposed as strong antimicrobial potentialities and many attempts have been made to determine its ability to conjointly control bacterial growth and promote wound healing. However, low aqueous solubility, poor tissue absorption and short plasma half-life due its rapid metabolism needs to be solved for made curcumin formulations as suitable treatment for wound healing. New curcumin nanoformulations have been designed to solve the low bioavailability problem of curcumin. Thus, in the present review, the therapeutic applications of curcumin nanoformulations for antimicrobial and wound healing purposes is described.

Antioxidant potential of family Cucurbitaceae with special emphasis on Cucurbita genus: A key to alleviate oxidative stress-mediated disorders.

Oxidative stress is the imbalance between reactive oxygen species (ROS) production, and accumulation and the ability of a biological system to clear these reactive products. This imbalance leads to cell and tissue damage causing several disorders in human body, such as neurodegeneration, metabolic problems, cardiovascular diseases, and cancer. Cucurbitaceae family consists of about 100 genera and 1,000 species of plants including mostly tropical, annual or perennial, monoecious, and dioecious herbs. The plants from Cucurbita species are rich sources of phytochemicals and act as a rich source of antioxidants. The most important phytochemicals present in the cucurbits are cucurbitacins, saponins, carotenoids, phytosterols, and polyphenols. These bioactive phyto-constituents are responsible for the pharmacological effects including antioxidant, antitumor, antidiabetic, hepatoprotective, antimicrobial, anti-obesity, diuretic, anti-ulcer activity, and antigenotoxic. A wide number of in vitro and in vivo studies have ascribed these health-promoting effects of Cucurbita genus. Results of clinical trials suggest that Cucurbita provides health benefits for diabetic patients, patients with benign prostate hyperplasia, infertile women, postmenopausal women, and stress urinary incontinence in women. The intend of the present review is to focus on the protective role of Cucurbita spp. phytochemicals on oxidative stress-related disorders on the basis of preclinical and human studies. The review will also give insights on the in vitro and in vivo antioxidant potential of the Cucurbitaceae family as a whole.

Monthly changes in contents and compositions of oil of Callistemon citrinus: a comparison study.

The essential oil components of fresh and dry aerial parts of Callistemon citrinus, monthly harvested from Iran during a year, were compared. The EO contents of dry plant samples were dramatically higher than the fresh materials. The dry sample collected in March with 1.10 ± 0.04% and fresh in August with 0.16 ± 0.01% (w/w), possessed the highest and lowest EO yields, respectively. From thirty-two identified aroma phytoconstituents, 1,8-cineole was the major compound with quantity variation of 60.01% in dry sample collected in January and 33.92% in fresh from August. In summer, the amount of α-pinene as the second predominant volatile terpenoid was raised, while dry sample in August (46.92%) was the richest. The present study explicitly demonstrates the impact of harvesting period on volatile oil contents of C. citrinus and the findings are considerable to obtain the favourite EO compositions for consuming in food and phyto-pharmaceutical industries.

Chemical composition, antitumor and antioxidant effects of four lebanese plants extracts on human pulmonary adenocarcinoma.

Lung cancer leading cause of humans' cancer-related death remains incurable with current drug therapies having many side-effects. Finding new natural cancer remedies would help design better therapies. This study aims to investigate the anticancer and antioxidant effects of the Levant endemic plants Prango sasperula, Stachys ehrenbergii, Hirtellina lobelia, and Salvia multicaulis on human pulmonary adenocarcinoma. GC/MS and NMR analyzed the bioactive compounds of methanolic extracts of these plants. Their antioxidant effect was measured by ABTS assay. The effect of these extracts on the viability of A549 (Human lung adenocarcinoma cell line) and NHBE (Normal Human Bronchial Epithelial Cells) was examined using MTT and Anchorage-Independent Colony Formation assays. Our findings show an interesting, specific cytotoxic effect of these plant extracts on A549 cells. Additionally, S. ehrenbergii and H. lobelii present a specific high alkylation potential. Data reveal an interesting antitumor potential attributed to their antiproliferative and alkylation actions towards human pulmonary adenocarcinoma.

Gas chromatography coupled to mass spectrometry (GC-MS) characterization and evaluation of antibacterial bioactivities of the essential oils from Piper arboreum Aubl., Piper aduncum L. e Piper gaudichaudianum Kunth.

The objective of this study was to determine the chemical profile and to evaluate the antibacterial activity of the essential oils of Piper species and modulation of the antibiotic activity, using the microdilution method to determine the minimum inhibitory concentration. The chemical components were characterized by gas chromatography coupled to mass spectrometry, which revealed ß-copaen-4-α-ol (31.38%), spathulenol (25.92%), and germacrene B (21.53%) as major constituents of the essential oils of Piper arboreum, Piper aduncum, and Piper gaudichaudianum, respectively. The essential oils analyzed in this study did not present a clinically relevant activity against standard and multiresistant Escherichia coli. However, in the case of multiresistant Staphylococcus aureus, there was a significant activity, corroborating with reports in the literature, where Gram-positive bacteria are more susceptible to antimicrobial activity. The essential oils modulated the effect of the antibiotics norfloxacin and gentamicin, having on the latter greater modulating effect; however, for erythromycin, no statistically significant effect was observed. In conclusion, the results obtained in this study demonstrated that the essential oils of the analyzed Piper species present an inhibitory effect against S. aureus and modulate antibiotic activity, most of which presents synergistic activity.

Medicinal plants used in the treatment of tuberculosis - Ethnobotanical and ethnopharmacological approaches.

Tuberculosis is a highly infectious disease declared a global health emergency by the World Health Organization, with approximately one third of the world's population being latently infected with Mycobacterium tuberculosis. Tuberculosis treatment consists in an intensive phase and a continuation phase. Unfortunately, the appearance of multi drug-resistant tuberculosis, mainly due to low adherence to prescribed therapies or inefficient healthcare structures, requires at least 20 months of treatment with second-line, more toxic and less efficient drugs, i.e., capreomycin, kanamycin, amikacin and fluoroquinolones. Therefore, there exists an urgent need for discovery and development of new drugs to reduce the global burden of this disease, including the multi-drug-resistant tuberculosis. To this end, many plant species, as well as marine organisms and fungi have been and continue to be used in various traditional healing systems around the world to treat tuberculosis, thus representing a nearly unlimited source of active ingredients. Besides their antimycobacterial activity, natural products can be useful in adjuvant therapy to improve the efficacy of conventional antimycobacterial therapies, to decrease their adverse effects and to reverse mycobacterial multi-drug resistance due to the genetic plasticity and environmental adaptability of Mycobacterium. However, even if some natural products have still been investigated in preclinical and clinical studies, the validation of their efficacy and safety as antituberculosis agents is far from being reached, and, therefore, according to an evidence-based approach, more high-level randomized clinical trials are urgently needed.