Oviposition inhibitory activity of the Mexican sunflower Tithonia diversifolia (Asteraceae) polar extracts against the two-spotted spider mite Tetranychus urticae (Tetranychidae)

The Mexican sunflower (Tithonia diversifolia, Asteraceae) is an invasive shrub of agricultural and non-agricultural lands in tropical countries. Besides extensive utilizations in the traditional medicine, mainly to treat malaria, the plant is believed to have a great potential in agriculture of developing countries as a green biomass to produce fertilizer, fodder and biopesticides. The plant is known to produce tagitinins, which are sesquiterpene lactones with a bitter taste endowed with toxicity against several insects such as mosquitoes, aphids, and beetles. Here, we evaluated the potential of T. diversifolia against the two-spotted spider mite Tetranychus urticae (Tetranychidae), which is one of the most economically important arthropod pests worldwide. The leaf methanolic extract and its ethyl acetate fraction were tested for acute and chronic toxicity and for oviposition inhibitory effects. The chemical composition of the extracts was analyzed by HPLC-MSn and NMR. The main constituents were flavonoid derivatives, phenylpropanoids and sesquiterpene lactones. Among the latter, tagitinin C and tagitinin A were the major compounds. In acute toxicity assays, mortality did not exceed 50% even for the highest tested dose of 150 \u3bcg cm-3. However, in chronic toxicity assays, on day 5 from application, the methanolic extract LD50 was 41.3 \u3bcg cm-3 while LD90 was 98.7 \u3bcg cm-3. Furthermore, both T. diversifolia extracts inhibited oviposition in T. urticae. The ethyl acetate extract was the most active oviposition inhibitor, with an ED50 value of 44.3 \u3bcg cm-3 and an ED90 of 121.5 \u3bcg cm-3. Overall, the good yield rate of the extract and the high crop yield highlighted good prospects of using the extract from this plant for the development of oviposition inhibitors against mite

Identification of tagitinin C from Tithonia diversifolia as antitrypanosomal compound using bioactivity-guided fractionation

Tithonia diversifolia (Asteraceae), is used as traditional medicine in tropical countries for the treatment of various diseases, including malaria. Although numerous studies have assessed the antimalarial properties, nothing is known about the effect of T. diversifolia extracts on trypanosomiasis. In this study extracts of T. diversifolia aerial parts were evaluated for their bioactivity against Trypanosoma brucei. The activity was studied against bloodstream forms of T. brucei (TC221), as well as against mammalian cells (BALB/3T3 mouse fibroblasts), as a counter-screen for toxicity. Both methanolic and aqueous extracts showed significant effects with IC50 values of 1.1 and 2.2\u3bcg/mL against T. brucei (TC221) and 5.2 and 3.7\u3bcg/mL against BALB/3T3 cells, respectively. A bioassay-guided fractionation on the methanolic extract yielded in identification of active fractions (F8 and F9) with IC50 values of 0.41 and 0.43\u3bcg/mL, respectively, against T. brucei (TC221) and 1.4 and 1.5\u3bcg/mL, respectively, against BALB/3T3 cells,. The phytochemical composition of the extracts and the purified fractions were investigated using HPLC-ESI-MS/MS and 1D and 2D NMR spectra showing the presence of sesquiterpene lactones that in turn were subjected to the isolation procedure. Tagitinin A and C were rather active but the latter presented a very strong inhibition on T. brucei (TC221) with an IC50 value of 0.0042\u3bcg/mL. This activity was 4.5 times better than that of the reference drug suramin. The results of this study shed light on the antitrypanosomal effects of T. diversifolia extracts and highlighted tagitinin C as one of the possible responsible for this effect. Further structure activity relationships studies on tagitinins are needed to consider this sesquiterpenes as lead compounds for the development of new antitrypanosomal drugs

Phenolic constituents of Erigeron floribundus (Asteraceae), a Cameroonian medicinal plant

HPLC-MS analysis of extracts of the Cameroonian medicinal plant Erigeron floribundus (Kunth) Sch. Bip. (Asteraceae) led to the identification of 40 different phenolic constituents. Four triterpene derivatives were isolated using semi-preparative HPLC and structures were elucidated on the basis of 1D and 2D NMR measurements. Compound 1, olean-3-oleil-12,18 diene, was a new natural product. Quali-quantitative measurements on the infusion obtained from dried aerial parts were also performed by HPLC-MSn and HPLC-DAD analysis showing that a cup of E. floribundus tea contains about 2.7 mg/mL of phenolics, with the caffeoyl quinic derivatives being the most abundant constituents

Identification of Tagitinin C from Tithonia diversifolia as antitrypanosomal compound using bioactivity-guided fractionation

Tithonia diversifolia (Asteraceae), is used as traditional medicine in tropical countries for the treatment of various diseases, including malaria. Although numerous studies have assessed the antimalarial properties, nothing is known about the effect of T. diversifolia extracts on trypanosomiasis. In this study extracts of T. diversifolia aerial parts were evaluated for their bioactivity against Trypanosoma brucei. The activity was studied against bloodstream forms of T. brucei (TC221), as well as against mammalian cells (BALB/3T3 mouse fibroblasts), as a counter-screen for toxicity. Both methanolic and aqueous extracts showed significant effects with IC50 values of 1.1 and 2.2 μg/mL against T. brucei (TC221) and 5.2 and 3.7 μg/mL against BALB/3T3 cells, respectively. A bioassay-guided fractionation on the methanolic extract yielded in identification of active fractions (F8 and F9) with IC50 values of 0.41 and 0.43 μg/mL, respectively, against T. brucei (TC221) and 1.4 and 1.5 μg/mL, respectively, against BALB/3T3 cells,. The phytochemical composition of the extracts and the purified fractions were investigated using HPLC-ESI-MS/MS and 1D and 2D NMR spectra showing the presence of sesquiterpene lactones that in turn were subjected to the isolation procedure. Tagitinin A and C were rather active but the latter presented a very strong inhibition on T. brucei (TC221) with an IC50 value of 0.0042 μg/mL. This activity was 4.5 times better than that of the reference drug suramin. The results of this study shed light on the antitrypanosomal effects of T. diversifolia extracts and highlighted tagitinin C as one of the possible responsible for this effect. Further structure activity relationships studies on tagitinins are needed to consider this sesquiterpenes as lead compounds for the development of new antitrypanosomal drugs

Biological Activities of the Essential Oil from Erigeron floribundus

Erigeron floribundus (Asteraceae) is an herbaceous plant widely used in Cameroonian traditional medicine to treat various diseases of microbial and non-microbial origin. In the present study, we evaluated the in vitro biological activities displayed by the essential oil obtained from the aerial parts of E. floribundus, namely the antioxidant, antimicrobial and antiproliferative activities. Moreover, we investigated the inhibitory effects of E. floribundus essential oil on nicotinate mononucleotide adenylyltransferase (NadD), a promising new target for developing novel antibiotics, and Trypanosoma brucei, the protozoan parasite responsible for Human African trypanosomiasis. The essential oil composition was dominated by spathulenol (12.2%), caryophyllene oxide (12.4%) and limonene (8.8%). The E. floribundus oil showed a good activity against Staphylococcus aureus (inhibition zone diameter, IZD of 14 mm, minimum inhibitory concentration, MIC of 512 µg/mL). Interestingly, it inhibited the NadD enzyme from S. aureus (IC50 of 98 µg/mL), with no effects on mammalian orthologue enzymes. In addition, T. brucei proliferation was inhibited with IC50 values of 33.5 µg/mL with the essential oil and 5.6 µg/mL with the active component limonene. The essential oil exhibited strong cytotoxicity on HCT 116 colon carcinoma cells with an IC50 value of 14.89 µg/mL, and remarkable ferric reducing antioxidant power (tocopherol-equivalent antioxidant capacity, TEAC = 411.9 μmol·TE/g)

Oviposition inhibitory activity of the Mexican sunflower Tithonia diversifolia (Asteraceae) polar extracts against the two-spotted spider mite Tetranychus urticae (Tetranychidae)

The Mexican sunflower (Tithonia diversifolia, Asteraceae) is an invasive shrub of agricultural and non-agricultural lands in tropical countries. Besides extensive utilizations in the traditional medicine, mainly to treat malaria, the plant is believed to have a great potential in agriculture of developing countries as a green biomass to produce fertilizer, fodder and biopesticides. The plant is known to produce tagitinins, which are sesquiterpene lactones with a bitter taste endowed with toxicity against several insects such as mosquitoes, aphids, and beetles. Here, we evaluated the potential of T. diversifolia against the two-spotted spider mite Tetranychus urticae (Tetranychidae), which is one of the most economically important arthropod pests worldwide. The leaf methanolic extract and its ethyl acetate fraction were tested for acute and chronic toxicity and for oviposition inhibitory effects. The chemical composition of the extracts was analyzed by HPLC-MSn and NMR. The main constituents were flavonoid derivatives, phenylpropanoids and sesquiterpene lactones. Among the latter, tagitinin C and tagitinin A were the major compounds. In acute toxicity assays, mortality did not exceed 50% even for the highest tested dose of 150 μg cm-3. However, in chronic toxicity assays, on day 5 from application, the methanolic extract LD50 was 41.3 μg cm-3 while LD90 was 98.7 μg cm-3. Furthermore, both T. diversifolia extracts inhibited oviposition in T. urticae. The ethyl acetate extract was the most active oviposition inhibitor, with an ED50 value of 44.3 μg cm-3 and an ED90 of 121.5 μg cm-3. Overall, the good yield rate of the extract and the high crop yield highlighted good prospects of using the extract from this plant for the development of oviposition inhibitors against mites

Diverse biological effects of the essential oil from Iranian Trachyspermum ammi

Trachyspermum ammi (Apiaceae) is a plant with a good reputation in the traditional Persian and Ayurvedic medicine. The hydrodistilled essential oil from the fruits of T. ammi, known as ‘ajwain oil’, is used in countries such as Iraq, Iran, Afghanistan, Pakistan, and India in the preparation of curry, to flavour several foods, as preservative, and in perfumery. At therapeutic level, ajwain oil is employed in the treatment of gastrointestinal ailments, lack of appetite and bronchial problems. In the present work, the essential oil of T. ammi growing in Iran was analysed by GC–FID and GC–MS showing thymol (67.4%), p-cymene (17.9%) and γ-terpinene (11.3%) as the major constituents. Afterwards, we investigated the biological effects displayed by ajwain oil, namely the antimicrobial and antioxidant activity, the cytotoxicity on tumour cells, and the induction of lymphocyte proliferation. In addition, the inhibition on nicotinate mononucleotide adenylyltransferase (NadD), which is a promising new target for developing novel antibiotics, was evaluated. The antimicrobial effects of ajwain oil, measured by the agar disc diffusion method, were relevant, with inhibition zones higher than those of reference antibiotics, especially on Staphylococcus aureus and Candida albicans (34.7 and 54.3 mm, respectively). This effect was not due to the enzymatic inhibition on NadD. The ajwain oil exhibited a considerable dose-dependent inhibition on the ABTS radical cation, with an IC50 value of 22.4 μg/mL. MTT assay revealed that ajwain oil is particularly cytotoxic on colon carcinoma cells, with a IC50 value of 9.6 μg/mL. Finally, PBMC proliferation assay revealed some role for the ajwain oil within the network of interactions of the cells of the immune system

Trypanosoma brucei Inhibition by Essential Oils from Medicinal and Aromatic Plants Traditionally Used in Cameroon (Azadirachta indica, Aframomum melegueta, Aframomum daniellii, Clausena anisata, Dichrostachys cinerea and Echinops giganteus)

Essential oils are complex mixtures of volatile components produced by the plant secondary metabolism and consist mainly of monoterpenes and sesquiterpenes and, to a minor extent, of aromatic and aliphatic compounds. They are exploited in several fields such as perfumery, food, pharmaceutics, and cosmetics. Essential oils have long-standing uses in the treatment of infectious diseases and parasitosis in humans and animals. In this regard, their therapeutic potential against human African trypanosomiasis (HAT) has not been fully explored. In the present work, we have selected six medicinal and aromatic plants (Azadirachta indica, Aframomum melegueta, Aframomum daniellii, Clausena anisata, Dichrostachys cinerea, and Echinops giganteus) traditionally used in Cameroon to treat several disorders, including infections and parasitic diseases, and evaluated the activity of their essential oils against Trypanosma brucei TC221. Their selectivity was also determined with Balb/3T3 (mouse embryonic fibroblast cell line) cells as a reference. The results showed that the essential oils from A. indica, A. daniellii, and E. giganteus were the most active ones, with half maximal inhibitory concentration (IC50) values of 15.21, 7.65, and 10.50 mu g/mL, respectively. These essential oils were characterized by different chemical compounds such as sesquiterpene hydrocarbons, monoterpene hydrocarbons, and oxygenated sesquiterpenes. Some of their main components were assayed as well on T. brucei TC221, and their effects were linked to those of essential oils