Effect of myrrh and thyme on Trichinella spiralisenteral and parenteral phases with inducible nitric oxide expression in mice

Trichinellosis is a serious disease with no satisfactory treatment. We aimed to assess the effect of myrrh (Commiphora molmol) and, for the first time, thyme (Thymus vulgaris L.) against enteral and encysted (parenteral) phases of Trichinella spiralis in mice compared with albendazole, and detect their effect on inducible nitric oxide synthase (iNOS) expression. Oral administration of 500 mg/kg of myrrh and thyme led to adult reduction (90.9%, 79.4%), while 1,000 mg/kg led to larvae reduction (79.6%, 71.3%), respectively. Administration of 50 mg/kg of albendazole resulted in adult and larvae reduction (94.2%, 90.9%). Positive immunostaining of inflammatory cells infiltrating intestinal mucosa and submucosa of all treated groups was detected. Myrrh-treated mice showed the highest iNOS expression followed by albendazole, then thyme. On the other hand, both myrrh and thyme-treated groups showed stronger iNOS expression of inflammatory cells infiltrating and surrounding encapsulated T. spiralis larvae than albendazole treated group. In conclusion, myrrh and thyme extracts are highly effective against both phases of T. spiralis and showed strong iNOS expressions, especially myrrh which could be a promising alternative drug. This experiment provides a basis for further exploration of this plant by isolation and retesting the active principles of both extracts against different stages of T. spiralis.

Cytotoxic effect of essential oil of thyme (Thymus broussonettii) on the IGR-OV1 tumor cells resistant to chemotherapy

The anti-tumor effect of the Moroccan endemic thyme (Thymus broussonettii) essential oil (EOT) was investigated in vitro using the human ovarian adenocarcinoma IGR-OV1 parental cell line OV1/P and its chemoresistant counterparts OV1/adriamycin (OV1/ADR), OV1/vincristine (OV1/VCR), and OV1/cisplatin (OV1/CDDP). All of these cell lines elicited various degrees of sensitivity to the cytotoxic effect of EOT. The IC50 values (mean ± SEM, v/v) were 0.40 ± 0.02, 0.39 ± 0.02, 0.94 ± 0.05, and 0.65 ± 0.03% for OV1/P, OV1/ADR, OV1/VCR, and OV1/CDDP, respectively. Using the DBA-2/P815 (H2d) mouse model, tumors were developed by subcutaneous grafting of tumor fragments of similar size obtained from P815 (murin mastocytoma cell line) injected in donor mouse. Interestingly, intra-tumoral injection of EOT significantly reduced solid tumor development. Indeed, by the 30th day of repeated EOT treatment, the tumor volumes of the animals were 2.00 ± 0.27, 1.35 ± 0.20, and 0.85 ± 0.18 cm³ after injection with 10, 30, or 50 µL per 72 h (six times), respectively, as opposed to 3.88 ± 0.50 cm³ for the control animals. This tumoricidal effect was associated with a marked decrease of mouse mortality. In fact, in these groups of mice, the recorded mortality by the 30th day of treatment was 30 ± 4, 18 ± 4, and 8 ± 3%, respectively, while the control animals showed 75 ± 10% of mortality. These data indicate that the EOT which contains carvacrol as the major component has an important in vitro cytotoxic activity against tumor cells resistant to chemotherapy as well as a significant antitumor effect in mice. However, our data do not distinguish between carvacrol and the other components of EOT as the active factor.

Antioxidant potential of oregano (Oreganum vulgare L.), basil (Ocimum basilicum L.) and thyme (Thymus vulgaris L.): application of oleoresins in vegetable oil

Studies have been carried out in order to increase the stability of vegetable oils due to economic and health protection reasons. There is a growing interest in the addition of natural antioxidants; especially herbs and spices. For this reason, this study aimed at evaluating the antioxidant potential of the oleoresins of oregano, basil, and thyme, as well as their behavior when applied to soybean oil under various concentrations. Firstly, the antioxidant activity was determined by the β-carotene/linoleic acid system and by the quantification of total phenolic compounds. Next, different concentrations of oleoresins (500 to 3000 mg.kg-1) were added to the soybean oil, and its antioxidant potential was analyzed using the oxidative stability through a Rancimat equipment. The value of 3000 mg.kg-1 of thyme and oregano oleoresins was the concentration that presented the greatest oxidative stability to soybean oil making them a natural alternative to vegetable oil conservation.

Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

The objective of this work was to evaluate the effects of plant essential oils (EOs) on the growth of Xanthomonas vesicatoria, on bacterial morphology and ultrastructure, and on the severity of tomato bacterial spot. EOs from citronella, clove, cinnamon, lemongrass, eucalyptus, thyme, and tea tree were evaluated in vitro at concentrations of 0.1, 1.0, 10, and 100% in 1.0% powdered milk. The effect of EOs, at 0.1%, on the severity of tomato bacterial spot was evaluated in tomato seedlings under greenhouse conditions. The effects of citronella, lemongrass, clove, and tea tree EOs, at 0.1%, on X. vesicatoria cells were evaluated by transmission electron microscopy. All EOs showed direct toxic effect on the bacteria at a 10%-concentration in vitro. Under greenhouse conditions, the EOs of clove, citronella, tea tree, and lemongrass reduced disease severity. EOs of clove and tea tree, and streptomycin sulfate promoted loss of electron-dense material and alterations in the cytoplasm, whereas EO of tea tree promoted cytoplasm vacuolation, and those of citronella, lemongrass, clove, and tea tree caused damage to the bacterial cell wall. The EOs at a concentration of 0.1% reduce the severity of the disease.