The antimicrobial activities of the isomers and enantiomers of pinene were evaluated against bacterial and fungal cells. The agar diffusion test showed that only the positive enantiomers of the a- and β-isomers of pinene were active. The minimal inhibitory concentration (MIC) and minimal microbicidal concentration (MMC) of these monoterpenes were also determined, confirming that the positive enantiomers exhibited microbicidal activity against all fungi and bacteria tested with MICs ranging from 117 to 4,150 µg/mL. However, no antimicrobial activity was detected with the negative enantiomers up to 20 mg/mL. Time-kill curves showed that (+)-a-pinene and (+)-β-pinene were highly toxic to Candida albicans, killing 100% of inoculum within 60 min. By contrast, the bactericidal effect occurred after 6 h in methicillin-resistant Staphylococcus aureus (MRSA). In combination with commercial antimicrobials, ciprofloxacin plus (+)-a-pinene or (+)-β-pinene presented synergistic activity against MRSA whereas an indifferent effect against all fungi was detected when amphotericin B was combined with the positive enantiomers of pinene. The potential of (+)-a-pinene and (+)-β-pinene to inhibit phospholipase and esterase activities was also evaluated, and the best inhibition results were obtained with Cryptococcus neoformans. C. albicans biofilm formation was prevented with the MIC concentration of (+)-a-pinene and twice the MIC value of (+)-β-pinene. Finally, the cytotoxicity of the positive enantiomers of pinene to murine macrophages was evaluated, and 250 µg/mL of (+)-a-pinene and (+)-β-pinene reduced the cell viability to 66.8% and 57.7%, respectively.

https://www.mdpi.com/1420-3049/17/6/6305/pdf

Biological activities of α-pinene and β-pinene enantiomers.

Chemical composition, antimicrobial, antioxidant and antitumor activity of Thymus serpyllum L., Thymus algeriensis Boiss. and Reut and Thymus vulgaris L. essential oils

Ten essential oils, namely, mint (Mentha spicata L., Lamiaceae), ginger (Zingiber officinale Rosc., Zingiberaceae), lemon (Citrus limon Burm.f., Rutaceae), grapefruit (Citrus paradisi Macf., Rutaceae), jasmine (Jasminum grandiflora L., Oleaceae), lavender (Mill., Lamiaceae), chamomile (Matricaria chamomilla L., Compositae), thyme (Thymus vulgaris L., Lamiaceae), rose (Rosa damascena Mill., Rosaceae) and cinnamon (Cinnamomum zeylanicum N. Lauraceae) were tested for their antibacterial activities towards Propionibacterium acnes and in vitro toxicology against three human cancer cell lines. Thyme, cinnamon and rose essential oils exhibited the best antibacterial activities towards P. acnes, with inhibition diameters of 40 +/- 1.2 mm, 33.5 +/- 1.5 mm and 16.5 +/- 0.7 mm, and minimal inhibitory concentrations of 0.016% (v/v), 0.016% (v/v) and 0.031% (v/v), respectively. Time-kill dynamic procedures showed that thyme, cinnamon, rose, and lavender essential oils exhibited the strongest bactericidal activities at a concentration of 0.25% (v/v), and P. acnes was completely killed after 5 min. The thyme essential oil exhibited the strongest cytotoxicity towards three human cancer cells. Its inhibition concentration 50% (IC(50)) values on PC-3, A549 and MCF-7 tumor cell lines were 0.010% (v/v), 0.011% (v/v) and 0.030% (v/v), respectively. The cytotoxicity of 10 essential oils on human prostate carcinoma cell (PC-3) was significantly stronger than on human lung carcinoma (A549) and human breast cancer (MCF-7) cell lines.

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Activities of Ten Essential Oils towards Propionibacterium acnes and PC-3, A-549 and MCF-7 Cancer Cells

Nigella sativa (N. sativa) seed has been an important nutritional flavoring agent and natural remedy for many ailments for centuries in ancient systems of medicine, e.g. Unani, Ayurveda, Chinese and Arabic Medicines. Many active components have been isolated from N. sativa, including thymoquinone, thymohydroquinone, dithymoquinone, thymol, carvacrol, nigellimine-N-oxide, nigellicine, nigellidine and alpha-hederin. In addition, quite a few pharmacological effects of N. sativa seed, its oil, various extracts and active components have been identified to include immune stimulation, anti-inflammation, hypoglycemic, antihypertensive, antiasthmatic, antimicrobial, antiparasitic, antioxidant and anticancer effects. Only a few authors have reviewed the medicinal properties of N. sativa and given some description of the anticancer effects. A literature search has revealed that a lot more studies have been recently carried out related to the anticancer activities of N. sativa and some of its active compounds, such as thymoquinone and alpha-hederin. Acute and chronic toxicity studies have recently confirmed the safety of N. sativa oil and its most abundant active component, thymoquinone, particularly when given orally. The present work is aimed at summarizing the extremely valuable work done by various investigators on the effects of N. sativa seed, its extracts and active principles against cancer. Those related to the underlying mechanism of action, derivatives of thymoquinone, nano thymoquinone and combinations of thymoquinone with the currently used cytotoxic drugs are of particular interest. We hope this review will encourage interested researchers to conduct further preclinical and clinical studies to evaluate the anticancer activities of N. sativa, its active constituents and their derivatives.

Anticancer Activity of Nigella sativa (Black Seed) — A Review

Summary Over many centuries humans have been mining the bounties of nature for discovering substances that have been used for the treatment of all human diseases; many such remedies are useful even today as modern day medicine. Emerging evidence also suggests that the search is still continuing for harnessing active compounds from nature in combating human illnesses although pharmaceutical industries are equally active for synthesizing small molecule compounds as novel therapeutics. The lesson learned over many centuries clearly suggests that further sophisticated search for finding compounds from natural resources together with robust characterization and chemical synthesis will lead to the discovery of novel drugs that may have high therapeutic efficacy against all human diseases including cancer. Black cumin seed (Nigella sativa) oil extracts have been used for many centuries for the treatment of many human illnesses, and more recently the active compound found in black seed oil, viz. thymoquinone (TQ) has been tested for its efficacy against several diseases including cancer. However, further research is needed in order to assess the full potential of TQ as a chemopreventive and/or therapeutic agent against cancers. Here, we have summarized what is known regarding the value of black seed oil and its active compound TQ, and how this knowledge will help us to advance further research in this field by creating awareness among scientists and health professionals in order to appreciate the medicinal value of TQ and beyond.

From here to eternity - the secret of Pharaohs: Therapeutic potential of black cumin seeds and beyond.

The objective of the present study was to evaluate the in vitro and invivo anti-cancer effect of Nigella sativa L. seed extracts. The essentialoil (IC 50 = 0.6%, v/v) and ethyl acetate (IC 50 = 0.75%) extracts weremore cytotoxic against the P815 cell line than the butanol extract (IC 50 = 2%). Similar results were obtained with the Vero cell line. Althoughall extracts had a comparable cytotoxic effect against the ICO1 cellline, with IC 50 values ranging from 0.2 to 0.26% (v/v), tests on theBSR cell line revealed a high cytotoxic effect of the ethyl acetateextract (IC 50 = 0.2%) compared to the essential oil (IC 50 = 1.2%).These data show that the cytotoxicity of each extract depends on thetumor cell type. In vivo , using the DBA2/P815 (H 2d ) mouse model, ourresults clearly showed that the injection of the essential oil into thetumor site significantly inhibited solid tumor development. Indeed, onthe 30th day of treatment, the tumor volume of the control animals was2.5 ± 0.6 cm

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Anti-tumor properties of blackseed (Nigella sativa L.) extracts

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 cm(3) after injection with 10, 30, or 50 microL per 72 h (six times), respectively, as opposed to 3.88 +/- 0.50 cm(3) 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.

/pdf/cytotoxic-effect-of-essential-oil-of-thyme-thymus-2it13vycu7.pdf

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

Study on the antinociceptive effects of Thymus broussonetii Boiss extracts in mice and rats.

In our previous work, we have demonstrated that Thymus broussonetii exerts a significant analgesic activity, which was more potent than the reference analgesic drug (acetyl salicylic acid; ASA). In this study, we examined the antinociceptive effect of three Moroccan Thyme species, i.e. Thymus satureioides, Thymus maroccanus and Thymus leptobotrys. The effect of aqueous, butanolic and ethyl acetate extracts of each species were tested on the nociceptive response in mice using a formalin test as a model of nociception. The results obtained showed that the treatment with aqueous and butanolic extracts (50, 100, 200 and 300 mg/kg, i.p.) of the three species induced a marked inhibition of the nociceptive response in both neurogenic and inflammatory phases of formalin test. The ethyl acetate extracts had a weak effect on the neurogenic phase, but it had a significant effect on the inflammatory phase. These results suggest that the aqueous and butanolic extracts act both peripherally and centrally to inhibit the nociceptive response, while the ethyl acetate extracts act rather peripherally. According to ID50 values and the maximal inhibition of the nociceptive behaviour, we could conclude that T. satureioides was more potent and efficacious in inhibiting the formalin nociceptive response. Phytochemical screening carried out on these species showed the presence of quinons, saponins, tannins, terpenes and flavonoids. Our results provide evidence that T. satureioides, T. maroccanus and T. leptobotrys possess active principles that exhibit marked analgesic effect, thus confirming and justifying the popular uses of these plants to relieve some pains.

A. Dalal

Papers

Anti-tumor properties of blackseed (Nigella sativa L.) extracts

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

Study on the antinociceptive effects of Thymus broussonetii Boiss extracts in mice and rats.

Analgesic activity of three thyme species, Thymus satureioides, Thymus maroccanus and Thymus leptobotrys