Sesquiterpenoids from myrrh inhibit androgen receptor expression and function in human prostate cancer cells

Recent advances in dietary androgen receptor inhibitors

As a nuclear transcription factor, the androgen receptor (AR) plays a crucial role not only in normal male sexual differentiation and growth of the prostate, but also in benign prostatic hyperplasia, prostatitis, and prostate cancer. Multiple population-based epidemiological studies demonstrated that prostate cancer risk was inversely associated with increased dietary intakes of green tea, soy products, tomato, and so forth. Therefore, this review aimed to summarize the structure and function of AR, and further illustrate the structural basis for antagonistic mechanisms of the currently clinically available antiandrogens. Due to the limitations of these antiandrogens, a series of natural AR inhibitors have been identified from edible plants such as fruits and vegetables, as well as folk medicines, health foods, and nutritional supplements. Hence, this review mainly focused on recent experimental, epidemiological, and clinical studies about natural AR inhibitors, particularly the association between dietary intake of natural antiandrogens and reduced risk of prostatic diseases. Since natural products offer multiple advantages over synthetic antiandrogens, this review may provide a comprehensive and updated overview of dietary-derived AR inhibitors, as well as their potential for the nutritional intervention against prostatic disorders.

The multifaceted therapeutic value of targeting steroid receptor coactivator-1 in tumorigenesis

Steroid receptor coactivator-1 (SRC-1, also known as NCOA1) frequently functions as a transcriptional coactivator by directly binding to transcription factors and recruiting to the target gene promoters to promote gene transcription by increasing chromatin accessibility and promoting the formation of transcriptional complexes. In recent decades, various biological and pathological functions of SRC-1 have been reported, especially in the context of tumorigenesis. SRC-1 is a facilitator of the progression of multiple cancers, including breast cancer, prostate cancer, gastrointestinal cancer, neurological cancer, and female genital system cancer. The emerging multiorgan oncogenic role of SRC-1 is still being studied and may not be limited to only steroid hormone-producing tissues. Growing evidence suggests that SRC-1 promotes target gene expression by directly binding to transcription factors, which may constitute a novel coactivation pattern independent of AR or ER. In addition, the antitumour effect of pharmacological inhibition of SRC-1 with agents including various small molecules or naturally active compounds has been reported, but their practical application in clinical cancer therapy is very limited. For this review, we gathered typical evidence on the oncogenic role of SRC-1, highlighted its major collaborators and regulatory genes, and mapped the potential mechanisms by which SRC-1 promotes primary tumour progression.

The Role of Myrrh Metabolites in Cancer, Inflammation, and Wound Healing: Prospects for a Multi-Targeted Drug Therapy

Background: Myrrh extract is a well-known medicinal plant with significant therapeutic benefits attributed to the activity of its diverse metabolites. It has promising activity against cancer and inflammatory diseases, and could serve as a potential therapeutic alternative since most therapeutic agents have severe side effects that impair quality of life. Method: The current study identified the active metabolites from the myrrh resin methanolic extract. Then, the extracts were tested for in vitro anti-inflammatory and anti-cancer activity using cancer cell lines and Tamm-Horsfall Protein 1 (Thp-1)-like macrophage cell lines. Furthermore, using an in vivo rat model, the extracts’ anti-inflammatory and wound-healing activity was investigated. In addition, in silico predictions of the myrrh constituents highlighted the pharmacokinetic properties, molecular targets, and safety profile, including cytochrome P 450 (CYP) inhibition and organ toxicity. Results: Nine secondary metabolites were identified, and computational predictions suggested a good absorption profile, anticancer, anti-inflammatory, and wound-healing effects. The myrrh extract had moderate cytotoxic activity against both HL60 and K562 leukemia cell lines and the KAIMRC1 breast cancer cell line. Myrrh caused a dose-dependent effect on macrophages to increase the reactive oxygen species (ROS) levels, promote their polarization to classically activated macrophages (M1) and alternatively activated macrophages (M2) phenotypes, and consequently induce apoptosis, highlighting its ability to modulate macrophage function, which could potentially aid in several desired therapeutic processes, including the resolution of inflammation, and autophagy which is an important aspect to consider in cancer treatment. The topical application of myrrh improved wound healing, with no delayed inflammatory response, and promoted complete re-epithelization of the skin, similar to the positive control. In conclusion, we provide evidence for the methanolic extract of myrrh having cytotoxic activity against cancer cells and anti-inflammatory wound-healing properties, which may be attributed to its role in modulating macrophage function. Furthermore, we suggest the active constituents responsible for these properties, which warrants further studies focusing on the precise roles of the active metabolites.

Paclitaxel and Myrrh oil Combination Therapy for Enhancement of Cytotoxicity against Breast Cancer; QbD Approach

Paclitaxel (PX), plant alkaloid, is a chemotherapeutic agent intended for treating a wide variety of cancers. The objective of the present study was to formulate and evaluate the anticancer activity of PX loaded into a nanocarrier, mainly PEGylated nanoemulsion (NE) fabricated with myrrh essential oil. Myrrh essential oil has been estimated previously to show respectable anticancer activity. Surface modification of the formulation with PEG-DSPE would help in avoiding phagocytosis and prolong the residence time in blood circulation. Various NE formulations were developed after operating (22) factorial design, characterized for their particle size, in vitro release, and hemolytic activity. The optimized formula was selected and compared to its naked counterpart in respect to several characterizations. Quantitative amount of protein absorbed on the formulation surfaces and in vitro release with and without serum incubation were evaluated. Ultimately, MTT assay was conducted to distinguish the anti-proliferative activity. PEGylated PX-NE showed particle size 170 nm, viscosity 2.91 cP, in vitro release 57.5%, and hemolysis 3.44%, which were suitable for intravenous administration. A lower amount of serum protein adsorbed on PEGylated PX-NE surface (16.57 µg/µmol) compared to naked counterpart (45.73 µg/µmol). In vitro release from PEGylated NE following serum incubation was not greatly affected (63.3%), in contrast to the naked counterpart (78.8%). Eventually, anti-proliferative effect was obtained for PEGylated PX-NE achieving IC50 38.66 µg/mL. The results obtained recommend PEGylated NE of myrrh essential oil as a candidate nanocarrier for passive targeting of PX.

In vitro cytogenotoxic and mutagenic effects of Commiphora myrrha essential oil

Commiphora myrrha, located in the tropical zone, is a widely used tree for medicinal purposes in the Arabian Peninsula and a large part of Africa. In this research, cytogenotoxic effects of the commercially available Commiphora myrrha essential oil (myrrh) were studied using micronucleus (MN), comet, and total oxidant (TOS), and total antioxidant (TAS) assays on human peripheral lymphocytes under in vitro conditions. In addition, pure pBR322 plasmid DNA was used to investigate DNA damaging/protecting activity of the essential oil. Finally, a bacterial reversion (Ames) test was performed using Salmonella typhimurium mutant strains TA98 and TA100 to determine the potential effect of the agent in the induction of gene mutations. The high concentration of Commiphora myrrha (0.125 µL/mL) induced MN formation significantly compared to the untreated control in both treatment times (24 or 48 h). Only at the highest concentration, nuclear division index (NDI) values were found lower than the controls. In the Comet test performed on healthy lymphocytes, only the highest concentration of myrrh caused significant increases in the percentage of damaged cells and genetic damage index (GDI) values. Myrrh oil showed no significant mutagenic effect on mutant Salmonella strains. In addition, the substance did not directly damage plasmid DNA but also protected DNA against damaging factors such as H₂O₂ and UV. Finally, in the TAS and TOS assays, no significant differences on the oxidative stress parameters were found in cell culture compared to the control. The results of this study showed that myrrh oil exerts cytogenotoxic risk only at higher concentrations.

Mechanism-based inactivation of cytochrome P450 enzymes by natural products based on metabolic activation

Cytochrome P450 enzymes (P450 enzymes) are the most common and important phase I metabolic enzymes and are responsible for the majority of the metabolism of clinical drugs and other xenobiotics. Drug-drug interactions (DDIs) can occur when the activities of P450 enzymes are inhibited. In particular, irreversible inhibition of P450 enzymes may lead to severe adverse interactions, compared to reversible inhibition. Many natural products have been shown to be irreversible inhibitors of P450 enzymes. The risks for intake of naturally occurring irreversible P450 enzyme inhibitors have been rising due to the rapid growth of the global consumption of natural products. Irreversible inhibition is usually called mechanism-based inactivation, which is time-, concentration- and NADPH- dependent. Generally, the formation of electrophilic intermediates is fundamental for the inactivation of P450 enzymes. This review comprehensively classifies natural P450 enzyme inactivators, including terpenoids, phenylpropanoids, flavonoids, alkaloids, and quinones obtained from herbs or foods. Moreover, the structure - activity correlations according to the IC₅₀ (or K_i) values reported in the literature as well as the underlying mechanisms based on metabolic activation are highlighted in depth.

Sesquiterpenes and their derivatives-natural anticancer compounds: An update

Sesquiterpenes belong to the largest group of plant secondary metabolites, which consist of three isoprene building units. These compounds are widely distributed in various angiosperms, a few gymnosperms and bryophytes. Sesquiterpenes and their allied derivatives are bio-synthesized in various plant parts including leaves, fruits and roots. These plant-based metabolites are predominantly identified in the Asteraceae family, wherein up to 5000 complexes have been documented to date. Sesquiterpenes and their derivatives are characteristically associated with plant defence mechanisms owing to their antifungal, antibacterial and antiviral activities. Over the last two decades, these compounds have been reportedly demonstrated health promoting perspectives against a wide range of metabolic syndromes i.e. hyperglycemia, hyperlipidemia, cardiovascular complications, neural disorders, diabetes, and cancer. The high potential of sesquiterpenes and their derivatives against various cancers like breast, colon, bladder, pancreatic, prostate, cervical, brain, liver, blood, ovarium, bone, endometrial, oral, lung, eye, stomach and kidney are the object of this review. Predominantly, it recapitulates the literature elucidating sesquiterpenes and their derivatives while highlighting the mechanistic approaches associated with their potent anticancer activities such as modulating nuclear factor kappa (NF-kB) activity, inhibitory action against lipid peroxidation and retarding the production of reactive oxygen & nitrogen species (ROS&RNS).

Myrrh induces the apoptosis and inhibits the proliferation and migration of gastric cancer cells through down-regulating cyclooxygenase-2 expression

OBJECTIVE

The present study is designed to evaluate the anti-tumor effects of myrrh on human gastric cancer both in vitro and in vivo.

METHODS

The gastric cancer cell proliferation was determined by MTT assay. Apoptosis was measured by flow cytometry and Hoechst 33342 staining. Wound healing was performed to evaluate the effects of myrrh on the migration. COX-2, PCNA, Bcl-2, and Bax expressions were detected by Western blot analysis. A xenograft nude mice model of human gastric cancer was established to evaluate the anti-cancer effect of myrrh in vivo.

RESULTS

Myrrh significantly inhibited cellular proliferation, migration, and induced apoptosis in vitro as well as inhibited tumor growth in vivo. In addition, myrrh inhibited the expression of PCNA, COX-2, and Bcl-2 as well as increased Bax expression in gastric cancer cells.

CONCLUSION

Myrrh may inhibit the proliferation and migration of gastric cancer cells, as well as induced their apoptosis by down-regulating the expression of COX-2.

Efficacy and safety of myrrh in patients with incomplete abortion: a randomized, double-blind, placebo-controlled clinical study

BACKGROUND

Myrrh (Commiphora myrrha (Nees) Engl.) has a long history of traditional use as a herbal medicine for different purposes. In ancient traditional Persian manuscripts, it has been noted that myrrh may act as uterine stimulant and probably cause complete abortion. However, there is no evidence to verify this comment. Therefore, the current study was carried out to evaluate the efficacy and safety of Myrrh in the treatment of incomplete abortion.

MATERIALS AND METHODS

In a randomized double-blinded placebo controlled clinical trial, 80 patients with ultrasound-documented retained products of conception (RPOC) were assigned to receive capsules containing 500 mg of Myrrh oleo-gum-resin or a placebo three times a day for 2 weeks. The existence of the retained tissue and its size were evaluated by ultrasound examination at the beginning and end of the study.

RESULTS

After 2 weeks, the mean diameter of the RPOC in the Myrrh group was significantly reduced compared with the placebo group (P < 0.001). Meanwhile, the rate of successful complete abortion was 82.9% in the intervention group and 54.3% in the placebo group (P = 0.01). The patients in both groups reported no serious drug-related adverse effects.

CONCLUSION

This study shows that Myrrh is effective and safe in the resolution of the RPOC and may be considered as an alternative option for treatment of patients with incomplete abortion. However, further studies on active compounds isolated from myrrh and their uterine stimulant effects are needed.

TRIAL REGISTRATION

This study was retrospectively registered at Iranian Registry of Clinical Trials (www.irct.ir) IRCT code: IRCT20140317017034N7.

Phytochemical Constituents of Guggul and their Biological Qualities

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In the herbal drug pharmaceutical industry, guggul is enjoying emergent consumer acceptance around the world. In the Indian market, more than fifty formulations of guggul have been introduced by well-known brands including Himalaya, Patanjali and Baidyanath Pharmaceuticals. Basically, guggul is the gum resin from Commiphora wightii (syn. Commiphora Mukul). It has been used to treat various ailments including obesity, osteoarthritis, arthritis, constipation, liver disorders, inflammation, anemia, diabetes, etc. Including medicinal properties, it is used as a good binding agent and mixed in various herbal formulations. To review the major phytochemical, medicinal properties and analytical methods involved in the detection of guggul by using the exhaustive bibliographic research by means of various scientific engines and databases. Guggul contained approximately 66 phytochemical including gallic acid, quercetin, and guggulsterones E and Z. These phytochemicals have a wide range of pharmacological activities such as antioxidant, antibacterial, antimutagenic, antivenom and antitumor. It has been noticed that the mode of action of guggulsterone has not been fully explored. Pharmacology and toxicological studies are very few. These works have shown huge literature gap, which is to be fulfilled through the detailed in-vivo and in-vitro studies.

Frankincense and myrrh and their bioactive compounds ameliorate the multiple myeloma through regulation of metabolome profiling and JAK/STAT signaling pathway based on U266 cells

BACKGROUND

Frankincense and myrrh are used as traditional anti-inflammatory and analgesic medicines in China. It has been reported that frankincense and myrrh have significant anti-tumor activities. The present study was designed to investigate the inhibitory efficacy of frankincense ethanol extracts (RXC), myrrh ethanol extracts (MYC), frankincense -myrrh ethanol extracts (YDC), frankincense -myrrh water extracts (YDS) and their main compounds on U266 human multiple myeloma cell line.

METHODS

The inhibition effects of cell proliferation was evaluated by MTT assays. Cell culture supernatant was collected for estimation of cytokines. Western blot analysis was designed to investigate the regulatory of JAK/STAT signal pathway. In addition, cell metabolomics based on the ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS) had been established to investigate the holistic efficacy of frankincense and myrrh on U266 cells. Acquired data were processed by partial least-squares discriminant analysis (PLS-DA) and orthogonal projection to latent structures squares-discriminant analysis (OPLS-DA) to identify potential biomarkers.

RESULTS

RXC, MYC significantly inhibited the proliferation of U266 cells at dose of 25-400 μg/mL, YDC and YDS at the dose of 12.5-400 μg/mL. 3-O-acetyl-α-boswellic acid, 3-acetyl-11 keto-boswellic acid and 11-keto-boswellic acid had the most significant anti- multiple myeloma activities in the 10 compounds investigated, therefore these 3 compounds were selected as representatives for Elisa assay and western blotting experiments. All the extracts and active compounds ameliorated the secretion of cytokines and down-regulated the expression of JAK/STAT signaling pathway-related proteins. Comparing RXC, MYC, YDC and YDS-treated U266 cells with vehicle control (DMSO), 13, 8, 7, 7 distinct metabolites and 2, 2, 3, 0 metabolic target pathways involved in amino acid metabolism, lipid metabolism, vitamin metabolism, arachidonic acid were identified, respectively.

CONCLUSIONS

Taken together our results suggest that the frankincense and myrrh and their bioactive compounds inhibit proliferation of U266 multiple myeloma cells by regulating JAK/STAT signaling pathway and cellular metabolic profile.

The genus Commiphora: a review of its traditional uses, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

The resinous exudates of the Commiphora species, known as 'myrrh', are used in traditional Chinese medicine for the treatment of trauma, arthritis, fractures and diseases caused by blood stagnation. Myrrh has also been used in the Ayurvedic medical system because of its therapeutic effects against inflammatory diseases, coronary artery diseases, gynecological disease, obesity, etc.

AIM OF THE REVIEW

Based on a comprehensive review of traditional uses, phytochemistry, pharmacological and toxicological data on the genus Commiphora, opportunities for the future research and development as well as the genus' therapeutic potential are analyzed.

METHODS

Information on the Commiphora species was collected via electronic search (using Pubmed, SciFinder, Scirus, Google Scholar and Web of Science) and a library search for articles published in peer-reviewed journals. Furthermore, information also was obtained from some local books on ethnopharmacology. This paper covers the literature, primarily pharmacological, from 2000 to the end of December 2011.

RESULTS

The resinous exudates from the bark of plants of the genus Commiphora are important indigenous medicines, and have a long medicinal application for arthritis, hyperlipidemia, pain, wounds, fractures, blood stagnation, in Ayurvedic medicine, traditional Chinese medicine and other indigenous medical systems. Phytochemical investigation of this genus has resulted in identification of more than 300 secondary metabolites. The isolated metabolites and crude extract have exhibited a wide of in vitro and in vivo pharmacological effects, including antiproliferative, antioxidant, anti-inflammatory and antimicrobial. The bioactive steroids guggulsterones have attracted most attention for their potent hypolipidemic effect targeting farnesoid X receptor, as well as their potent inhibitory effects on tumor cells and anti-inflammatory efficiency.

CONCLUSIONS

The resins of Commiphora species have emerged as a good source of the traditional medicines for the treatment of inflammation, arthritis, obesity, microbial infection, wound, pain, fractures, tumor and gastrointestinal diseases. The resin of C. mukul in India and that of C. molmol in Egypt have been developed as anti-hyperlipidemia and antischistosomal agents. Pharmacological results have validated the use of this genus in the traditional medicines. Some bioassays are difficult to reproduce because the plant materials used have not been well identified, therefore analytical protocol and standardization of extracts should be established prior to biological evaluation. Stem, bark and leaf of this genus should receive more attention. Expansion of research materials would provide more opportunities for the discovery of new bioactive principles from the genus Commiphora.

Steroids from Commiphora mukul display antiproliferative effect against human prostate cancer PC3 cells via induction of apoptosis

Two new stigmastane-type steroids, stigmasta-5,22E-diene-3β,11α-diol (1) and stigmasta-5,22E-diene-3β,7α,11α-triol (2), together with eight known compounds, were isolated from the resinous exudates of Commiphora mukul. Their structures were established by extensive analysis of their HR-MS, 1D- and 2D-NMR (COSY, HMQC, HMBC and NOESY) spectra. The isolates were evaluated for their antiproliferative activities against four human cancer cell lines. Compound 2 demonstrated inhibitory effects with IC(50) values of 5.21, 9.04, 10.94 and 16.56 μM, respectively, against K562, MCF-7, PC3 and DU145 human cancer cell lines. Further study showed that 2 was able to enforce the PC3 cell cycle arrest in the G2/M phase, and induce the apoptosis of PC3 cells by activation of Bax, caspases 3 and 9, and by inhibition of Bcl-2. It was also found that 1 inhibited proliferation of PC3 cells via G0/G1 phase arrest of the cell cycle.

One size fits all in prostate cancer: a story tale whose time has come and gone

The touchstone to evaluate accurately the aggressiveness and invasiveness of prostate cancer is something of a holy grail in the facet of urologic oncology. Gene expression and sequencing studies have improved our interpretations of the genetic determinants of the disease but are unsuccessful in the establishment of any unified classification to improve the molecular stratification. These questions addressing failure in rational drug design are difficult to answer in the multifaceted and heterogeneous pathogenesis of prostate cancer. In this review, we have developed a roadmap of the "recalcitrant prostate cancer proteome" to recognize the aspects of prostate cancer that may be helpful in effectively translating these findings to the clinic.