Piper cubeba demonstrates anti-estrogenic and anti-inflammatory properties

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.

Neuroprotective potential of lignan-rich fraction of Piper cubeba L. by improving antioxidant capacity in the rat's brain

Piper cubeba contains various types of lignans. These compounds have been found to have potential pharmacological activities, one being a neuroprotector through an antioxidant mechanism, especially in the brain. This study examined the antioxidant activity of the lignan-rich fraction of P. cubeba (LF) in rat brains. The rats were given LF (200 and 400 mg/kg), Vitamin C (200 mg/kg), and a carrier as the control group for one-week p.o. The following day, rat brains were collected for antioxidant tests, including examining lipid peroxide inhibition, superoxide dismutase and catalase activity, and determination of nitric oxide (NO) concentration. The phytochemical compounds were analyzed with thin-layer chromatography (TLC), ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS), and gas chromatography-mass spectrometry (GC-MS). Test results show that the LF of both doses of 200 and 400 mg/kg could significantly increase antioxidant activity in the brain by inhibiting lipid peroxidation. LF could also increase catalase, despite the decrease in superoxide dismutase activity. Reduction in NO only occurred in the LF-200 group, while LF-400 showed insignificant results compared to the control group. In conclusion, LF showed potential as an antioxidant in the brain and could be beneficial for treating neurological diseases.

Development of a Validated High-Performance Liquid Chromatography Method and Optimization of the Extraction of Lignans from Piper cubeba

Piper cubeba L. f. is a food seasoning, which contains secondary metabolites displaying several biological properties, such as cytotoxic, anti-inflammatory, and antiparasitic activities. The lignans (+)-dihydroclusin, (-)-clusin, (-)-cubebin, (-)-yatein, and (-)-haplomyrfolin were isolated, with (-)-haplomyrfolin reported for the first time in P. cubeba seeds. Chromatographic standards were used to develop a reliable reverse-phase high-performance liquid chromatography analytical method according to the Agência Nacional de Vigilância Sanitária and International Conference on Harmonization guidelines to quantitate these lignans in both P. cubeba seeds and their extracts. The extraction of the lignans was also optimized, with the best conditions being ultrasound-assisted extraction, with 84% aqueous ethanol for 38 min in a single extraction. This procedure allows for the extraction of more than 80% of the total lignans, which is better in comparison to other techniques, such as maceration and Soxhlet extraction.

Evaluation of lignan (-)-cubebin extracted from Piper cubeba on human colon adenocarcinoma cells (HT29)

The dibenzylbutyrolactone lignan (-)-cubebin, which is extracted from the seeds of the pepper Piper cubeba, has shown promise as an anti-inflammatory, analgesic, leishmanicidal, antiproliferative, and trypanocidal compound. Given the therapeutic potential of (-)-cubebin, this study aimed to investigate its safety profile by analyzing cytotoxicity, mutagenicity, cell proliferation kinetics, induction of apoptosis, and expression of pro-apoptotic genes in human colon adenocarcinoma cells (HT29) exposed to (-)-cubebin. MTT cytotoxicity assays demonstrated that (-)-cubebin was cytotoxic only at 280 µM, whereas it was not cytotoxic at 2.8, 14, or 28 µM. Data demonstrated that (-)-cubebin was not mutagenic as evidenced by a micronucleus (MN) assay, did not alter cell-growth kinetics over 4 d, and showed absence of induced apoptosis after 24 h. Further, CASP8 and CASP9 gene expression was not markedly changed in HT29 cells exposed to 28 µM or 70 µM (-)-cubebin for 12 h. Based on our observations, (-)-cubebin was cytotoxic at a concentration of 280 µM, suggesting that the use of this concentration should be avoided. However, lower concentrations exerted no apparent damaging effects, indicating that this lignan is safe to use for pharmacological purposes at certain concentrations.