Bulbophyllum sterile petroleum ether fraction induces apoptosis in vitro and ameliorates tumor progression in vivo

Ethnobotany, Phytochemistry, Biological Activities, and Health-Promoting Effects of the Genus Bulbophyllum

The genus Bulbophyllum is of scientific interest due to the phytochemical components and diverse biological activities found across species of the genus. Most Bulbophyllum species are epiphytic and located in habitats that range from subtropical dry forests to wet montane cloud forests. In many cultures, the genus Bulbophyllum has a religious, protective, ornamenting, cosmetic, and medicinal role. Detailed investigations into the molecular pharmacological mechanisms and numerous biological effects of Bulbophyllum spp. remain ambiguous. The review focuses on an in-depth discussion of studies containing data on phytochemistry and preclinical pharmacology. Thus, the purpose of this review was to summarize the therapeutic potential of Bulbophyllum spp. biocompounds. Data were collected from several scientific databases such as PubMed and ScienceDirect, other professional websites, and traditional medicine books to obtain the necessary information. Evidence from pharmacological studies has shown that various phytoconstituents in some Bulbophyllum species have different biological health-promoting activities such as antimicrobial, antifungal, antioxidant, anti-inflammatory, anticancer, and neuroprotective. No toxicological effects have been reported to date. Future clinical trials are needed for the clinical confirmation of biological activities proven in preclinical studies. Although orchid species are cultivated for ornamental purposes and have a wide traditional use, the novelty of this review is a summary of biological actions from preclinical studies, thus supporting ethnopharmacological data.

Orchidaceae-Derived Anticancer Agents: A Review

Simple Summary

Orchids are commonly used in folk medicine for the treatment of infections and tumors but little is known about the actual chemical composition of these plants and their anticancer properties. In this paper, the most recent literature on orchid-derived bioactive substances with anticancer properties is reviewed. According to the published data, numerous species of orchids contain potential antitumor chemicals. Still, a relatively insignificant number of species of orchids have been tested for their bioactive properties and most of those studies were on Asian taxa. Broader research, ’including American and African species, as well as the correct identification of samples, is essential for evaluating the usefulness of orchids as a plant family with huge anticancer potential.

Abstract

Species of orchids, which belong to the largest family of flowering plants, are commonly used in folk medicine for the treatment of infections and tumors. However, little is known about the actual chemical composition of these plants and their anticancer properties. In this paper, the most recent literature on orchid-derived bioactive substances with anticancer properties is reviewed. For the assessment, previous papers on the anticancer activity of Orchidaceae published since 2015 were considered. The papers were found by exploring electronic databases. According to the available data, many species of orchids contain potential antitumor chemicals. The bioactive substances in a relatively insignificant number of orchids are identified, and most studies are on Asian taxa. Broader research on American and African species and the correct identification of samples included in the experiments are essential for evaluating the usefulness of orchids as a plant family with vast anticancer potential.

Folium nelumbinis (Lotus leaf) volatile-rich fraction and its mechanisms of action against melanogenesis in B16 cells

This study was aimed at determining the influence of Folium nelumbinis (Lotus leaf) extracts on melanogenesis in vitro models of melanoma cell line. The anticancer activity of four fractions, including petroleum ether (PEE), n-hexane (HE), ethanol (EE), and ethyl acetate (EAE) from F. nelumbinis on B16 cell lines (C57BL/6J melanoma cell), were evaluated after 24 and 48 h treatment. Results showed that PEE as well as volatile-rich fractions of linolenic acid and linolenic acid ethyl ester significantly (p < 0.05) reduced tyrosinase activity and melanin content in B16 melanoma cells model. Meanwhile, PEE and its primarily contained compound triggered apoptosis of B16 cells in a dose-dependent way. These results demonstrated that PEE possessed effective activities against melanin and tyrosinase generations through the induction of apoptosis. Moreover, a relation between the volatile-rich fractions of F. nelumbinis and the anticancer effects was demonstrated as well.

Proanthocyanidin Polymer-Rich Fraction of Stryphnodendron adstringens Promotes in Vitro and in Vivo Cancer Cell Death via Oxidative Stress

Cervical cancer is the fourth most common cancer that affects women, mainly through human papilloma virus (HPV) infection with high-risk HPV16 and HPV18. The present study investigated the in vitro anticancer activity and mechanism of action of a proanthocyanidin polymer-rich fraction of Stryphnodendron adstringens (F2) in cervical cancer cell lines, including HeLa (HPV18-positive), SiHa (HPV16-positive), and C33A (HPV-negative) cells, and also evaluated in vivo anticancer activity. In vitro, cell viability was determined by the MTT assay. Cell migration was determined by the wound healing assay. The mechanism of action was investigated by performing ultrastructural analysis and evaluating reactive oxygen species (ROS) production, mitochondrial metabolism, lipoperoxidation, BCL-2 family expression, caspase expression, and DNA and cell membrane integrity. In vivo activity was evaluated using the murine Ehrlich solid tumor model. F2 time- and dose-dependently reduced cell viability and significantly inhibited the migration of cervical cancer cells. HeLa and SiHa cells treated with F2 (IC50) exhibited intense oxidative stress (i.e., increase in ROS and decrease in antioxidant species) and mitochondrial damage (i.e., mitochondrial membrane potential depolarization and a reduction of intracellular levels of adenosine triphosphate). Increases in the Bax/BCL-2 ratio and caspase 9 and caspase 3 expression, were observed, with DNA damage that was sufficient to trigger mitochondria-dependent apoptosis. Cell membrane disruption was observed in C33A cells (IC50 and IC90) and HeLa and SiHa cells (IC90), indicating progress to late apoptosis/necrosis. The inhibition of ROS production by N-acetylcysteine significantly suppressed oxidative stress in all three cell lines. In vivo, F2 significantly reduced tumor volume and weight of the Ehrlich solid tumor, and significantly increased lipoperoxidation, indicating that F2 also induces oxidative stress in the in vivo model. These findings indicate that the proanthocyanidin polymer-rich fraction of S. adstringens may be a potential chemotherapeutic candidate for cancer treatment.