Growth inhibitory, apoptotic and anti-inflammatory activities displayed by a novel modified triterpenoid, cyano enone of methyl boswellates

Therapeutic potential of boswellic acids: an update patent review (2016-2023)

INTRODUCTION

Boswellic acids (BAs) are a group of pentacyclic triterpenoids of the ursane and oleanane type. They have shown very interesting biological properties that have led to the development of a number of synthesis protocols. Both natural BAs and their synthetic derivatives may be useful in the treatment of a variety of cancers, viral infections and inflammatory diseases.

AREAS COVERED

This review covers patents relating to the therapeutic activities of natural BAs and their synthetic derivatives. The latest patented studies of boswellic acids (are summarized by using the keywords 'boswellic acid,' in SciFinder, PubMed, and Google Patents and databases in the year from 2016 to 2023.

EXPERT OPINION

Boswellic acids have shown potent antiviral, anticancer and anti-inflammatory potential. Few BAs analogues have been prepared by modification at the C24-CO2H functional groups. In particular, the C-24 amide and amino analogues have shown enhanced anticancer effects compared to the parent AKBA. In addition, BAs have the ability to form conjugates with other antiviral, anti-inflammatory and anticancer drugs that synergistically enhance their biological efficacy. In addition, this conjugation strategy will increase the solubility and bioavailability of BAs, which is one of the most important issues in the development of BAs.

Synthesis of Novel Acetyl-11-keto-β-boswellic Acid Derivatives as Potential Anti-GBM Agents

Acetyl-11-keto-β-boswellic acid (AKBA) is known to inhibit the growth of glioblastoma (GBM) cells and subcutaneous GBM. A series of acetyl-11-keto-β-boswellic acid (AKBA) derivatives containing the oxime-ester functionality or amide side chains were synthesized, and their anti-GBM activities were evaluated. Some of these compounds exhibited significant inhibitory activity against cell proliferation in U87 and U251 GBM cell lines, with IC50 values in the micromolar concentration range. Cellular thermal shift analysis showed that A-01 and A-10 improved the thermal stability of FOXM1, indicating that these highly active compounds may directly bind to FOXM1 in cells. Docking studies of the two most active compounds, A-01 and A-10, revealed key interactions between these compounds and the active site of FOXM1, in which the amide moiety at the C-24 position was essential for improving the activity. These results suggested that A-10 is a suitable lead molecule for the development of FOXM1 inhibitors. Thus, the rational design of AKBA derivatives with amide side chains holds significant potential for discovering of a new class of triterpenoids capable of inhibiting GBM cell proliferation.

Anti-cancer properties of boswellic acids: mechanism of action as anti-cancerous agent

With the advent of highly effective plant-based medications with few or no side effects, the use of phytomedicines against complex diseases such as cancer is becoming more widespread. The broadly recognized pentacyclic triterpenes known as boswellic acids (BAs) are derived from the oleogum resin, or frankincense, extracted from the plant species of the genus Boswellia. The frankincense mixture contains various BA types, each having a different potential and helping treat certain cancers. This review focuses on details regarding the traits of the BAs, their roles as anti-cancer agents, the mechanism underlying their activities, and the function of their semi-synthetic derivatives in managing and treating certain cancers. The review also explores the biological sources of BAs, how they are conserved, and how biotechnology might help preserve and improve in vitro BA production. The review concludes that the BAs and their semi-synthetic derivatives are effective against a broad spectrum of cancer cell lines. The detailed information in the review can be helpful for researchers to gain more information about BAs and BA-based medications for efficient and cost-effective cancer treatments.

Discovery of carbamate-based N-salicyloyl tryptamine derivatives as novel pleiotropic agents for the treatment of Alzheimer's disease

In this work, based on the potential anti-AD molecule previously studied by our group, we continue to introduce different substituents at different positions to improve both drug-like properties and on target activities. 33 N-salicyloyl tryptamine-carbamate hybrids were designed, synthesized and evaluated as cholinesterase inhibitors. H327 was the most potent BChE inhibitor (eqBChE IC₅₀ = 0.057 ± 0.005 μM), and showed threefold improved inhibitory potency than the positive drug rivastigmine (eqBChE IC₅₀ = 0.19 ± 0.001 μM). In addition, H327 as a pseudo-irreversible BChE inhibitor was endowed with neuroprotective, antioxidative and anti-neuroinflammatory properties. Cytotoxicity and acute toxicity tests confirmed the safety of compound H327. The pharmacokinetics study showed that compound H327 had a longer T_1/2 time and higher bioavailability than the lead compound 1 g. Compound H327 was able to cross the blood-brain barrier (BBB) in vivo. Moreover, the behavioral tests showed that compound H327 could significantly improve scopolamine-induced cognitive impairment in vivo. Overall, these results demonstrated that compound H327 is a promising multi-target agent for the treatment of AD.

Boswellia serrata Extract as an Antibiofilm Agent against Candida spp

The use of antibiotics or antifungals to control infections caused by pathogenic microorganisms is currently insufficiently effective because of their emerging resistance. Thanks to the ability of microorganisms to form a biofilm and thus increase their resistance to administered drugs even more, modern medicine faces the task of finding novel substances to combat infections caused by them. In this regard, the effects of essential oils or plant extracts are often studied. Among the relatively neglected plants is Boswellia serrata, which has a high content of biologically active boswellic acids. In this study, we focused on one of the most common nosocomial infections, which are caused by Candida species. The most common representative is C. albicans, although the number of infections caused by non-albicans species has recently been increasing. We focused on the antifungal activity of Boswellia serrata extract Bioswellix against planktonic and adhering cells of Candida albicans, Candida parapsilosis and Candida krusei. The antifungal activity against adhering cells was further explored by determining the metabolic activity of cells (MTT) and determining the total amount of biofilm using crystal violet. Boswellic acid-containing plant extract was shown to suppress the growth of a suspension population of all tested Candida species. Boswellia serrata extract Bioswellix was most effective in inhibiting C. albicans biofilm formation.

Methanolic extract of Cucumis melo attenuates ethylene glycol-induced nephrolithiasis in Wistar rats

Evaluation of the effects of methanolic extract of Cucumis melo in ethylene glycol-induced nephrolithiasis on Wistar rats. 0.75% solution of ethylene glycol (EG) in payable water was given to produce nephrolithiasis on Wistar rats. The action of oral intake of methanolic extract of Cucumis melo seed in nephrolithiasis is studied and is matched with the action of oral intake of Cystone (standard) on Wistar rats. EG resulted in hyperoxaluria and deposition of calcium oxalate as well as raised urinary excretion of oxalate and calcium. Supplementation with methanolic extract of Cucumis melo seed decreased the increased renal oxalate, indicating a regulatory effect on oxalate formation endogenously. The outcomes stipulate that the seed of Cucumis melo is endowed with antinephrolithiatic action.

Perspectives on natural compounds in chemoprevention and treatment of cancer: an update with new promising compounds

Cancer is the second deadliest disease worldwide. Although recent advances applying precision treatments with targeted (molecular and immune) agents are promising, the histological and molecular heterogeneity of cancer cells and huge mutational burdens (intrinsic or acquired after therapy) leading to drug resistance and treatment failure are posing continuous challenges. These recent advances do not negate the need for alternative approaches such as chemoprevention, the pharmacological approach to reverse, suppress or prevent the initial phases of carcinogenesis or the progression of premalignant cells to invasive disease by using non-toxic agents. Although data are limited, the success of several clinical trials in preventing cancer in high-risk populations suggests that chemoprevention is a rational, appealing and viable strategy to prevent carcinogenesis. Particularly among higher-risk groups, the use of safe, non-toxic agents is the utmost consideration because these individuals have not yet developed invasive disease. Natural dietary compounds present in fruits, vegetables and spices are especially attractive for chemoprevention and treatment because of their easy availability, high margin of safety, relatively low cost and widespread human consumption. Hundreds of such compounds have been widely investigated for chemoprevention and treatment in the last few decades. Previously, we reviewed the most widely studied natural compounds and their molecular mechanisms, which were highly exploited by the cancer research community. In the time since our initial review, many promising new compounds have been identified. In this review, we critically review these promising new natural compounds, their molecular targets and mechanisms of anticancer activity that may create novel opportunities for further design and conduct of preclinical and clinical studies.

Boswellic acids: privileged structures to develop lead compounds for anticancer drug discovery

Introduction: Cancer has been identified to be the second major cause of death internationally as exemplified by ca. 9.6 million deaths in 2018 along with ca. 18 million new patients in 2018 that have been recorded. Natural boswellic acids (BAs) and their source, frankincense, have been reported to possess in vitro and in vivo anticancer effects toward various cancer cells.Areas covered: This comprehensive review focuses on the importance of boswellic acids (BAs) for the establishment of future treatments of cancer. Moreover, potent semisynthetic derivatives of BAs have been described along with their mode of action. In addition, important structural features of the semisynthetic BAs required for cytotoxic effects are also discussed.Expert opinion: Numerous semisynthetic BAs illustrate excellent cytotoxic effects. Of note, compounds bearing cyanoenone moieties in ring A, endoperoxides and hybrids display increased and more potent cytotoxic effects compared with other semisynthetic BAs. Moreover, BAs have the potential to conjugate or couple with other anticancer compounds to synergistically increase their combined anticancer effects. In addition, to get derived BAs to become lead anticancer compounds, future research should focus on the preparation of ring A cyanoenones, endoperoxides, and C-24 amide analogs.

Antiproliferative effects of boswellic acid-loaded chitosan nanoparticles on human lung cancer cell line A549

Aim: In the present study boswellic acids-loaded chitosan nanoparticles were synthesized using ionic gelation technique. The influence of independent variables were studied and optimized on dependent variables using central composite design. Methodology & results: The designed nanoparticles were observed spherical in shape with an average size of 67.5-187.2 nm and have also shown an excellent entrapment efficiency (80.06 ± 0.48). The cytotoxicity assay revealed enhanced cytotoxicity for drug-loaded nanoparticles in contrast to the free drug having an IC₅₀ value of 17.29 and 29.59 μM, respectively. Flow cytometry confirmed that treatment of cells with 40 μg/ml had arrested 22.75 ± 0.3% at SubG₀ phase of the cell cycle when compared with untreated A459 cells. The observed results justified the boswellic acids-loaded chitosan nanoparticles were effective due to greater cellular uptake, sustained intercellular drug retention and enhanced antiproliferative effect by inducing apoptosis.

Antioxidant and anti-tumour activity of triterpenoid compounds isolated from Morchella mycelium

Triterpenoid compounds are important bioactivity materials. Morchella is an abundant medicinal fungi found worldwide. In this study, we optimised the isolation and purification of triterpenoid compounds from Morchella mycelium fermentation. The results showed that the triterpenoid compounds yield was 35.22 mg/g, and we also identified two triterpenoid compounds using high-performance liquid chromatography. In addition, we evaluated the anti-tumour and antioxidant activity of the products, and the results showed that triterpenoid compounds from Morchella mycelium fermentation showed good bioactivity. The IC₅₀ values of four cancer cell lines treated with the triterpenoid compounds for 48 h were 7.20, 14.96, 4.41, and 13.43 mg/mL, respectively. Morphological changes associated with the apoptosis of PC-3 cells were observed using confocal scanning laser microscopy after treatment with triterpenoid compounds for 48 and 72 h. The triterpenoid compounds also exhibited DPPH radical, hydroxyl, and ABTS-free radical scavenging activities in vitro. These results suggest that triterpenoid compounds from Morchella mycelium fermentation, which are found in functional foods and used in the field of pharmacology, might be excellent products for the treatment of cancer and age-related illnesses.

Deep insights into the response of human cervical carcinoma cells to a new cyano enone-bearing triterpenoid soloxolone methyl: a transcriptome analysis

Semisynthetic triterpenoids, bearing cyano enone functionality in ring A, are considered now as novel promising anti-tumor agents. However, despite the large-scale studies, their effects on cervical carcinoma cells and, moreover, mechanisms underlying cell death activation by such compounds in this cell type have not been fully elucidated. In this work, we attempted to reconstitute the key pathways and master regulators involved in the response of human cervical carcinoma KB-3-1 cells to the novel glycyrrhetinic acid derivative soloxolone methyl (SM) by a transcriptomic approach. Functional annotation of differentially expressed genes, analysis of their cis^- regulatory sequences and protein-protein interaction network clearly indicated that stress of endoplasmic reticulum (ER) is the central event triggered by SM in the cells. A range of key ER stress sensors and transcription factor AP-1 were identified as upstream transcriptional regulators, controlling the response of the cells to SM. Additionally, by using Gene Expression Omnibus data, we showed the ability of SM to modulate the expression of key genes involved in regulation of the high proliferative rate of cervical carcinoma cells. Further Connectivity Map analysis revealed similarity of SM's effects with known ER stress inducers thapsigargin and geldanamycin, targeting SERCA and Grp94, respectively. According to the molecular docking study, SM could snugly fit into the active sites of these proteins in the positions very close to that of both inhibitors. Taken together, our findings provide a basis for the better understanding of the intracellular processes in tumor cells switched on in response to cyano enone-bearing triterpenoids.

An Update on Pharmacological Potential of Boswellic Acids against Chronic Diseases

Natural compounds, in recent years, have attracted significant attention for their use in the prevention and treatment of diverse chronic diseases as they are devoid of major toxicities. Boswellic acid (BA), a series of pentacyclic triterpene molecules, is isolated from the gum resin of Boswellia serrata and Boswellia carteri. It proved to be one such agent that has exhibited efficacy against various chronic diseases like arthritis, diabetes, asthma, cancer, inflammatory bowel disease, Parkinson’s disease, Alzheimer’s, etc. The molecular targets attributed to its wide range of biological activities include transcription factors, kinases, enzymes, receptors, growth factors, etc. The present review is an attempt to demonstrate the diverse pharmacological uses of BA, along with its underlying molecular mechanism of action against different ailments. Further, this review also discusses the roadblocks associated with the pharmacokinetics and bioavailability of this promising compound and strategies to overcome those limitations for developing it as an effective drug for the clinical management of chronic diseases.

In vitro Antibacterial Effect of Hydroalcoholic Extract of Lawsonia inermis, Malva sylvestris, and Boswellia serrata on Aggregatibacter actinomycetemcomitans

Background:

Considering the increased rate of microbial resistance to antibiotics and chemical side effects of antibiotics and antiseptics used for the treatment of periodontal disease, there is a need for an alternative antimicrobial agent with fewer complications. Medicinal herbs have recently become popular as novel antimicrobial agents. This study aimed to assess the antibacterial effects of hydroalcoholic extracts of Lawsonia inermis, Malva sylvestris, and Boswellia serrata on Aggregatibacter actinomycetemcomitans.

Materials and Methods:

Hydroalcoholic extracts of the three medicinal plants were obtained by the maceration technique and A. actinomycetemcomitans was cultured. Antimicrobial efficacy of the three medicinal plants was compared with that of 0.2% chlorhexidine (CHX) according to the Clinical and Laboratory Standards Institute protocol using agar disc diffusion and broth microdilution techniques. All tests were repeated three times.

Results:

Hydroalcoholic extracts of all three plants had antimicrobial activity against A. actinomycetemcomitans. The minimum inhibitory concentration (MIC) of L. inermis, M. sylvestris, and B. serrata was 78.1, 156.2, and 1666 μg/mL with no significant difference between them. The MIC of CHX was 3.33 μg/mL, which was significantly higher than that of B. serrata extract.

Conclusion:

Given that further in vivo studies confirm other properties of these extracts and their safety in terms of cytotoxicity and mutagenicity, hydroalcoholic extracts of L. inermis and M. sylvestris may be used in mouthwashes or local delivery systems to affect periodontal biofilm.

Googling the Guggul (Commiphora and Boswellia) for Prevention of Chronic Diseases

Extensive research during last 2 decades has revealed that most drugs discovered today, although costs billions of dollars for discovery, and yet they are highly ineffective in their clinical response. For instance, the European Medicines Agency has approved 68 anti-cancer drugs, and out of which 39 has reached the market level with no indication of increased survival nor betterment of quality of life. Even when drugs did improve survival rate compared to available treatment strategies, most of these were found to be clinically insignificant. This is a fundamental problem with modern drug discovery which is based on thinking that most chronic diseases are caused by alteration of a single gene and thus most therapies are single gene-targeted therapies. However, extensive research has revealed that most chronic diseases are caused by multiple gene products. Although most drugs designed by man are mono-targeted therapies, however, those designed by "mother nature" and have been used for thousands of years, are "multi-targeted" therapies. In this review, we examine two agents that have been around for thousands of years, namely "guggul" from Commiphora and Boswellia. Although we are all familiar with the search engine "google," this is another type of "guggul" that has been used for centuries and being explored for its various biological activities. The current review summarizes the traditional uses, chemistry, in vitro and in vivo biological activities, molecular targets, and clinical trials performed with these agents.

Pharmacological evidences for cytotoxic and antitumor properties of Boswellic acids from Boswellia serrata

ETHNOPHARMACOLOGICAL RELEVANCE

Increasing research on traditional herbal medicines and their phytoconstituents has recognized their usefulness in complementary as adjuvant to chemotherapy in various types of cancers. The oleo-gum resin of Boswellia serrata tree is one such folk medicine, which has been traditionally used for religious, cosmetic as well as medical purposes since ages. The oleo-gum resin of the plant has been used in traditional medicine to treat variety of conditions including inflammatory diseases like arthritis, asthma, chronic pain, bowel conditions and many other diseases. This review presents an overview of scientific studies on cytotoxic and antitumor properties of B. serrata and its constituents.

MATERIALS AND METHODS

Literature search was carried out for activities of B. serrata and various isolated boswellic acids such as β-boswellic acid, 11-keto-β-boswellic acid and acetyl-11-keto-β-boswellic acid reported in various cancer types in vitro as well as in vivo.

RESULTS

The triterpenoidal fraction of B. serrata (containing boswellic acids) is responsible for the cytotoxic and antitumor properties. Among the screened compounds, 3-O-acetyl-11-keto-β-boswellic acid has been found to be most promising cytotoxic molecule. The cytotoxic and antitumor effects are mainly due to induction of apoptosis through caspase activation, increased Bax expression, NF-κB down regulation and induction of poly (ADP)-ribose polymerase (PARP) cleavage.

CONCLUSIONS

Boswellic acids appear to be promising candidates for anticancer drug development in future. However, further in vivo studies are needed. Studies in combination with clinically used anticancer drugs and QSAR studies on individual boswellic acid also need to be carried out.

A molecular web: endoplasmic reticulum stress, inflammation, and oxidative stress

Execution of fundamental cellular functions demands regulated protein folding homeostasis. Endoplasmic reticulum (ER) is an active organelle existing to implement this function by folding and modifying secretory and membrane proteins. Loss of protein folding homeostasis is central to various diseases and budding evidences suggest ER stress as being a major contributor in the development or pathology of a diseased state besides other cellular stresses. The trigger for diseases may be diverse but, inflammation and/or ER stress may be basic mechanisms increasing the severity or complicating the condition of the disease. Chronic ER stress and activation of the unfolded-protein response (UPR) through endogenous or exogenous insults may result in impaired calcium and redox homeostasis, oxidative stress via protein overload thereby also influencing vital mitochondrial functions. Calcium released from the ER augments the production of mitochondrial Reactive Oxygen Species (ROS). Toxic accumulation of ROS within ER and mitochondria disturbs fundamental organelle functions. Sustained ER stress is known to potentially elicit inflammatory responses via UPR pathways. Additionally, ROS generated through inflammation or mitochondrial dysfunction could accelerate ER malfunction. Dysfunctional UPR pathways have been associated with a wide range of diseases including several neurodegenerative diseases, stroke, metabolic disorders, cancer, inflammatory disease, diabetes mellitus, cardiovascular disease, and others. In this review, we have discussed the UPR signaling pathways, and networking between ER stress-induced inflammatory pathways, oxidative stress, and mitochondrial signaling events, which further induce or exacerbate ER stress.

Indiosides G-K: steroidal glycosides with cytotoxic and anti-inflammatory activities from Solanum violaceum

Five new steroidal glycosides (1-5) and nine known compounds were isolated from Solanum violaceum. Indiosides G (1) and H (2) are spirostene saponins with an iso-type F ring, indioside I (3) is a spirostane saponin, and indiosides J (4) and K (5) are unusual furostanol saponins with a deformed F ring. These structures represent rare naturally occurring steroidal skeletons. The structures of the new compounds were elucidated using 1D and 2D spectroscopic techniques and acid hydrolysis. Compounds 2, 3, and 7-9 exhibited cytotoxic activity against six human cancer cell lines (HepG2, Hep3B, A549, Ca9-22, MDA-MB-231, and MCF-7) with IC(50) values of 1.83-8.04 μg/mL. Steroidal saponins 3, 8, and 9 showed inhibitory effects on superoxide anion generation with IC(50) values of 2.84 ± 0.18, 0.62 ± 0.03, and 1.62 ± 0.59 μg/mL, respectively. Saponins 8 and 9 also inhibited elastase release with IC(50) values of 111.05 ± 7.37 and 4.04 ± 0.51 μg/mL, respectively. Structure-activity relationship correlations of these compounds with respect to cytotoxic and anti-inflammatory effects are discussed.