Increased bioavailability of 11-keto-β-boswellic acid following single oral dose frankincense extract administration after a standardized meal in healthy male volunteers: modeling and simulation considerations for evaluating drug exposures

The anti-proliferative effects of a frankincense extract in a window of opportunity phase ia clinical trial for patients with breast cancer

PURPOSE

Boswellic acids, active components of frankincense, suppress tumor proliferation in vitro with a strong clinical trial safety profile in patients with inflammatory diseases. We performed a Phase Ia window of opportunity trial of Boswellia serrata (B. serrata) in patients with breast cancer to evaluate its biologic activity and safety.

METHODS

Patients with invasive breast cancer were treated pre-operatively with B. Serrata (2400 mg/day PO) until the night before surgery for a median of 11 days (SD 6 days; range: 5-23 days). Paraffin-embedded sections from pretreatment diagnostic core biopsies and post-treatment surgical excisions were evaluated using a tunnel assay and immunohistochemistry staining with Ki-67 antibodies. A non-intervention retrospective control arm consisting of core and surgical tissue specimens from untreated patients was used to compare patients treated with B. Serrata. The change in proliferation and apoptosis between diagnostic core specimens and surgical specimens was compared between the control and treatment groups using a two-tailed paired t-test.

RESULTS

Twenty-two patients were enrolled, of which 20 received treatment, and 18 had sufficient tissue for IHC. There was an increase in percent change in proliferation from core biopsy to surgical excision in the control group (n = 18) of 54.6 ± 21.4%. In the B. serrata-treated group there was a reduction in proliferation between core biopsy and excision (n = 18) of 13.8 ± 11.7%. This difference was statistically significant between the control and B. serrata-treated groups (p = 0.008). There was no difference in change in apoptosis. There were no serious adverse events related to the drug.

CONCLUSION

Boswellia serrata inhibited breast cancer proliferation and was well-tolerated in a Phase Ia window of opportunity trial.

The journey of boswellic acids from synthesis to pharmacological activities

There has been a lot of interest in using naturally occurring substances to treat a wide variety of chronic disorders in recent years. From the gum resin of Boswellia serrata and Boswellia carteri, the pentacyclic triterpene molecules known as boswellic acid (BA) are extracted. We aimed to provide a detailed overview of the origins, chemistry, synthetic derivatives, pharmacokinetic, and biological activity of numerous Boswellia species and their derivatives. The literature searched for reports of B. serrata and isolated BAs having anti-cancer, anti-microbial, anti-inflammatory, anti-arthritic, hypolipidemic, immunomodulatory, anti-diabetic, hepatoprotective, anti-asthmatic, and clastogenic activities. Our results revealed that the cytotoxic and anticancer effects of B. serrata refer to its triterpenoid component, including BAs. Three-O-acetyl-11-keto-BA was the most promising cytotoxic molecule among tested substances. Activation of caspases, upregulation of Bax expression, downregulation of nuclear factor-kappa B (NF-kB), and stimulation of poly (ADP)-ribose polymerase (PARP) cleavage are the primary mechanisms responsible for cytotoxic and antitumor effects. Evidence suggests that BAs have shown promise in combating a wide range of debilitating disease conditions, including cancer, hepatic, inflammatory, and neurological disorders.

AKBA alleviates experimental pancreatitis by inhibiting oxidative stress in Macrophages through the Nrf2/HO-1 pathway

BACKGROUND

Acute pancreatitis (AP) is an inflammatory condition of the pancreas characterized by oxidative stress and inflammation in its pathophysiology. Acetyl-11-keto-β-boswellic acid (AKBA) is an active triterpenoid with antioxidant activity. This article seeks to assess the impact of AKBA on AP and investigate its underlying mechanisms.

METHODS

AP was induced in wild-type, Lyz2+/cre Nrf2fl/fl mice and Pdx1+/cre Nrf2fl/fl mice by caerulein. Serum amylase and lipase levels, along with histological grading, were utilized to evaluate the severity of AP. Murine bone marrow-derived macrophages (BMDMs) were isolated, cultured, and polarized to the M1 subtype. Flow cytometry and ELISA were utilized to identify the macrophage phenotype. Alterations in oxidative stress damage and intracellular ROS were observed. Nrf2/HO-1 signaling pathways were also evaluated.

RESULTS

In a caerulein-induced mouse model of AP, treatment with AKBA reduced blood amylase and lipase activity and ameliorated pancreatic tissue histological and pathological features. Furthermore, AKBA significantly mitigated oxidative stress-induced damage and induced the expression of Nrf2 and HO-1 protein. Additionally, by using conditional knockout mice (Lyz2+/cre Nrf2fl/fl and Pdx1+/cre Nrf2fl/fl mice), we verified that Nrf2 primarily functions in macrophages rather than acinar cells. In vitro, AKBA inhibits pro-inflammatory M1-subtype macrophage polarization and reduces ROS generation through Nrf2/HO-1 oxidative stress pathway. Moreover, the protective effects of AKBA against AP were abolished in myeloid-specific Nrf2-deficient mice and BMDMs. Molecular docking results revealed interactions between AKBA and Nrf2.

CONCLUSION

Our results confirm that AKBA exerts protective effects against AP in mice by inhibiting oxidative stress in macrophages through the Nrf2/HO-1 Pathway.

Anti-cancer effect of nano-encapsulated boswellic acids, curcumin and naringenin against HepG-2 cell line

BACKGROUND

liver cancer is one of the most common cancers in the world. So far, there is no gold standard treatment for hepatocellular carcinoma. We conducted this in vitro study to assess the effect of three natural products: Boswellic acids, curcumin and naringin versus corresponding nanoparticles (NPs) on Hep G2 cells proliferation.

METHODS

Boswellic acid, curcumin, naringin-loaded NPs were prepared using nanoprecipitation method. Human liver (HepG2) cell line was cultured in Dulbecco's modified Eagle's medium (DMEM). The cell growth inhibition and cytotoxicity were evaluated by MTT assay.

RESULTS

Boswellic acid, curcumin, naringin were able to inhibit HepG2 cells proliferation. IC50 at 24 h, 48 h showed significant lower values in NPs versus Free herbs. IC50 values of free Boswellic acids and NPs at 24 h were (24.60 ± 1.89 and 7.78 ± 0.54, P < 0.001), at 48 h were (22.45 ± 1.13 and 5.58 ± 0.27, P < 0.001) respectively. IC50 values of free curcumin and NPs at 24 h were (5.89 ± 0.8 and 3.46 ± 0.23, P < 0.05), at 48 h were (5.57 ± 0.94 and 2.51 ± 0.11, P < 0.05), respectively. For free and naringenin NPs, IC50 values at 24 h were (14.57 ± 1.78 and 7.25 ± 0.17, P < 0.01), at 48 h were (11.37 ± 1.45 and 5.21 ± 0.18, P < 0.01) respectively.

CONCLUSION

Boswellic acid, curcumin, naringin and their nanoprecipitation prepared nanoparticles suppressed Hep G2 cells proliferation.

Comparative study of the cytotoxicity, apoptotic, and epigenetic effects of Boswellic acid derivatives on breast cancer

This study aimed to compare the effect of Boswellic acid derivatives on the viability, apoptosis, and epigenomic profiling of breast cancer. According to the viability assays, 3-O-acetyl-11-keto-β-Boswellic acid (AKBA) showed more toxicity against MDA-MB-231 cells when compared with the 3-O-acetyl-β-Boswellic acid (ABA). In contrast, ABA revealed less toxicity against MCF-10A. Cell cycle and apoptosis assays determined the maximum apoptotic effect of AKBA on MCF-7, and MDA-MB-231 cells. Interestingly, β-Boswellic acid (BA) and ABA did not promote the apoptosis in MCF-10A cells. Transwell migration assay indicated the greatest normalized inhibition (around 160%) in the migration of MDA-MB-231 cells induced by AKBA. The expression of P53, BAX, and BCL2 genes in cancerous cell lines has affirmed that both AKBA and ABA could induce the maximal apoptosis. Western-blot investigation demonstrated that the maximum over-expression of P53 protein (1.96 times) was caused by AKBA in MDA-MB-231 cells, followed by ABA in MCF-7 cells. The BCL2 protein expression was in agreement with the previously reported results. The global DNA methylation in both cancerous cells was reduced by ABA. These results suggest that ABA represented more epigenetic modulatory effect while AKBA shows more cytotoxic and apoptotic effect against breast cancer cell lines.

3-O-Acetyl-11-keto-β-boswellic acid ameliorates acquired, consolidated and recognitive memory deficits through the regulation of hippocampal PPAR γ, MMP9 and MMP2 genes in dementia model

Pentacyclic Phytomolecule 3-O-Acetyl-11-keto-β-boswellic acid (AKBA) from Frankincense family has proven for the neuroprotection and recognized as an orphan drug for the treatment of cerebral edema. Nonetheless, AKBA have promising indications with Peroxisome proliferator activated receptor gamma (PPARγ) associated to cognitive function not deliberated so far. In order to substantiate the potential role of AKBA on memory function, we examine the contribution of PPARγ activation and its downstream process. Modified method of scopolamine induced dementia rats were treated with AKBA (5, 10&15 mg/kg,i.p) and Donepezil (2.5 mg/kg,i.p). Scopolamine induced short term spatial, working memory and recognition memory impairment was reversed significantly after AKBA treatment. AKBA administration diminished the Acetylcholine esterase (AchE) activity and preserved brain GABA and glutamate mediated neuronal excitability. Further, gene expression study reveals AKBA ameliorates the memory impairment via activating PPARγ and its downstream regulators, matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) genes in hippocampus. This study concludes that the treatment with AKBA can be a novel Phyto-molecule of interest for treating dementia via up-regulating hippocampus genes mediated cholinergic activation.

3-O-Acetyl-11-keto-β-boswellic acid ameliorates chronic unpredictable mild stress induced HPA axis dysregulation in relation with glutamate/GABA aberration in depressive rats

Overt expression of brain glucocorticoid receptor (GR) leads to elevation of glutamate release causes cerebral excitotoxicity which in turn produce neuropsychological disorders. The aim of our work is to study the consequence of 3-O-Acetyl-11-keto-β-boswellic acid (AKBA) on chronic unpredictable mild stress (CUMS) induced HPA axis dysregulation in relative to glutamate and GABA irregularity in depressive rats. AKBA (5, 10 &15mg/kg) was administered for 28 days parallel with CUMS induction in rats. Behavioural studies, tail suspension test (TST), open field exploratory (OFT) and forced swim test (FST) were performed. Biochemical studies including plasma corticosterone, glutamate GABA and glutamic acid decarboxylase (GAD) enzyme activity were studied. Glucocorticoid receptor expression and brain histology were studied to observe the effect of AKBA. CUMS induction results in depressive state of the animals were confirmed by the sucrose preference test. The administration of AKBA significantly reduced the immobility time and improved the exploratory behaviour. Plasma corticosterone and brain glutamate level was decreased and GABA level were increased significantly evident with GAD activation in AKBA-treated animals, further confirmed with decreased GR expression improves architecture of prefrontal cortex region. Correlation study illustrates behavioural improvements undeviating the biochemical alteration and GR expression after AKBA treatment during depression. AKBA significantly reversed the CUMS-induced glutamate/GABA abnormalities through the adaptation of central HPA axis regulation. Hence this study concludes that AKBA can be a better alternative to treat depressive disorders.

Potential therapeutic effects of boswellic acids/Boswellia serrata extract in the prevention and therapy of type 2 diabetes and Alzheimer's disease

The link between diabetes and cognitive dysfunction has been reported in many recent articles. There is currently no disease-modifying treatment available for cognitive impairment. Boswellia serrata (B. serrata) is used traditionally to treat chronic inflammatory diseases such as type 2 diabetes (T2D), insulin resistance (IR), and Alzheimer's disease (AD). This review aims to highlight current research on the potential use of boswellic acids (BAs)/B. serrata extract in T2D and AD. We reviewed the published information through June 2021. Studies have been collected through a search on online electronic databases (Academic libraries as PubMed, Scopus, Web of Science, and Egyptian Knowledge Bank). Accumulating evidence in preclinical and small human clinical studies has indicated that BAs/B. serrata extract has potential therapeutic effect in T2D and AD. According to most of the authors, the potential therapeutic effects of BAs/B. serrata extract in T2D and AD can be attributed to immunomodulatory, anti-inflammatory, antioxidant activity, and elimination of the senescent cells. BAs/B. serrata extract may act by inhibiting the IκB kinase/nuclear transcription factor-κB (IKK/NF-κB) signaling pathway and increasing the formation of selective anti-inflammatory LOX-isoform modulators. In conclusion, BAs/B. serrata extract may have positive therapeutic effects in prevention and therapy of T2D and AD. However, more randomized controlled trials with effective, large populations are needed to show a definitive conclusion about therapeutic efficacy of BAs/B. serrata extract in T2D and AD.

Evaluation of the solubility of 11-keto-β-boswellic acid and its histological effect on the diabetic mice liver using a novel technique

Background and Aim:

The literature is scant on the effect of 11-keto-β-boswellic acid (KBA) on the liver of diabetes-induced mice. This study was designed to develop a rapid, sensitive, accurate, and inexpensive detection technique for evaluating the solubility of KBA obtained from the gum resin of Omani frankincense (Boswellia sacra) in the liver of streptozotocin-induced diabetic mice using Fourier transform infrared (FTIR) reflectance spectroscopy coupled with principal components analysis (PCA). It also aimed to investigate the effect of KBA on histological changes in the hepatocytes of diabetic mice.

Materials and Methods:

Eighteen mice were assigned to the healthy control group, the diabetic control group, or the KBA-treated diabetic group. Liver tissue samples from all groups were scanned using an FTIR reflectance spectrophotometer in reflection mode. FTIR reflectance spectra were collected in the wavenumber range of 400-4000 cm⁻¹ using an attenuated total reflectance apparatus.

Results:

FTIR reflectance spectra were analyzed using PCA. The PCA score plot, which is an exploratory multivariate data set, revealed complete segregation among the three groups’ liver samples based on changes in the variation of wavenumber position in the FTIR reflectance spectra, which indicated a clear effect of KBA solubility on treatments. Histological analysis showed an improvement in the liver tissues, with normal structures of hepatocytes exhibiting mild vacuolation in their cytoplasm.

Conclusion:

KBA improved the morphology of liver tissues in the diabetic mice and led to complete recovery of the damage observed in the diabetic control group. FTIR reflectance spectroscopy coupled with PCA could be deployed as a rapid, low-cost, and non-destructive detection method for evaluating treatment effects in diseased liver tissue based on the solubility of KBA.

Inhibition of SARS-CoV-2 reproduction using Boswellia carterii: A theoretical study

This study investigated the possibility of inhibition of the SARS-CoV-2 virus using the compounds alpha-Boswellic acid (ABA) and beta-Boswellic acid (BBA) which are active components in the well-known natural product Boswellia carterii (BC). The SARS-CoV-2 virus reproduces in the body by linking its spike with the cell receptor. At the same time, a pH range (4.5-6) of the cell's lysosomes is considered as a perfect environment to release RNA in the cell cytoplasm. In view of these, docking studies were employed to study the interaction between the spikes of the virus and ABA or BBA using Molecular Graphic Laboratory (MGL) tools and AutoDock Vina application. The binding of the ABA and BBA with the spike of the virus could inhibit its reproduction or provide sufficient time for the immune system to recognize the virus and hence, produce suitable antibodies. In addition, the pKa of ABA, BBA and hydroxychloroquine (HCQ) were calculated using HF/6-311G (d,p) method and then they were compared with the experimental pKa of HCQ. The Lethal Concentrations (LC50) of ABA and BBA were also calculated. In addition, molecular electrostatic potential is reported which indicates the active sites of ABA and BBA.

Considerations to Be Taken When Carrying Out Medicinal Plant Research-What We Learn from an Insight into the IC50 Values, Bioavailability and Clinical Efficacy of Exemplary Anti-Inflammatory Herbal Components

Medicinal plants represent a big reservoir for discovering new drugs against all kinds of diseases including inflammation. In spite the large number of promising anti-inflammatory plant extracts and isolated components, research on medicinal plants proves to be very difficult. Based on that background this review aims to provide a summarized insight into the hitherto known pharmacologically active concentrations, bioavailability, and clinical efficacy of boswellic acids, curcumin, quercetin and resveratrol. These examples have in common that the achieved plasma concentrations were found to be often far below the determined IC50 values in vitro. On the other hand demonstrated therapeutic effects suggest a necessity of rethinking our pharmacokinetic understanding. In this light this review discusses the value of plasma levels as pharmacokinetic surrogates in comparison to the more informative value of tissue concentrations. Furthermore the need for new methodological approaches is addressed like the application of combinatorial approaches for identifying and pharmacokinetic investigations of active multi-components. Also the physiological relevance of exemplary in vitro assays and absorption studies in cell-line based models is discussed. All these topics should be ideally considered to avoid inaccurate predictions for the efficacy of herbal components in vivo and to unlock the "black box" of herbal mixtures.

Pharmacokinetics of solid lipid Boswellia serrata particles in healthy subjects

OBJECTIVES

The anti-inflammatory activity of Boswellia serrata extracts (BSE) is well known. BSE comprises boswellic acids (BA) such as 3-O-acetyl-11-keto-beta-boswellic acid (AKBA) and 11-keto-boswellic acid (KBA) as major constituents. One of the limitations of BAs is their poor oral bioavailability. The aim of the study was to prepare solid lipid particles of Boswellia serrata extract (SLBSP) to enhance the bioavailability of BAs.

METHODS

The pharmacokinetic profile of BAs was studied in 10 healthy human volunteers following a single oral dose of 333 mg of SLBSP. Pharmacokinetic blood samples were collected at 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, and 12 h post drug administration. Plasma KBA and AKBA levels were measured using a validated LC-MS/MS method. Pharmacokinetics parameters were estimated using Pheonix WinNonlin (Build 6.4.0.768) software.

RESULTS

Ten healthy human volunteers were included and peak plasma concentration was achieved in 1.5 and 2.3 h for AKBA and KBA respectively. Maximum plasma concentration (C max) was 8.04 ± 1.67 ng/mL for AKBA and 23.83 ± 4.41 ng/mL for KBA whereas the corresponding area under the concentration-time curve (AUC) was 136.7 ± 56.77 ng/mL*h and 165.7 ± 24.5 ng/mL*h respectively. The elimination half-life (t 1/2) of AKBA and KBA was 6.8 ± 3.0 h and 2.45 ± 0.3 h respectively.

CONCLUSIONS

The SLBSP formulation of BSE showed enhanced oral bioavailability of BAs compared with historically reported data of unformulated BSE.

Pharmacokinetics of solid lipid Boswellia serrata particles in healthy subjects

OBJECTIVES

The anti-inflammatory activity of Boswellia serrata extracts (BSE) is well known. BSE comprises boswellic acids (BA) such as 3-O-acetyl-11-keto-beta-boswellic acid (AKBA) and 11-keto-boswellic acid (KBA) as major constituents. One of the limitations of BAs is their poor oral bioavailability. The aim of the study was to prepare solid lipid particles of Boswellia serrata extract (SLBSP) to enhance the bioavailability of BAs.

METHODS

The pharmacokinetic profile of BAs was studied in 10 healthy human volunteers following a single oral dose of 333 mg of SLBSP. Pharmacokinetic blood samples were collected at 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, and 12 h post drug administration. Plasma KBA and AKBA levels were measured using a validated LC-MS/MS method. Pharmacokinetics parameters were estimated using Pheonix WinNonlin (Build 6.4.0.768) software.

RESULTS

Ten healthy human volunteers were included and peak plasma concentration was achieved in 1.5 and 2.3 h for AKBA and KBA respectively. Maximum plasma concentration (C _max) was 8.04 ± 1.67 ng/mL for AKBA and 23.83 ± 4.41 ng/mL for KBA whereas the corresponding area under the concentration-time curve (AUC) was 136.7 ± 56.77 ng/mL*h and 165.7 ± 24.5 ng/mL*h respectively. The elimination half-life (t _1/2) of AKBA and KBA was 6.8 ± 3.0 h and 2.45 ± 0.3 h respectively.

CONCLUSIONS

The SLBSP formulation of BSE showed enhanced oral bioavailability of BAs compared with historically reported data of unformulated BSE.

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.

Plant-Derived Natural Products in Cancer Research: Extraction, Mechanism of Action, and Drug Formulation

Cancer is one of the main causes of death globally and considered as a major challenge for the public health system. The high toxicity and the lack of selectivity of conventional anticancer therapies make the search for alternative treatments a priority. In this review, we describe the main plant-derived natural products used as anticancer agents. Natural sources, extraction methods, anticancer mechanisms, clinical studies, and pharmaceutical formulation are discussed in this review. Studies covered by this review should provide a solid foundation for researchers and physicians to enhance basic and clinical research on developing alternative anticancer therapies.

Modulation of Lipid Transport and Adipose Tissue Deposition by Small Lipophilic Compounds

Small lipophilic molecules present in foods of plant origin have relevant biological activities at rather low concentrations. Evidence suggests that phytosterols, carotenoids, terpenoids, and tocopherols can interact with different metabolic pathways, exerting beneficial effects against a number of metabolic diseases. These small molecules can modulate triacylglycerol absorption in the intestine and the biosynthesis of chylomicrons, the lipid carriers in the blood. Once in the bloodstream, they can impact lipoprotein clearance from blood, thereby affecting fatty acid release, incorporation into adipocytes and triglyceride reassembling and deposit. Consequently, some of these molecules can regulate pathophysiological processes associated to obesity and its related conditions, such as insulin resistance, metabolic syndrome and type-2 diabetes. The protective capacity of some lipophilic small molecules on oxidative and chemotoxic stress, can modify the expression of key genes in the adaptive cellular response, such as transcription factors, contributing to prevent the inflammatory status of adipose tissue. These small lipophilic compounds can be incorporated into diet as natural parts of food but they can also be employed to supplement other dietary and pharmacologic products as nutraceuticals, exerting protective effects against the development of metabolic diseases in which inflammation is involved. The aim of this review is to summarize the current knowledge of the influence of dietary lipophilic small biomolecules (phytosterols, carotenoids, tocopherols, and triterpenes) on lipid transport, as well as on the effects they may have on pathophysiological metabolic states, related to obesity, insulin resistance and inflammation, providing an evidence-based summary of their main beneficial effects on human health.

Development and characterization of bacterial nanocellulose loaded with Boswellia serrata extract containing nanoemulsions as natural dressing for skin diseases

The combination of the anti-inflammatory lipophilic Boswellia serrata extract with the natural hydropolymer bacterial nanocellulose (BNC) for the treatment of skin diseases is counteracted by their different hydro/lipophilicity. To overcome the hydrophilicity of the BNC, the water in its network was exchanged by single and double nanoemulsions. Incorporation of the Boswellia serrata extract in the nanoemulsions formed particles of about 115 to 150 nm with negative zeta potential and storage stability over 30 days at temperatures between 4 and 32 °C. Their loading into the BNC did not change the preferential characteristics of the nanocellulose like water absorption and retention, softness, and pressure stability in a relevant way. Loaded BNC could be sterilized by an electron-beam procedure. A biphasic drug release profile of lead compounds was observed by Franz cell diffusion test. The biocompatibility of the loaded BNC was confirmed ex ovo by a shell-less hen's egg test. Tape stripping experiments using porcine skin determined a dependency of the drug penetration into skin on the type of nanoemulsion, single vs. repeated applications and the incubation time. In conclusion, the hydrophilicity of BNC could be overcome using nanoemulsions which offers the possibility for the anti-inflammatory skin treatment with Boswellia serrata extract.

Biological Activity of Some Aromatic Plants and Their Metabolites, with an Emphasis on Health-Promoting Properties

The biological activities of four aromatic plants, namely frankincense, myrrh, ginger, and turmeric, were reviewed in the current study. The volatile fraction (essential oil) as well as the nonvolatile fraction of these four plants showed different promising biological activities that are displayed in detail. These activities can include protection from and/or alleviation of some ailment, which is supported with different proposed mechanisms of action. This review aimed to finally help researchers to get a handle on the importance of considering these selected aromatic plants, which have not been thoroughly reviewed before, as a potential adjuvant to classical synthetic drugs to enhance their efficiency. Moreover, the results elicited in this review encourage the consumption of these medicinal plants as an integrated part of the diet to boost the body's overall health based on scientific evidence.

Acetyl-11-keto-β-boswellic acid ameliorates cognitive deficits and reduces amyloid-β levels in APPswe/PS1dE9 mice through antioxidant and anti-inflammatory pathways

Alzheimer's disease (AD) is a complex disease involved oxidative stress and inflammation in its pathogenesis. Acetyl-11-keto-β-boswellic acid (AKBA) is an active triterpenoid compound from extracts of Boswellia serrata, which has been widely used as an antioxidant and anti-inflammatory agent. The present study was to determine whether AKBA, a novel candidate, could protect against cognitive and neuropathological impairments in AD. We found that AKBA treatment resulted in a significant improvement of learning and memory deficits, a dramatic decrease in cerebral amyloid-β (Aβ) levels and plaque burden, a profound alleviation in oxidative stress and inflammation, and a marked reduction in activated glial cells and synaptic defects in the APPswe/PS1dE9 mice. Furthermore, amyloid precursor protein (APP) processing was remarkably suppressed with AKBA treatment by inhibiting beta-site APP cleaving enzyme 1 (BACE1) protein expression to produce Aβ in the APPswe/PS1dE9 mice brains. Mechanistically, AKBA modulated antioxidant and anti-inflammatory pathways via increasing nuclear erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression, and via declining phosphorylation of inhibitor of nuclear factor-kappa B alpha (IκBα) and p65. Collectively, our findings provide evidence that AKBA protects neurons against oxidative stress and inflammation in AD, and this neuroprotective effect involves the Nrf2/HO-1 and nuclear factor-kappa B (NF-κB) signaling pathways.

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.

Ex-vivo intestinal absorption study of boswellic acid, cyclodextrin complexes and poloxamer solid dispersions using everted gut sac technique

Acetyl- Keto-β-boswellic acid (AKBA) is a pentacyclic triterpenic acid found in gum resin of Boswellia serrata. Even though it is shown to have anti-inflammatory activity, its bioavailability gets limited due to its poor aqueous solubility and permeability. The present study, hence, deals in enhancement of the intestinal absorption of AKBA from total boswellic acid fraction (TA fraction) using cyclodextrin (CD) and poloxamer solid dispersion (PXM SDs) formulations. Absorption studies were performed using the everted gut sac model prepared from rat jejunum. The glucose uptake assay was performed to show viability of gut sac tissue. The apparent permeability (P_app) value of AKBA from TA fraction was 1.08 ± 0.17 × 10^-6 which was found to be increased by 10-14 fold with CD complex and SD formulations. The intestinal absorption studies showed highest absorption of AKBA from HP-β-CD complex and PXM 407 SD as compared to that from TA fraction. From this study, it can be concluded that HP-β-CD and PXM 407 effectively enhanced intestinal absorption through improved solubility, highlighting their role as efficient drug delivery agents and bioavailability enhancers.

Simultaneous HPTLC Densitometric Estimation of KBA and AKBA from Boswellia serrata

Background:

Boswellic acids (BAs) are extracted from oleo gum of Boswellia serrata and are utilized as potential anti-inflammatory, hypolipidemic, immunomodulatory and antitumor specialists. The present examination was meant to assess KBA and AKBA in Boswellia serrata separate by High-Performance Thin Layer Chromatography (HPTLC).

Methods:

The separation of bioactive compounds was performed utilizing mobile phase glacial acetic acid, n-hexane, ethyl acetate and toluene (0.3: 1: 8: 2) (v/v/v/v) and distinguished at wavelength 254 nm. The technique was approved for linearity, precision, accuracy, limit of detection (LOD), limit of quantification (LOQ), and so forth by International Conference on Harmonization guidelines.

Results:

The calibration range was observed to be 2- 14 μg/band for both the bioactive compounds. KBA was isolated with an Rf estimation of 0.39 ± 0.02 and AKBA with an Rf estimation of 0.42 ± 0.02. The accuracy was seen to be as high as 99.17% and 97.42 for KBA and KBA, respectively. The percentage RSD value for intra-day and between day varieties was under 2%. The system indicated high affectability and specificity.

Conclusion:

The developed HPTLC method was simple, precise, robust, specific, rapid, and costeffective and could be used for quality control analysis and quantification of KBA and AKBA in different herbal formulations containing the plant species.

Which supplements can I recommend to my osteoarthritis patients?

OA is a chronic and disabling joint disease with limited evidence-based pharmacological treatment options available that improve outcomes for patients safely. Faced with few effective pharmacological treatments, the use has grown of dietary supplements and complementary medicines for symptomatic relief among people living with OA. The aim of this review is to provide a summary of existing evidence and recommendations supporting the use of supplements for OA. Systematic reviews and randomized controlled trials investigating oral supplements for treating OA were identified. Limited research evidence supports recommendations for the oral use of Boswellia serrata extract and Pycnogenol, curcumin and methylsulfonylmethane in people with OA despite the poor quality of the available studies. Few studies adequately reported possible adverse effects related to supplementation, although the products were generally recognized as safe. Further high quality trials are needed to improve the strength of evidence to support this recommendation and better guide optimal treatment of people living with OA.

Triterpene Acids from Frankincense and Semi-Synthetic Derivatives That Inhibit 5-Lipoxygenase and Cathepsin G

Age-related diseases, such as osteoarthritis, Alzheimer’s disease, diabetes, and cardiovascular disease, are often associated with chronic unresolved inflammation. Neutrophils play central roles in this process by releasing tissue-degenerative proteases, such as cathepsin G, as well as pro-inflammatory leukotrienes produced by the 5-lipoxygenase (5-LO) pathway. Boswellic acids (BAs) are pentacyclic triterpene acids contained in the gum resin of the anti-inflammatory remedy frankincense that target cathepsin G and 5-LO in neutrophils, and might thus represent suitable leads for intervention with age-associated diseases that have a chronic inflammatory component. Here, we investigated whether, in addition to BAs, other triterpene acids from frankincense interfere with 5-LO and cathepsin G. We provide a comprehensive analysis of 17 natural tetra- or pentacyclic triterpene acids for suppression of 5-LO product synthesis in human neutrophils. These triterpene acids were also investigated for their direct interference with 5-LO and cathepsin G in cell-free assays. Furthermore, our studies were expanded to 10 semi-synthetic BA derivatives. Our data reveal that besides BAs, several tetra- and pentacyclic triterpene acids are effective or even superior inhibitors of 5-LO product formation in human neutrophils, and in parallel, inhibit cathepsin G. Their beneficial target profile may qualify triterpene acids as anti-inflammatory natural products and pharmacological leads for intervention with diseases related to aging.

Bioavailability of Terpenes and Postprandial Effect on Human Antioxidant Potential. An Open-Label Study in Healthy Subjects

SCOPE

To assess bioavailability of terpenes in human plasma and their effect on oxidative stress biomarkers.

METHODS AND RESULTS

In this open-label and single arm postprandial trial, seventeen healthy male volunteers (20-40 years old) follow a low-phytochemical diet for 5 days. Next, after overnight fasting, volunteers consume Mastiha powder (a natural resin rich in terpenes) dispersed in water. Blood samples are collected on time points 0 h (before ingestion) and 0.5, 1, 2, 4, 6, and 24 h (post-ingestion). Ultra-high-pressure liquid chromatography high-resolution MS (UHPLC-HRMS/MS) is applied for high throughput analysis of plasma. Serum resistance to oxidation and oxidized LDL (oxLDL) levels are measured. UHPLC-HRMS/MS analysis shows that major terpenes are bioavailable since 0.5 h after administration, reaching a peak between 2 h and 4 h. Serum resistance to oxidation, expressed as difference of tLAG (time point-0 h), starts to increase from 0.5 h. This increase reaches statistical significance at 4 h (402.3 ± 65.0 s), peaks at 6 h (524.6 ± 62.9 s), and remains statistically significant until 24 h (424.2 ± 48.0 s). oxLDL levels, expressed as %change from 0 h, are reduced significantly from time point-1 h until time point-6 h.

CONCLUSION

Results demonstrate the terpene bioavailability pattern after oral administration of Mastiha. Terpenes are potential mediators of antioxidant defense in vivo.

Pentacyclic Triterpene Bioavailability: An Overview of In Vitro and In Vivo Studies

Pentacyclic triterpenes are naturally found in a great variety of fruits, vegetables and medicinal plants and are therefore part of the human diet. The beneficial health effects of edible and medicinal plants have partly been associated with their triterpene content, but the in vivo efficacy in humans depends on many factors, including absorption and metabolism. This review presents an overview of in vitro and in vivo studies that were carried out to determine the bioavailability of pentacyclic triterpenes and highlights the efforts that have been performed to improve the dissolution properties and absorption of these compounds. As plant matrices play a critical role in triterpene bioaccessibility, this review covers literature data on the bioavailability of pentacyclic triterpenes ingested either from foods and medicinal plants or in their free form.

A single-dose, randomized, cross-over, two-way, open-label study for comparing the absorption of boswellic acids and its lecithin formulation

BACKGROUND

The oral administration of the gum resin extracts of Indian frankincense (Boswellia serrata Roxb. ex Colebr) results in very low plasma concentrations of boswellic acids (BAs), being far below the pharmacologically active concentrations required in vitro for anti-inflammatory activity. For that reason the use of Indian frankincense in clinical practice and pharmaceutical development has substantially lagged behind. Recently the application of new formulation technologies resulted in a formulation of frankincense extract with lecithin, which revealed improved absorption and tissue penetration of BAs in a rodent study, leading for the first time to plasma concentrations of BAs in the range of their anti-inflammatory activity.

PURPOSE

In order to verify these encouraging results in humans, the absorption of a standardized Boswellia serrata extract (BE) and its lecithin formulation (CSP) was comparatively investigated in healthy volunteers.

STUDY DESIGN

According to a randomized cross-over design with two treatments, two sequences and two periods, 12 volunteers alternatively received the lecithin-formulated Boswellia extract (CSP) or the non-formulated Boswellia extract (BE) at a dosage of 2×250mg capsules.

METHODS

The plasma concentrations of the six major BAs (KBA, AKBA, βBA, αBA, AβBA, AαBA) were determined using LC/MS.

RESULTS

With the exception of KBA, a significantly higher (both in terms of weight-to-weight and molar comparison) and quicker absorption of BAs from the lecithin formulation was observed, leading to C_max in the range required for the interaction with their molecular targets.

CONCLUSION

These findings pave the way to further studies evaluating the clinical potential of BAs, and verify the beneficial effect of lecithin formulation to improve the absorption of poorly soluble phytochemicals.

Boswellic acids target the human immune system-modulating antimicrobial peptide LL-37

The antimicrobial peptide LL-37 is the sole member of the human cathelicidin family with immune system-modulating properties and roles in autoimmune disease development. Small molecules able to interact with LL-37 and to modulate its functions have not been described yet. Boswellic acids (BAs) are pentacyclic triterpene acids that are bioactive principles of frankincense extracts used as anti-inflammatory remedies. Although various anti-inflammatory modes of action have been proposed for BAs, the pharmacological profile of these compounds is still incompletely understood. Here, we describe the identification of human LL-37 as functional target of BAs. In unbiased target fishing experiments using immobilized BAs as bait and human neutrophils as target source, LL-37 was identified as binding partner assisted by MALDI-TOF mass spectrometry. Thermal stability experiments using circular dichroism spectroscopy confirm direct interaction between BAs and LL-37. Of interest, this binding of BAs resulted in an inhibition of the functionality of LL-37. Thus, the LPS-neutralizing properties of isolated LL-37 were inhibited by 3-O-acetyl-β-BA (Aβ-BA) and 3-O-acetyl-11-keto-β-BA (AKβ-BA) in a cell-free limulus amoebocyte lysate assay with EC50=0.2 and 0.8 μM, respectively. Also, LL-37 activity was inhibited by these BAs in LL-37-enriched supernatants of stimulated neutrophils or human plasma derived from stimulated human whole blood. Together, we reveal BAs as inhibitors of LL-37, which might be a relevant mechanism underlying the anti-inflammatory properties of BAs and suggests BAs as suitable chemical tools or potential agents for intervention with LL-37 and related disorders.

Effect of phospholipid-based formulations of Boswellia serrata extract on the solubility, permeability, and absorption of the individual boswellic acid constituents present

Boswellia serrata gum resin extracts are used widely for the treatment of inflammatory diseases. However, very low concentrations in the plasma and brain were observed for the boswellic acids (1-6, the active constituents of B. serrata). The present study investigated the effect of phospholipids alone and in combination with common co-surfactants (e.g., Tween 80, vitamin E-TPGS, pluronic f127) on the solubility of 1-6 in physiologically relevant media and on the permeability in the Caco-2 cell model. Because of the high lipophilicity of 1-6, the permeability experiments were adapted to physiological conditions using modified fasted state simulated intestinal fluid as apical (donor) medium and 4% bovine serum albumin in the basolateral (receiver) compartment. A formulation composed of extract/phospholipid/pluronic f127 (1:1:1 w/w/w) increased the solubility of 1-6 up to 54 times compared with the nonformulated extract and exhibited the highest mass net flux in the permeability tests. The oral administration of this formulation to rats (240 mg/kg) resulted in 26 and 14 times higher plasma levels for 11-keto-β-boswellic acid (1) and acetyl-11-keto-β-boswellic acid (2), respectively. In the brain, five times higher levels for 2 compared to the nonformulated extract were determined 8 h after oral administration.

In vitro metabolism, permeation, and brain availability of six major boswellic acids from Boswellia serrata gum resins

Boswellia serrata gum resin extracts (BSE) revealed potent anti-inflammatory actions in preclinical and clinical studies. In 2002 BSE was assigned an orphan drug status by the European Medicines Agency (EMA) for the treatment of peritumoral edema. In the past pharmacological effects of BSE were mainly attributed to 11-keto-β-boswellic acid (KBA) and 3-acetyl-11-keto-β-boswellic acid (AKBA). Therefore pharmacokinetic and pharmacodynamic studies focused mainly on these two boswellic acids (BAs). However, other BAs, like β-boswellic acid (βBA), might also contribute to the anti-inflammatory actions of BSE. Here, we determined the metabolic stability, permeability and brain availability of six major BAs, that is, KBA, AKBA, βBA, 3-acetyl-β-boswellic acid (AβBA), α-boswellic acid (αBA), and 3-acetyl-α-boswellic acid (AαBA). For permeability studies, the Caco-2 model was adapted to physiological conditions by the addition of bovine serum albumin (BSA) to the basolateral side and the use of modified fasted state simulated intestinal fluid (FaSSIF) on the apical side. Under these conditions the four BAs lacking the 11-keto moiety revealed moderate permeability. Furthermore the permeability of AKBA and KBA was improved compared to earlier studies. In contrast to Aα- and AβBA, βBA and αBA were intensively metabolized after incubation with human and rat liver microsomes. Finally, the availability of all six major BAs could be confirmed in rat brain 8h after oral administration of 240mg/kg BSE to rats showing mean concentrations of 11.6ng/g for KBA, 37.5ng/g for AKBA, 485.1ng/g for αBA, 1066.6ng/g for βBA, 43.0ng/g for AαBA and 163.7ng/g for AβBA.

Enhanced absorption of boswellic acids by a lecithin delivery form (Phytosome(®)) of Boswellia extract

The anti-inflammatory potential of Boswellia serrata gum resin extracts has been demonstrated in vitro and in animal studies as well as in pilot clinical trials. However, pharmacokinetic studies have evidenced low systemic absorption of boswellic acids (BAs), especially of KBA and AKBA, in rodents and humans. This observation has provided a rationale to improve the formulation of Boswellia extract. We present here the results of a murine comparative bioavailability study of Casperome™, a soy lecithin formulation of standardized B. serrata gum resin extract (BE), and its corresponding non-formulated extract. The concentration of the six major BAs [11-keto-β-boswellic acid (KBA), acetyl-11-keto-β-boswellic acid (AKBA), β-boswellic acid (βBA), acetyl-β-boswellic acid (AβBA), α-boswellic acid (αBA), and acetyl-α-boswellic acid (AαBA)] was evaluated in the plasma and in a series of tissues (brain, muscle, eye, liver and kidney), providing the first data on tissue distribution of BAs. Weight equivalent and equimolar oral administration of Casperome™ provided significantly higher plasma levels (up to 7-fold for KBA, and 3-fold for βBA quantified as area under the plasma concentration time curve, AUC(last)) compared to the non-formulated extract. This was accompanied by remarkably higher tissue levels. Of particular relevance was the marked increase in brain concentration of KBA and AKBA (35-fold) as well as βBA (3-fold) following Casperome™ administration. Notably, up to 17 times higher BA levels were observed in poorly vascularized organs such as the eye. The increased systemic availability of BAs and the improved tissue distribution, qualify Casperome™ for further clinical development to fully exploit the clinical potential of BE.