Remodeling of Actin Cytoskeleton in Lupeol-Induced B16 2F2 Cell Differentiation

Lupeol: A dietary and medicinal triterpene with therapeutic potential

Lupeol, a triterpene derived from various plants, has emerged as a potent dietary supplement with extensive therapeutic potential. This review offers a comprehensive examination of lupeol's applications across diverse health conditions. By meticulously analyzing current scientific literature, we have synthesized findings that underscore lupeol's impact on cancer, diabetes, gastrointestinal disorders, neurological diseases, dermatological conditions, nephrological issues, and cardiovascular health. The review delves into molecular studies that reveal lupeol's ability to modulate disease pathways and alleviate symptoms, positioning it as a promising therapeutic agent. Moreover, we discuss the potential role of lupeol in clinical practice and public health strategies, emphasizing its substantial benefits as a natural compound. This thorough analysis serves as a critical resource for researchers, providing insights into the multifaceted therapeutic properties of lupeol and its potential to significantly enhance health outcomes.

Progress in Antimelanoma Research of Natural Triterpenoids and Their Derivatives: Mechanisms of Action, Bioavailability Enhancement and Structure Modifications

Melanoma is one of the most dangerous forms of skin cancer, characterized by early metastasis and rapid development. In search for effective treatment options, much attention is given to triterpenoids of plant origin, which are considered promising drug candidates due to their well described anticancer properties and relatively low toxicity. This paper comprehensively summarizes the antimelanoma potential of natural triterpenoids, that are also used as scaffolds for the development of more effective derivatives. These include betulin, betulinic acid, ursolic acid, maslinic acid, oleanolic acid, celastrol and lupeol. Some lesser-known triterpenoids that deserve attention in this context are 22β-hydroxytingenone, cucurbitacins, geoditin A and ganoderic acids. Recently described mechanisms of action are presented, together with the results of preclinical in vitro and in vivo studies, as well as the use of drug delivery systems and pharmaceutical technologies to improve the bioavailability of triterpenoids. This paper also reviews the most promising structural modifications, based on structure-activity observations. In conclusion, triterpenoids of plant origin and some of their semi-synthetic derivatives exert significant cytotoxic, antiproliferative and chemopreventive effects that can be beneficial for melanoma treatment. Recent data indicate that their poor solubility in water, and thus low bioavailability, can be overcome by complexing with cyclodextrins, or the use of nanoparticles and ethosomes, thus making these compounds promising antimelanoma drug candidates for further development.

A clickable photoaffinity probe of betulinic acid identifies tropomyosin as a target

Target identification of bioactive compounds is important for understanding their mechanisms of action and provides critical insights into their therapeutic utility. While it remains a challenge, unbiased chemoproteomics strategy using clickable photoaffinity probes is a useful and validated approach for target identification. One major limitation of this approach is the efficient synthesis of appropriately substituted clickable photoaffinity probes. Herein, we describe an efficient and consistent method to prepare such probes. We further employed this method to prepare a highly stereo-congested probe based on naturally occurring triterpenoid betulinic acid. With this photoaffinity probe, we identified tropomyosin as a novel target for betulinic acid that can account for the unique biological phenotype on cellular cytoskeleton induced by betulinic acid.

Sulforaphane induces cell differentiation, melanogenesis and also inhibit the proliferation of melanoma cells

Sulforaphane (SFN) is an organosulfur compound extracted from cruciferous vegetables and has biological effects. The effect of SFN has been studied in different types of cancers, as this compound incites various cytotoxic mechanisms to stunt cancer proliferation. However, the role of SFN activity in melanoma is yet to be known. The current study has been devised to elucidate the effects induced by SFN treatment in the B16F10 melanoma cell line and zebrafish model. Cells were treated with SFN reduced cell proliferation and increased tyrosinase production. Moreover, microscopic and immunofluorescence analysis confirmed the elongated appearance of melanoma cells due to cytoskeletal reorganization induced by SFN. Western blotting showed that SFN regulates the protein expression of Microphthalmia-associated transcription factor (MITF), Protein kinase C beta 1 (PKCβ1), and tyrosinase. The relationship between melanin biosynthesis and changes in the actin cytoskeleton encouraged by SFN on melanoma was determined by treating it with Cytochalasin D (CD) and Jasplakinolide (JAS). Co-treatment of SFN with CD increased more tyrosinase expression than SFN alone whereas with JAS, slightly reduced the expression. Immature zebrafish were pretreated with phenylthiourea (PTU) and then exposed to different SFN concentrations yielded the same results by upregulating the melanin levels despite the presence of melanin inhibitor (PTU). These study results show that SFN induces the biosynthesis of melanin in the B16F10 melanoma cell line, which occurs through changes in actin.

Lupeol inhibits migration and invasion of colorectal cancer cells by suppressing RhoA-ROCK1 signaling pathway

Metastasis is the main cause of death in colorectal cancer (CRC) patients. However, current treatment options for CRC metastasis are very limited. Lupeol, a triterpene that is widely found in vegetables and fruits, has been reported to possess the cancer-preventive and anti-inflammatory functions. However, the roles of Lupeol in the migration and invasion of colorectal cancer remain unclear. Here, we evaluated the effect of Lupeol treatment on colorectal cancer cell lines, HCT116 and SW620, and delineated its underlying mechanisms. Our results showed that Lupeol induced a dose-dependent inhibition of HCT116 and SW620 cells viability, measured by CCK8 assay. Wound healing and Transwell migration and invasion assays revealed that Lupeol significantly suppressed the migration and invasion of CRC cells. Using laser confocal microscope, we observed that the pseudopods and protrusions of HCT116 and SW620 cells decreased and disrupted after treatment with Lupeol. In addition, the quantitative real-time PCR and Western blotting results showed that Lupeol downregulated the expression of RhoA and RhoC, and their downstream effectors ROCK1, Cofilin, p-MLC, and the associated regulatory protein Cyclin A2. Interestingly, the migration and invasion capacity of CRC cells was reduced after RhoA knockdown. And there were no additional changes in CRC cells with RhoA knockdown to treat with Lupeol. These findings demonstrate that Lupeol can suppress the migration and invasion of colorectal cancer cells by remodeling the actin cytoskeleton via RhoA-ROCK1 pathway inhibition, which may provide an effective anti-metastatic agent for CRC patients.

Reversing effect of Lupeol on vasculogenic mimicry in murine melanoma progression

Vasculogenic mimicry, an endothelia-independent tumor microcirculation has been found in various cancers and is thought to be achieved by cancer stem like cells. Dacarbazine resistance is one of the most common features of melanoma and recent studies suggest that the mode of resistance is closely related to the formation of vasculogenic mimicry. In our work, we examined the anticancer effect of Lupeol, a novel phytochemical with Dacarbazine in vivo and in vitro. Results demonstrated adequate cytotoxicity followed by down regulation of CD 133 expression in Lupeol treated B16-F10 cell line. In solid tumor model the drug also inhibited vasculogenic mimicry along with angiogenesis by altering both the cancer stem cell as well as the endothelial progenitor cell population. Lupeol hindered the maturation of bone marrow derived endothelial progenitors and thus, retarded the formation of rudimentary tumor microvessels. Notably, Dacarbazine treatment demonstrated unresponsiveness to B16-F10 cells in both in vivo and in vitro model via upregulation of CD 133 expression and increased formation of vasculogenic mimicry tubes. Together, these data indicate that Lupeol alone can become a proficient agent in treating melanoma, inhibiting vasculogenic mimicry and might play a significant role in subduing Dacarbazine induced drug resistance.

Protective Effects of Compounds in Bombax ceiba flower on Benzo[a]pyrene-Induced Cytotoxicity

The methanolic extract of the flower of Bombax ceiba was found to show protective effects on cytotoxicity induced by benzo[a]pyrene (BaP) in HT1080 cells. We therefore tried to examine and estimate the active constituents. We isolated 16 compounds from the extract, including four butyrolactones and two ascorbic acid derivatives, as well as mangiferin. Among the isolated compounds, a butyrolactone derivative, (-)-loliolide, and two flavonoids, kaempferol 3- O-β-D-glucopyranoside and quercetin 3- O-β-D-glucopyranoside, protected the cells against the BaP-induced cytotoxicity. Quercetin, the aglycone of one of the active constituents, showed a weaker effect than its glycoside. This is the first report of the protective effects of the methanolic extract of B. ceiba and its constituents on BaP-induced cytotoxicity.

Antiangiogenic activity of PLGA-Lupeol implants for potential intravitreal applications

Uncontrolled angiogenesis is directly associated with ocular diseases such as macular degeneration and diabetic retinopathy. Implantable polymeric drug delivery systems have been proposed for intravitreal applications and in the present work, we evaluated the antiangiogenic potential of PLGA ocular implants loaded with the triterpene lupeol using in vitro and in vivo models. The drug/polymer physiochemical properties of the lupeol-loaded PLGA were validated as functionally similar using differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Interestingly, in an in vitro culture system, lupeol (100μg/mL and 250μg/mL) was capable to inhibited the proliferation as well as the migration of Human Umbilical Vein Endothelial Cells (HUVEC), without interfering in cell viability, promoting a significant reduction in the percentage of vessels (39.41% and 44.12%, respectively), compared with the control group. In vivo test, by using the chorioallantoic membrane (CAM) model, lupeol-loaded PLGA ocular implants showed antiangiogenic activity comparable to the FDA-approved anti-VEGF antibody Bevacizumab. Overall, our results suggest lupeol-loaded PLGA ocular implants were able to inhibit the angiogenic process by impairing both proliferation and migration of endothelial cells.

Triterpenes with healing activity: A systematic review

The purpose of this review was to systematically evaluate the literature on the efficacy of triterpenes for wound healing. We searched for original studies in the Medline, SCIDIRECT and LILACS databases published from 1910 to 2013. For each study, the title, abstract and full article were evaluated by two reviewers. We identified 2181 studies; however, after application of the inclusion and exclusion criteria, only 12 studies were subjected to further review. In surgical wounds, the triterpenes induced a reduction in time to closure, and this effect was reported in virtually all wound types. Triterpenes also modulate the production of ROS in the wound microenvironment, accelerating the process of tissue repair. Triterpenes may also induce cell migration, cell proliferation and collagen deposition. Although the pharmacological effects of triterpenes are well characterized, little is known about their effects in cells involved in healing, such as keratinocytes and fibroblasts. In addition, the lack of studies on the risks associated with the therapeutic use of triterpenes is worrisome. Our study reveals that triterpenes seem to favor wound healing; however, toxicological studies with these compounds are required. Taken together, these findings show that the triterpenes are a class of molecules with significant promise that leads for the development of new drugs to treat skin injury.

Rnaset2 inhibits melanocyte outgrowth possibly through interacting with shootin1

BACKGROUND

Impaired dendrite outgrowth of melanocytes is one of the reasons triggering vitiligo. RNASET2 was identified as one of the risk genes for vitiligo in a GWAS study conducted in the Chinese Han population. However, the role of Rnaset2 in the outgrowth of melanocytes is rarely studied.

OBJECTIVE

This study is to investigate the effects of Rnaset2 in regulating the outgrowth of melanocytes and its interacting proteins.

METHODS

Stress conditions (UV irradiation, hydrogen peroxide, and lipopolysaccharides) were applied to primary human epidermal melanocytes (HEMs) and epidermal keratinocytes (HEKs). HEKs with Rnaset2 overexpression were co-cultured with HEMs. Rnaset2 expression levels were detected by ELISA. HEMs, HEKs and A375 cells were treated with recombinant Rnaset2 protein and actin network was observed with fluorescence microscope. Cell migration assay was performed using nuclepore filters after incubating A375 cells with recombinant Rnaset2 protein. Human proteome microarray was performed to identify proteins interacting with Rnaset2. Co-immunoprecipitation was conducted to verify the results.

RESULTS

Our results showed that after exposing to stress conditions, Rnaset2 expression and secretion by HEKs and HEMs were increased. Co-culture of HEKs and HEMs showed that outgrowth of HEMs was inhibited by Rnaset2 overexpression in HEKs. Additionally, human recombinant Rnaset2 protein treatment altered the actin network of HEMs, HEKs and A375 cells. The migration of A375 cells was also inhibited by human recombinant Rnaset2 protein treatment. Human proteome microarray identified shootin1, an important protein involved in axon outgrowth, as one of the interacting proteins of Rnaset2. Co-immunoprecipitation confirmed that Rnaset2 interacted with shootin1 in vitro.

CONCLUSION

Rnaset2 inhibits melanocyte outgrowth through interacting with shootin1 and this effect may be associated with vitiligo pathogenesis. Rnaset2 may be a potential therapeutic target for vitiligo.

Targeting drivers of melanoma with synthetic small molecules and phytochemicals

Melanoma is the least common form of skin cancer, but it is responsible for the majority of skin cancer deaths. Traditional therapeutics and immunomodulatory agents have not shown much efficacy against metastatic melanoma. Agents that target the RAS/RAF/MEK/ERK (MAPK) signaling pathway - the BRAF inhibitors vemurafenib and dabrafenib, and the MEK1/2 inhibitor trametinib - have increased survival in patients with metastatic melanoma. Further, the combination of dabrafenib and trametinib has been shown to be superior to single agent therapy for the treatment of metastatic melanoma. However, resistance to these agents develops rapidly. Studies of additional agents and combinations targeting the MAPK, PI3K/AKT/mTOR (PI3K), c-kit, and other signaling pathways are currently underway. Furthermore, studies of phytochemicals have yielded promising results against proliferation, survival, invasion, and metastasis by targeting signaling pathways with established roles in melanomagenesis. The relatively low toxicities of phytochemicals make their adjuvant use an attractive treatment option. The need for improved efficacy of current melanoma treatments calls for further investigation of each of these strategies. In this review, we will discuss synthetic small molecule inhibitors, combined therapies and current progress in the development of phytochemical therapies.

From a traditional medicinal plant to a rational drug: understanding the clinically proven wound healing efficacy of birch bark extract

BACKGROUND

Birch bark has a long lasting history as a traditional medicinal remedy to accelerate wound healing. Recently, the efficacy of birch bark preparations has also been proven clinically. As active principle pentacyclic triterpenes are generally accepted. Here, we report a comprehensive study on the underlying molecular mechanisms of the wound healing properties of a well-defined birch bark preparation named as TE (triterpene extract) as well as the isolated single triterpenes in human primary keratinocytes and porcine ex-vivo wound healing models.

METHODOLOGY/PRINCIPAL FINDINGS

We show positive wound healing effects of TE and betulin in scratch assay experiments with primary human keratinocytes and in a porcine ex-vivo wound healing model (WHM). Mechanistical studies elucidate that TE and betulin transiently upregulate pro-inflammatory cytokines, chemokines and cyclooxygenase-2 on gene and protein level. For COX-2 and IL-6 this increase of mRNA is due to an mRNA stabilizing effect of TE and betulin, a process in which p38 MAPK and HuR are involved. TE promotes keratinocyte migration, putatively by increasing the formation of actin filopodia, lamellipodia and stress fibers. Detailed analyses show that the TE components betulin, lupeol and erythrodiol exert this effect even in nanomolar concentrations. Targeting the actin cytoskeleton is dependent on the activation of Rho GTPases.

CONCLUSION/SIGNIFICANCE

Our results provide insights to understand the molecular mechanism of the clinically proven wound healing effect of birch bark. TE and betulin address the inflammatory phase of wound healing by transient up-regulation of several pro-inflammatory mediators. Further, they enhance migration of keratinocytes, which is essential in the second phase of wound healing. Our results, together with the clinically proven efficacy, identify birch bark as the first medical plant with a high potential to improve wound healing, a field which urgently needs effective remedies.

Possible modulation of FAS and PTP-1B signaling in ameliorative potential of Bombax ceiba against high fat diet induced obesity

BACKGROUND

Bombax ceiba Linn., commonly called as Semal, is used in various gastro-intestinal disturbances. It contains Lupeol which inhibits PTP-1B, adipogenesis, TG synthesis and accumulation of lipids in adipocytes and adipokines whereas the flavonoids isolated from B. ceiba has FAS inhibitory activity. The present study was aimed to investigate ameliorative potential of Bombax ceiba to experimental obesity in Wistar rats, and its possible mechanism of action.

METHODS

Male Wistar albino rats weighing 180-220 g were employed in present study. Experimental obesity was induced by feeding high fat diet for 10 weeks. Methanolic extract of B. ceiba extract 100, 200 and 400 mg/kg and Gemfibrozil 50 mg/kg as standard drug were given orally from 7th to 10th week.

RESULTS

Induction with HFD for 10 weeks caused significant (p < 0.05) increase in % body wt, BMI, LEE indices; serum glucose, triglyceride, LDL, VLDL, cholesterol, free fatty acid, ALT, AST; tissue TBARS, nitrate/nitrite levels; different fat pads and relative liver weight; and significant decrease in food intake (g and kcal), serum HDL and tissue glutathione levels in HFD control rats. Treatment with B. ceiba extract and Gemfibrozil significantly attenuated these HFD induced changes, as compared to HFD control. The effect of B. ceiba 200 and 400 mg/kg was more pronounced in comparison to Gemfibrozil.

CONCLUSION

On the basis of results obtained, it may be concluded that the methanolic extract of stem bark of Bombax ceiba has significant ameliorative potential against HFD induced obesity in rats, possibly through modulation of FAS and PTP-1B signaling due to the presence of flavonoids and lupeol.

Narrow-band UVB radiation promotes dendrite formation by activating Rac1 in B16 melanoma cells

Melanocytes are found scattered throughout the basal layer of the epidermis. Following hormone or ultraviolet (UV) light stimulation, the melanin pigments contained in melanocytes are transferred through the dendrites to the surrounding keratinocytes to protect against UV light damage or carcinogenesis. This has been considered as a morphological indicator of melanocytes and melanoma cells. Small GTPases of the Rho family have been implicated in the regulation of actin reorganization underlying dendrite formation in melanocytes and melanoma cells. It has been proven that ultraviolet light plays a pivotal role in melanocyte dendrite formation; however, the molecular mechanism underlying this process has not been fully elucidated. The effect of small GTPases, such as Rac1 and RhoA, on the morphology of B16 melanoma cells treated with narrow-band UVB radiation was investigated. The morphological changes were observed under a phase contrast microscope and the F-actin microfilament of the cytoskeleton was observed under a laser scanning confocal microscope. The pull-down assay was performed to detect the activity of the small GTPases Rac1 and RhoA. The morphological changes were evident, with globular cell bodies and increased numbers of tree branch-like dendrites. The cytoskeletal F-actin appeared disassembled following narrow-band UVB irradiation of B16 melanoma cells. Treatment of B16 melanoma cells with narrow-band UVB radiation resulted in the activation of Rac1 in a time-dependent manner. In conclusion, the present study may provide a novel method through which narrow-band UVB radiation may be used to promote dendrite formation by activating the Rac1 signaling pathway, resulting in F-actin rearrangement in B16 melanoma cells.

Systemic and local injections of lupeol inhibit tumor growth in a melanoma-bearing mouse model

Melanoma is the most aggressive type of skin cancer and it is procured from activated or genetically altered epidermal melanocytes. In the present study, the tumor-suppressive effects of systemic and local injections of lupeol, a triterpene extracted from Indian lettuce (Lactuca indica), in a melanoma-bearing mouse model were evaluated. Mice were injected once with lupeol or olive oil (solvent control) subcutaneously into the skin of the back or into the tumor tissue. Seven days after the injection, the tumor growth rates were calculated and the tumor tissues were collected. Immunohistochemical staining for Ki-67 and proliferating cell nuclear antigen (PCNA) were performed. The tumor growth rates in the lupeol-injected group were significantly decreased compared to those observed in the non-treated (NT) and solvent control groups. Lupeol also significantly decreased the areas positively stained for Ki-67 and PCNA in the tumor tissues compared to those in the NT and solvent control groups. The results of the present study demonstrated that systemic and local injections of lupeol suppress tumor growth and induce cell cycle arrest in a melanoma-bearing mouse model. These data suggest that lupeol may be effective as a novel therapeutic option for melanoma patients.

Emerging phytochemicals for prevention of melanoma invasion

Cutaneous malignant melanoma is the leading cause of death from skin diseases due to its propensity to metastasize. Once diagnosed with metastatic melanoma, most patients will die of their disease within 2years. As suppression of metastases requires long-term interventions, potential anti-metastatic agents must not only be efficacious but also have low toxicity. Many phytochemicals used in traditional medicine have low toxicity and recent studies suggest that some are promising candidates for the prevention or treatment of metastatic melanoma. Here, we review the recent literature regarding phytochemicals that have shown inhibitory effects on melanoma cell migration or invasion.

Aegle marmelos (L.) Correa (Bael) and Its Phytochemicals in the Treatment and Prevention of Cancer

Aegle marmelos, commonly known as Bael and belonging to the family Rutaceae is an important medicinal plant in the traditional Indian system of medicine, the Ayurveda. The extract prepared by boiling the bark, leaves or roots in water is useful as laxative, febrifuge, and expectorant. The extract is also useful in ophthalmia, deafness, inflammations, catarrh, diabetes, and asthmatic complaints. The fruits are used in treating diarrhea, dysentery, stomach ache, and cardiac ailments. Scientific studies have validated many of Bael’s ethnomedicinal properties and its potential antimicrobial effects, hypoglycemic, astringent, antidiarrheal, antidysenteric, demulcent, analgesic, anti-inflammatory, antipyretic, wound-healing, insecticidal, and gastroprotective properties. In addition, studies have also shown that Bael and some of the Bael phytochemicals possess antineoplastic, radioprotective, chemoprotective, and chemopreventive effects, properties efficacious in the treatment and prevention of cancer. For the first time, the current review summarizes the results related to these properties and emphasizes aspects that require further investigation for Bael’s safe and effective use in the near future.

Review of the phytochemical, pharmacological and toxicological properties of Alstonia Scholaris Linn. R. Br (Saptaparna)

The use of ethnornedical information has immensely contributed to health care, and scientific studies have shown that the evaluation of traditionally used medicines may provide leads towards effective drug discovery. Since antiquity, Alstonia scholaris connmonly known as devil's tree has been used for the treatment of many human ailments. Literature suggests that Alstonia scholaris is useful in treating malaria, abdominal disorders, dyspepsia, leprosy, skin diseases, tumors, chronic and foul ulcers, asthma, bronchitis, helminthiasis, agalactia, and debility. Preclinical studies have shown that it possesses anti-microbial, anti-diarrhoeal, anti-plasmodial, anti-oxidant, anti-inflammatory hepatoprotective, nootrophic, anti-stress, anti-fertility, immunomodulatory, analgesic, anti-ulcer, wound healing, anti-cancer, chemopreventive, radiation protection, radiation sensitization, and chemosensitization activities. The diverse pharmacological observations are supposed to be due to the presence of alkaloids, flavonoids and phenolic acids. The bark and leaf extract when administered orally did not induce lethality or adverse affects at the limit doses of 2 000 mg/kg body weight. However when administered intraperitoneally at high concentrations, the extract showed systemic and developmental toxicities. This review addresses the experimentally authenticated facts and also suggests the need for research on chemical and pharmacological properties of Alstonia scholaris.

Botanicals for the prevention and treatment of cutaneous melanoma

Cutaneous melanoma, a cancer of melanocytes, when detected at later stages is arguably one of the most lethal cancers and the cause of more years of lost life than any other cancer among young adults. There is no standard therapy for advanced-stage melanoma and the median survival time for patients with metastatic melanoma is <1 yr. An urgent need for novel strategies against melanoma has directed research towards the development of new chemotherapeutic and biologic agents that can target the tumor by several different mechanisms. Recently, several dietary agents are being investigated for their role in the prevention and treatment of various forms of cancer and may represent the future modality of the treatment. Here, we have reviewed emerging data on botanicals that are showing promise for their potential inhibitory effect against cutaneous melanoma.

Reduction of matrix metalloproteinase-9 expression by culture filtrate of Paecilomyces farinosus J3

The aim of the present study was to investigate the anti-tumor effects of a culture filtrate of Paecilomyces farinosus J3. Various anti-tumor assays using B16 melanoma cells were carried out. Paecilomyces farinosus J3 significantly decreased the wound healing capability, invasiveness and angiogenic activity, which was confirmed by wound healing, human umbilical vein endothelial cell and invasion assays. Paecilomyces farinosus J3 strongly inhibited cell migration, tube formation and the angiogenic process in a concentration-dependent manner. Zymographic analysis also indicated a reduced expression of matrix metalloproteinase-9 (MMP-9), a 92-kDa gelatinase. Taken together, the results indicate that the anti-tumor activities of Paecilomyces farinosus J3 originate from the reduction of MMP-9 expression in B16F10 cells.

Alstonia scholaris Linn R Br in the treatment and prevention of cancer: past, present, and future

Alstonia scholaris, commonly known as devil's tree, is an important medicinal plant in the various folk and traditional systems of medicine in Asia, Australia, and Africa. The decoction, mostly prepared from the bark, is used to treat a variety of diseases of which the most important is malaria. Furthermore, ethnomedicinal practices also suggest it to be of use in treating cancer, and preclinical studies performed with cultured neoplastic cells and tumor-bearing animals having validated these observations. Additionally, the phytochemicals like echitamine, alstonine, pleiocarpamine, O-methylmacralstonine, macralstonine, and lupeol are also reported to possess antineoplastic effects. In addition to the cytotoxic effects, A scholaris is also observed to possess radiomodulatory, chemomodulatory, and chemopreventive effects and free-radical scavenging, antioxidant, anti-inflammatory, antimutagenic, and immunomodulatory activities, all of which are properties efficacious in the treatment and prevention of cancer. The current review for the first time summarizes the results related to these properties. An attempt is also made to address the lacunae in these published studies and emphasize aspects that need further investigations for it to be of use in clinics in the future.

Lupeol, a novel anti-inflammatory and anti-cancer dietary triterpene

In the Western world, an average of 250 mg per day of triterpenes (member of phytosterol family), largely derived from vegetable oils, cereals, fruits and vegetables is consumed by humans. During the last decade, there has been an unprecedented escalation of interest in triterpenes due to their cholesterol-lowering properties and evidence of this phenomenon include at least 25 clinical studies, 20 patents and at least 10 major commercially triterpene-based products currently being sold all around the world. Lupeol a triterpene (also known as Fagarsterol) found in white cabbage, green pepper, strawberry, olive, mangoes and grapes was reported to possess beneficial effects as a therapeutic and preventive agent for a range of disorders. Last 15 years have seen tremendous efforts by researchers worldwide to develop this wonderful molecule for its clinical use for the treatment of variety of disorders. These studies also provide insight into the mechanism of action of Lupeol and suggest that it is a multi-target agent with immense anti-inflammatory potential targeting key molecular pathways which involve nuclear factor kappa B (NFkappaB), cFLIP, Fas, Kras, phosphatidylinositol-3-kinase (PI3K)/Akt and Wnt/beta-catenin in a variety of cells. It is noteworthy that Lupeol at its effective therapeutic doses exhibit no toxicity to normal cells and tissues. This mini review provides detailed account of preclinical studies conducted to determine the utility of Lupeol as a therapeutic and chemopreventive agent for the treatment of inflammation and cancer.

Lupeol: connotations for chemoprevention

The perception of chemoprevention lies still in its infancy. Intervention, to slow down, arrest or reverse the process of carcinogenesis, by the use of either natural or synthetic substances individually or in combination therapy has emerged as a promising and pragmatic medical approach to reduce cancer risk. Pentacyclic lupane-type triterpenes exemplified by lupeol [lup-20(29)-en-3b-ol], are principally found in common fruit plants such as olive, mango, fig, etc. Although, lupeol exhibits an array of biological activities like anti-inflammatory, anti-arthritic, anti-mutagenic and anti-malarial activity both in in vitro and in vivo systems yet, extensive exploration in regard to establish its role as chemopreventive compound is warranted. Interest in developing lupeol based potent anti-neoplastic agents, has led to the discovery of a host of highly active derivatives exhibiting greater potencies and better therapeutic indices. This review asserts on the chemopreventive prospects of lupeol and reveals potential chemoprevention drug targets, central to which are the cell cycle regulatory pathway genes and tries to explain the mechanism operating behind its action.

Differentiation-inducing activity of lupane triterpenes on a mouse melanoma cell line

Lupane triterpenes were found to promote melanogenesis, a hallmark of B16 2F2 mouse melanoma cell differentiation. Studies of the structure-activity relationships demonstrated that the keto function at C-3 of the lupane skeleton played important roles in the melanogenic activities of lupane triterpenes on melanoma cells. The carbonyl group at C-17 of lupane triterpenes was essential against their apoptosis-inducing activity against human cancer cells via the inhibition of topoisomerase I. We investigated whether signaling mechanisms were involved in the stimulative effects of lupane triterpenes on the melanogenesis of B16 2F2 cells. In experiments using selective inhibitors against various signal transduction molecules and Western blotting analysis, it was suggested that p38 MAPK was involved in melanoma cell differentiation as a downstream effector of PKA. Lupeol (compound 1), a lupane triterpene, induced dendrite formations, a morphological hallmark of B16 2F2 cell differentiation by rearrangement of the actin cytoskeleton. The activation of cofilin, an actin depolymerizing factor, by compound 1 caused actin fiber disassembly in B16 2F2 cells. Furthermore, compound 1 was shown to inhibit the cell motilities of human melanoma and neuroblastoma in vitro.

Birch bark research and development

This review will detail progress made in the previous decade on the chemistry and bioactivity of birch bark extractive products. Current and future applications of birch bark natural products in pharmaceuticals, cosmetics, and dietary supplements for the prevention and treatment of cancer, HIV,and other human pathogens are reviewed. Current developments in the technology of birch bark processing are discussed. New approaches for the synthesis of potentially valuable birch bark triterpenoid derivatives are also reviewed.