Two novel cucurbitacins, neocucurbitacins A and B, from the Brazilian folk medicine "Buchinha" (Luffa operculata) and their effect on PEBP2alphaA and OCIF gene expression in a human osteoblast-like Saos-2 cell line

Pharmacology, toxicology and homeopathy of Luffa operculata (L.) Cogniaux (Cucurbitaceae): Integrative review

Scientific evidence on the pharmacological and toxicological effects of Luffa operculata has been produced on a smaller scale, even though the species: (i) is edible; (ii) widely recognized in folk medicine for treating sinusitis and inducing abortion; (iii) and the basis of allopathic and homeopathic medicines. In this sense, the objective of this review is to characterize the pharmacological, toxicological and clinical profile of products based on L. operculata. After consulting 14 databases, as well as a free search on Google/Google Scholar and checking references, 85 studies were selected that met our eligibility criteria. After analysis and synthesis, we found that the products have a wide range of pharmacological activities in vitro, ex vivo and in vivo. The toxicological spectrum is also alarming in different segments such as: cytogenotoxicity, tissue toxicity, (sub-) acute, reproductive, neuro- and phytotoxicity. The intensity of the pharmacological and toxicological effects is variable, and seems to be conditioned by various factors (examples: plant organ, polarity of the extracting solvent, quantity, experimental model and route of administration). Clinical data show that the products have satisfactory efficacy, tolerability and safety in the treatment of upper airway diseases (especially rhinitis and sinusitis). Finally, we hope that the presentation of toxicological information in this review can guide the safe and rational use of L. operculata in folk medicine. It may also serve as scientific evidence for exploring the pharmacological potential of the species, avoiding its side effects.

Phytochemistry and Cytotoxic Activity of Aquilaria crassna Pericarp on MDA-MB-468 Cell Lines

The extracts of Aquilaria crassna pericarp were investigated on the MDA-MB-468, a breast cancer cell line, at desired concentration (1-50 μg/mL). The results showed that the dichloromethane (DCM) extract exhibited the strongest toxicity and was carried out subsequently. A total of nine compounds were isolated from the DCM extract using column chromatography and recrystallization, of which their structures were determined. Intriguingly, in addition to the previously reported compounds, neocucurbitacin A, a cucurbitacin triterpenoid aglycone with a lactone in ring A, was reported for the first time in the Aquilaria genus. Among the isolated compounds, cucurbitacin E highly inhibited MDA-MB-468 cell growth in a dose-dependent manner. Owing to binding abilities with the SH2 domain in the molecular docking study, cucurbitacin E, neocucurbitan A, neocucurbitan B, and cucurbitacin E 2-O-β-d-glucopyranoside act as STAT3 inhibitors and are suitable for further research. This study suggests thatAquilaria crassnafruits could serve as a promising source of natural compounds with potential anticancer effects, particularly against breast cancer.

Recent Advances in the Application of Cucurbitacins as Anticancer Agents

Cucurbitacins are tetracyclic triterpenoid secondary metabolites, widely distributed in the Cucurbitaceae family. These bitter-tasting compounds act primarily as defense mechanisms against external injuries, and thus against herbivores, and furthermore, they have also found use in folk medicine in the treatment of various diseases. Many studies have acknowledged significant biological activities of cucurbitacins, such as antioxidant and anti-inflammatory activities, antimicrobial properties, or antitumor potential. Overall, cucurbitacins have the ability to inhibit cell proliferation and induce apoptosis in various cancer cell lines. Both in vitro and in vivo studies were performed to evaluate the anticancer activity of varied cucurbitacins. Cucurbitacins offer a promising avenue for future cancer treatment strategies, and their diverse mechanisms of action make them attractive candidates for further investigation. The aim of the present study is to shed light on the chemical diversity of this group of compounds by providing the sources of origin of selected compounds and their chemical structure, as well as insight into their anticancer potential. In addition, within this paper molecular targets for cucurbitacins and signalling pathways important for cancer cell proliferation and/or survival that are affected by the described class of compounds have been presented.

Luffa operculata at a late period of gestation dysregulates melatonin and cytokines interfering with weight of dams and their male offspring

ETHNOPHARMACOLOGICAL RELEVANCE

The tea made with the fruits of Luffa operculata (L.) Cogn. (Cucurbitaceae; EBN) is popularly used as abortive.

AIM OF THE STUDY

The present work aimed at accessing how the exposition of female Wistar rats to 1.0 mg/kg of EBN (experimental group, EG), or distilled water (control group, CG), by gavage, at gestational days (GD) 17-21 interfered with the reproductive performance, and with dams' behavior after weaning.

MATERIALS AND METHODS

At post-natal day 2 (PND2), the number of male and female pups was evaluated, as well as their weight. After weaning (PND21), dams were euthanized, and their liver and kidneys were removed for histological and biochemical analyses, while the blood was used in the evaluation of cytokines IL-1α, IL-1β, IL-6 and TNF-α, corticosterone, adrenocorticotrophic hormone, melatonin, AST, ALT and creatinine levels.

RESULTS AND DISCUSSION

Dams that were treated with EBN showed an anxiety-like behavior, weight loss at the end of gestation and weight gain at weaning, accompanied with a significant decrease in pro-inflammatory cytokines and in the melatonin level. No significant histological or biochemical alterations have occurred in the liver or kidneys. The number of female pups was significantly higher in the EG. The male pups showed weight gain at PND60.

CONCLUSION

The presence of cucurbitacins is probably involved in the dysregulations that were found, due to their polycyclic steroid triterpene structure.

Vertical exposition to Luffa operculata extract deregulates behavior and hypothalamus neurotransmitters in juvenile rats

ETHNOPHARMACOLOGICAL RELEVANCE

Luffa operculata (L.) Cogn (Cucurbitaceae) is a traditional plant popularly used in the abortion induction, against sinusitis and is toxic.

AIM OF THE STUDY

To verify the influence of the aqueous extract obtained from the dry fruit of L. operculata (BNE) on the male rats vertically exposed to a subabortive dose of BNE, by evaluating alterations in behavior and neurochemical features in hypothalamus, striatum and frontal cortex, at a juvenile age, after receiving a stress challenge given by the use of the "New York subway stress" technique (NYS).

MATERIALS AND METHODS

Pregnant female rats (F0 generation) received 1.0 mg/kg BNE, or distilled water (100 mL/kg), by gavage, between gestation days GD17 and GD21. The pups were weaned at PND21 and were kept up to PND60 (juvenile age) in controlled environmental conditions. Four groups were obtained: control (CG), experimental (EG), stress control (SCG) and stress experimental (SEG) After being stressed, the animals were behavioral screened for in the open field (OF) and in light-dark box (LDB) apparatuses. They were euthanized, and the liver, kidneys and brain were removed for both macroscopic and microscopic analyses, and for quantification of vanillylmandelic acid (VMA), norepinephrine (NE), dopamine (DA) and its metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC) and the serotonin (5-HT) and its metabolite 5-hydroxyindolylacetic acid (5-HIAA) were accessed in the hypothalamus, frontal cortex and striatum.

RESULTS AND DISCUSSION

although most of the behavior changes were due to the stress challenge, the rats spent more time in the dark side of the LDB and were less likely to explore the light side, indicating that the treatment with BNE induced to fear. Interferences of BNE over behavior were due to impairment of VMA, NE, 5-HT and DA and increasing of DOPAC in the hypothalamus, and an increase of 5-HIAA in the frontal cortex, indicating alterations in the hypothalamic-hypophysis-adrenal axis (HHAA). No macroscopic or histopathological changes were observed in the liver, kidneys, or brain, although GFAP was diminished in the SCG, as expected for stressed rats.

CONCLUSION

the vertical exposition of juvenile rats to BNE led to the manifestation of fear and to a down regulation of the hypothalamic-hypophysis-adrenal axis.

Lipid-Lowering Activities of Cucurbitacins Isolated from Trichosanthes cucumeroides and Their Synthetic Derivatives

In the ongoing efforts to discover natural cholesterol-lowering compounds, dihydrocucurbitacin B, isolated from Trichosanthes cucumeroides roots, was found to promote LDL uptake by upregulating LDLR protein in a PCSK9-dependent process. In this study, an in-depth investigation of T. cucumeroides roots afforded 27 cucurbitacins (1-27), including seven new cucurbitacins (1-7), and their structures were elucidated by spectroscopic data analyses. In order to gain insight into their structure-activity relationship, cucurbitacin derivatives (B1-11 and DB1-11) were synthesized. Evaluation of lipid-lowering activities of these cucurbitacins by an LDL uptake assay in HepG2 cells revealed that most of the compounds improved the LDL uptake rate, among which hexanorisocucurbitacin D (6) and isocucurbitacin D (21) exhibited the highest activities (rates of 2.53 and 2.47, respectively), which were comparable to that of the positive control, nagilactone B (rate of 2.07). According to a mechanistic study by Western blot analysis, compounds 6 and 21 dose-dependently increased LDLR protein levels and reduced PCSK9 protein levels, representing promising new lipid-lowering drug candidates.

Neocucurbitacin D, a novel lactone-type norcucurbitacin as xanthine oxidase inhibitor from Herpetospermum pedunculosum

A novel lactone-type norcucurbitacin, designated as neocucurbitacin D (1), together with five known cucurbitane triterpenes were isolated from traditional Tibetan medicine "Se Ji Mei Duo", which is the seed of Herpetospermum pedunculosum (Ser.) C.B. Clarke. The structure of neocucurbitacin D was elucidated by spectroscopic analysis, including 2D NMR and X-ray techniques. Compounds 1-6 were screened for their xanthine oxidase (XOD) inhibitory activity. Compound 1, 2 and 4 exhibited significant XOD inhibition with IC₅₀ values ranging from 10.16 to 18.41 μM. The absolute stereochemistry and XOD inhibitiory activity of lactone-type norcucurbitacins was reported firstly.

Luffa operculata fruit aqueous extract induces motor impairments, anxiety-like behavior, and testis damage in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Luffa operculata (L.) Cogn., Cucurbitaceae (buchinha-do-norte), aqueous extract (EBN) is popularly used to relieve symptoms of sinusitis and as abortive.

AIM OF THE STUDY

As neurotoxicity and toxicity studies on the male reproductive system are scarce, the present study aimed at quantitatively addressing the question.

MATERIALS AND METHODS

Male adult rats were observed in the open field (OF) and in the light-dark box test (LDB) to evaluate locomotion and anxiety. Macroscopical and microscopical alterations on the rats' testes were also studied. The rats were divided into two groups, control (GC) and experimental (GE). GE received 1.0 mg/kg per day of EBN, orally, for five consecutive days, whereas GC received water. On the 6th day, each animal was evaluated in OF and in LDB for 3 min in each apparatus. After that, the left testicles were studied.

RESULTS

In the OF, GE showed decreased locomotion, increased immobility time and decreased grooming and remained for less time in the center of the apparatus. In LDB, GE showed significant difficulty in moving into the light side of the device and remained longer in the dark side, exhibiting less displacement on both sides and less transitions between sides. Testicle weights, relative weights, testicular volume, cranial-caudal and lateral-lateral axes presented an increase in relation to the GC. Microscopic changes were observed in parenchyma, lumen and diameter of seminiferous tubules. Leydig cell numbers were decreased in GE.

CONCLUSIONS

The administration of EBN induced anxiety-like behavior, impaired locomotion and altered the testes morphology of rats.

Bioassay-guided isolation and identification of cytotoxic compounds from Bolbostemma paniculatum

ETHNOPHARMACOLOGICAL RELEVANCE

Bolbostemma paniculatum (Maxim.) Franquet (B. paniculatum), also named "Tu-bei-mu" in Chinese folk medicines, has been described in application for the treatment of tumors, warts, inflammation and toxication in traditional Chinese medicinal books. The major constituents in B. paniculatum are triterpenoid saponins, which have been proved to possess dramatically cytotoxic activity and antivirus activity. The aim of this study is to isolate and identify the active triterpenoid saponin from the bulb of B. paniculatum by a bioassay-guided method.

MATERIALS AND METHODS

Four cucurbitacine triterpenoid sapogenins and 11 triterpenoid saponins were isolated from the active EtOAc and n-BuOH extract of B. paniculatum by using bioassay-guided screening. Their structures were elucidated based on the spectroscopic methods and compared with published data. Cytotoxic activities of isolated compounds were determined by MTT assay.

RESULTS

Four cucurbitacine triterpenoid sapogenins, isocucurbitacin B(1), 23,24-dihydroisocucurbitacin B(2), cucurbitacin E(3), 23,24-dihydrocucurbitacin E(4), and 11 triterpenoid saponins, tubeimosideI(5), tubeimoside III(6), tubeimoside V(7), dexylosyltubeimoside III(8), lobatoside C(9), tubeimoside A(10), tumeimoside B(11), lobatoside A(12), tubeimoside C(13), tubeimoside IV(14), 7β,18,20,26-tetrahydroxy-(20S)-dammar-24E-en-3-O-α-L-(4-acetyl)arabinopyranosyl-(1→2)-β-D-glucopyranoside(15) were isolated from the active EtOAc and n-BuOH extracts. Of them, compounds 2, 4, 9 and 12 were firstly isolated from the Bolbostemma genus. MTT assay revealed that compounds 1, 3 and 4 had significantly activities against HeLa and HT-29 human cancer cells with IC50 values ranging from 0.93 to 9.73μM. It is worth mentioning that compound 4׳s activities against the two cell lines are 12- and 8-fold that of the positive control drug (5-Fu). Whereas, the cyclic bisdesmosides 5-9 exerted significantly activities on BGC-823, HeLa, HT-29 and MCF-7 cancer cells with IC50 values ranging from 1.30 to 15.64μM. And 6׳s activities against the four cell lines are 6-, 3-, 10- and 16-fold that of 5-Fu and 8׳s activities against the four cell lines are 5-, 3-, 14- and 9-fold that of 5-Fu.

CONCLUSION

The cytotoxic activity of the bulbs of B. paniculatum is mainly ascribable to cucurbitacine triterpenoid sapogenins (1-4) and the cyclic bisdesmosides (5-9). The cyclic bisdesmosides are the main anti-cancer active compounds of B. paniculatum. The above results provide scientific evidence to support, to some extent, the ethnomedicinal use of B. paniculatum as anticancer remedies in traditional Chinese medicine.

Cucurbitacins and cucurbitane glycosides: structures and biological activities

The natural cucurbitacins constitute a group of triterpenoid substances which are well-known for their bitterness and toxicity. Structurally, they are characterized by the tetracyclic cucurbitane nucleus skeleton, namely, 19-(10-->9beta)-abeo-10alpha-lanost-5-ene (also known as 9beta-methyl-19-norlanosta-5-ene), with a variety of oxygen substitutions at different positions. According to the characteristics of their structures, cucurbitacins are divided into twelve categories. The biological effects of the cucurbitacins are also covered.

Two New Cucurbitacin Glucosides, Opercurins A and B, from the Brazilian Folk Medicine "Buchinha" (Luffa operculata)

The structures of two new cucurbitacin glucosides designated opercurins A (1) and B (2), isolated from the fruit of Luffa operculata, have been confirmed by extensive spectroscopic investigation.