Asparagus racemosus and Geodorum densiflorum lectins induce apoptosis in cancer cells by altering proteins and genes expression

Molecular mechanisms of Asparagus racemosus willd. and Withania somnifera (L.) Dunal as chemotherapeutic adjuvants for breast cancer treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Despite various treatment modalities, the progression and metastasis of breast cancer (BC) are grave concerns due to the alarming disease-free survival rate (DFS) and overall survival rate (OS) of affected patients. Over the years, many antibiotics, synthetic compounds, medicinal plant isolates and polyherbal combinations have been used as adjuvants in therapy for the management of primary and secondary tumors. Paclitaxel (PTX)-based chemotherapy for breast cancer causes multiple adverse side effects in patients. Withania somnifera (L.) Dunal (WS) and Asparagus racemosus Willd. (AR) as Ayurveda-inspired plant-based adjuvants were investigated for their anticancer effects on MDA-MB-231 and 4T1 cells in mouse model systems.

AIM OF THE STUDY

This study focused on evaluating the adjuvant properties of WS and AR plant extracts with PTX and their effectiveness over PTX alone in terms of tumor inhibition.

MATERIALS AND METHODS

The effects of WS and AR on DNA double-strand breaks (DSBs), senescence induction and mitochondrial functions were evaluated in BC cells in vitro. The potential for cancer stem cell (CSC) inhibition was evaluated via mammosphere formation assays and CD44/CD24 immunostaining. In vivo tumor growth studies were conducted in athymic BALB/c mice for MDA-MB-231 cells and in BALB/c mice for 4T1 cells.

RESULTS

Induction of senescence was evident due to DSBs induced by the WS and AR extracts. Mammosphere formation and CD44/CD24 CSC markers were reduced after treatment with WS, AR or the combination of both in MCF-7 cells. WS or AR inhibited epithelial-to-mesenchymal transition (EMT). In vivo studies demonstrated that tumor growth inhibition was more pronounced in the treated group than in the PTX alone group and the untreated control group.

CONCLUSION

Our study showed that the use of WS or AR plant hydroalcoholic extracts in combination with paclitaxel (PTX) has better effects on sensitivity and efficacy than PTX alone, as demonstrated in in vitro BC cells and mouse models with BC cell grafts. Hence, scheduling adjuvant therapy with WS or AR alone or combined with PTX can be advantageous for the management of triple-negative BC (TNBC). Further studies are warranted in human clinical conditions to ascertain the efficacy of these treatments.

Lysosome-targeted ruthenium(II) complex encapsulated with pluronic® F-127 induces oncosis in A549 cells

Transition metal complexes with characteristics of unique packaging in nanoparticles and remarkable cancer cell cytotoxicity have emerged as potential alternatives to platinum-based antitumor drugs. Here we report the synthesis, characterization, and antitumor activities of three new Ruthenium complexes that introduce 5-fluorouracil-derived ligands. Notably, encapsulation of one such metal complex, Ru3, within pluronic® F-127 micelles (Ru3-M) significantly enhanced Ru3 cytotoxicity toward A549 cells by a factor of four. To determine the mechanisms underlying Ru3-M cytotoxicity, additional in vitro experiments were conducted that revealed A549 cell treatment with lysosome-targeting Ru3-M triggered oxidative stress, induced mitochondrial membrane potential depolarization, and drastically reduced intracellular ATP levels. Taken together, these results demonstrated that Ru3-M killed cells mainly via a non-apoptotic pathway known as oncosis, as evidenced by observed Ru3-M-induced cellular morphological changes including cytosolic flushing, cell swelling, and cytoplasmic vacuolation. In turn, these changes together caused cytoskeletal collapse and activation of porimin and calpain1 proteins with known oncotic functions that distinguished this oncotic process from other cell death processes. In summary, Ru3-M is a potential anticancer agent that kills A549 cells via a novel mechanism involving Ru(II) complex triggering of cell death via oncosis.

Antitumor Activity of a Lectin Purified from Punica granatum Pulps against Ehrlich Ascites Carcinoma (EAC) Cells

BACKGROUND

Lectins are carbohydrate-binding proteins with various pharmacological activities, such as antimicrobial, antidiabetic, antioxidant, and anticancer. Punica granatum fruit extract has traditional uses, however, the anti-cancer activity of purified lectin isolated from P. granatum pulp is yet to be reported.

OBJECTIVE

The goals of this study are purification, characterization of the lectin from P. granatum, and examination of the purified lectin's anticancer potential.

METHODS

Diethylaminoethyl (DEAE) ion-exchange chromatography was used to purify the lectin, and SDSPAGE was used to check the purity and homogeneity of the lectin. Spectrometric and chemical analysis were used to characterize the lectin. The anticancer activity of the lectin was examined using in vivo and in vitro functional assays.

RESULTS

A lectin, designated as PgL of 28.0 ± 1.0 kDa molecular mass, was isolated and purified from the pulps of P. granatum and the lectin contains 40% sugar. Also, it is a bivalent ion-dependent lectin and lost its 75% activity in the presence of urea (8M). The lectin agglutinated blood cells of humans and rats, and sugar molecules such as 4-nitrophenyl-α-D-manopyranoside and 2- nitrophenyl -β- D-glucopyranoside inhibited PgL's hemagglutination activity. At pH ranges of 6.0-8.0 and temperature ranges of 30°C -80°C, PgL exhibited the highest agglutination activity. In vitro MTT assay showed that PgL inhibited Ehrlich ascites carcinoma (EAC) cell growth in a dose-dependent manner. PgL exhibited 39 % and 58.52 % growth inhibition of EAC cells in the mice model at 1.5 and 3.0 mg/kg/day (i.p.), respectively. In addition, PgL significantly increased the survival time (32.0 % and 49.3 %) of EAC-bearing mice at 1.5 and 3.0 mg/kg/day doses (i.p.), respectively, in comparison to untreated EAC-bearing animals (p < 0.01). Also, PgL reduced the tumor weight of EAC-bearing mice (66.6 versus 39.13%; p < 0.01) at the dose of 3.0 mg/kg/day treatment. Furthermore, supplementation of PgL restored the haematological parameters toward normal levels deteriorated in EAC-bearing animals by the toxicity of EAC cells.

CONCLUSION

The results indicated that the purified lectin has anticancer activity and has the potential to be developed as an effective chemotherapy agent.

2,4-Dipropylphloroglucinol inhibits the growth of human lung and colorectal cancer cells through induction of apoptosis

Scientists are finding the most effective chemotherapeutic agents for the treatment of cancer. In the present study, we evaluated the anticancer mechanism of DPPG, a derivative of DAPG (2,4-diacetylphloroglucinol), for the first time. DPPG and DAPG inhibited 83 and 59% of human colorectal cancer HCT116 cell growth at 40.0 µg/ml, and 74 and 57% of human lung cancer A549 cell growth at 10.0 µg/ml concentrations respectively. Furthermore, DPPG and DAPG inhibited 97 and 73% colony formation of the HCT116 cells at 20.0 µg/ml concentration. DPPG and DAPG induced apoptosis in the HCT116 and A549 cells that was confirmed by Hoechst 33342 and FITC-annexin V staining. This result also revealed that ROS generated in both the HCT116 and A549 cells after treatment with DPPG. However, no ROS production was observed in HCT116 and A549 cells after treatment with DAPG. Both DAPG and DPPG significantly increased the CASP3 protein expression that was detected by staining the cells with the super-view 488-CASP3 substrate. Expression of WNT1 gene was eliminated in DPPG and DAPG treated HCT116. Expression of MAPK1 gene was entirely abolished in DPPG treated cells, whereas a significant decrease was observed for DAPG. An intense band of CASP8 gene product was observed agarose gel for DPPG treated HCT116 cells than DAPG. Molecular docking simulation showed the high binding affinities (≥ 6.5 kcal/mol) of DPPG and DAPG with target proteins WNT1, MAPK1, CASP8, and CASP3 in HCT116 cells. This manuscript demonstrated that DAPG and DPPG inhibited lung and colorectal cancer cells by inducing apoptosis. DAPG and DPPG inhibited A549 and HCT116 cells growth by inducing apoptosis.

Proteins and their functionalization for finding therapeutic avenues in cancer: Current status and future prospective

Despite the remarkable advancement in the health care sector, cancer remains the second most fatal disease globally. The existing conventional cancer treatments primarily include chemotherapy, which has been associated with little to severe side effects, and radiotherapy, which is usually expensive. To overcome these problems, target-specific nanocarriers have been explored for delivering chemo drugs. However, recent reports on using a few proteins having anticancer activity and further use of them as drug carriers have generated tremendous attention for furthering the research towards cancer therapy. Biomolecules, especially proteins, have emerged as suitable alternatives in cancer treatment due to multiple favourable properties including biocompatibility, biodegradability, and structural flexibility for easy surface functionalization. Several in vitro and in vivo studies have reported that various proteins derived from animal, plant, and bacterial species, demonstrated strong cytotoxic and antiproliferative properties against malignant cells in native and their different structural conformations. Moreover, surface tunable properties of these proteins help to bind a range of anticancer drugs and target ligands, thus making them efficient delivery agents in cancer therapy. Here, we discuss various proteins obtained from common exogenous sources and how they transform into effective anticancer agents. We also comprehensively discuss the tumor-killing mechanisms of different dietary proteins such as bovine α-lactalbumin, hen egg-white lysozyme, and their conjugates. We also articulate how protein nanostructures can be used as carriers for delivering cancer drugs and theranostics, and strategies to be adopted for improving their in vivo delivery and targeting. We further discuss the FDA-approved protein-based anticancer formulations along with those in different phases of clinical trials.