Bromelain is a mixture of proteolytic enzymes derived from pineapple (Ananas comosus) fruit and stem possessing several beneficial properties, particularly anti-inflammatory activity. However, the molecular mechanisms underlying the anti-inflammatory effects of bromelain are unclear. This study investigated the anti-inflammatory effects and inhibitory molecular mechanisms of crude and purified rhizome bromelains on lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells. RAW264.7 cells were pre-treated with various concentrations of crude bromelain (CB) or purified bromelain (PB), and then treated with LPS. The production levels of pro-inflammatory cytokines and mediators, including nitric oxide (NO), interleukin (IL)-6, and tumor necrosis factor (TNF)- were determined by Griess and ELISA assays. The expressions of inducible nitric oxide synthetase (iNOS), cyclooxygenase (COX)-2, nuclear factor kappa B (NF-B), and mitogen-activated protein kinases (MAPKs)-signaling pathway-related proteins were examined by western blot analysis. The pre-treatment of bromelain dose-dependently reduced LPS-induced pro-inflammatory cytokines and mediators, which correlated with downregulation of iNOS and COX-2 expressions. The inhibitory potency of PB was stronger than that of CB. PB also suppressed phosphorylated NF-B (p65), nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha, extracellular signal-regulated kinases, c-Jun amino-terminal kinases, and p38 proteins in LPS-treated cells. PB then exhibited potent anti-inflammatory effects on LPS-induced inflammatory responses in RAW264.7 cells by inhibiting the NF-B and MAPKs-signaling pathways.

Use of natural products is one strategy to lessen cancer incidence. Rice bran, especially from colored rice, contains high antioxidant activity. Cancer chemopreventive effects of hydrophilic purple rice bran extract (PRBE) and white rice bran extract (WRBE) on carcinogen-induced preneoplastic lesion formation in livers of rats were investigated. A 15-week administration of PRBE and WRBE did not induce hepatic glutathione S-transferase placental form (GST-P) positive foci formation as the biomarker of rat hepatocarcinogenesis. PRBE and WRBE at 500 mg/kg body weight significantly decreased number and size of GST-P positive foci in diethylnitrosamine (DEN)-initiated rats. The number of proliferating nuclear antigen positive hepatocytes were also reduced in preneoplastic lesions in both PRBE and WRBE fed DEN-treated rats. Notably, the inhibitory effect on GST-P positive foci formation induced by DEN during the initiation stage was found only in rats treated by PRBE for five weeks. Furthermore, PRBE attenuated the expression of proinflammatory cytokines involving genes including TNF-α, iNOS, and NF-κB. PBRE contained a higher number of anthocyanins and other phenolic compounds and vitamin E. PRBE might protect DEN-induced hepatocarcinogenesis in rats via attenuation of cellular inflammation and cell proliferation. Anthocyanins and other phenolic compounds, as well as vitamin E, might play a role in cancer chemopreventive activity in rice bran extract.

Bromelain, a mixture of proteases in pineapple rhizome, has beneficial biological properties. Following absorption, the compound remains biologically active in mammalian blood and tissues. Bromelain has multiple clinical and therapeutic applications because of its anti-arthritic activities. Anti-inflammation is one of the putative therapeutic effects of bromelain on osteoarthritis (OA) and rheumatoid arthritis (RA), but the molecular mechanisms in cartilage and synovial fibroblast has not been reported. Thus, in this study, interleukin (IL)-1β/oncostatin M-induced porcine cartilage and TNF-α–induced synovial fibroblast were used as the inflamed OA and RA models, respectively. The results demonstrated the chondroprotective effects of bromelain on cartilage degradation and the downregulation of inflammatory cytokine (tumor necrosis factor (TNF)-α, IL-1β, IL-6, IL-8) expression in TNF-α–induced synovial fibroblasts by suppressing NF-κB and MAPK signaling. The evidence from this study supported and explained the anti-inflammatory and analgesic effects of bromelain on arthritis in animal models and clinical studies.

Caesalpinia sappan L. has generally been used in Asian folk medicines for disease treatment. C. sappan heartwood is commonly utilized as a dyeing agent in food items, beverages, cosmetics, and clothing. The effects of three extraction techniques (maceration, reflux, and ultrasonic-assisted extraction) of C. sappan heartwood extract (CSE) on the brazilin content and potential of biological activities were investigated. The brazilin content was determined using high-performance liquid chromatography (HPLC). Quantifications of the antioxidant properties (DPPH and ABTS), the total phenolic contents, and the antimicrobial activity were also examined. Additionally, the effect of CSE on pro-inflammatory cytokine and mediator production was investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. The results showed that the CSE from the maceration and reflux methods produced high levels of brazilin and total phenolic contents, as well as having excellent antioxidant and antimicrobial activities. The macerated extract showed significant antioxidant activities with IC₅₀ values of 2.88 ± 0.01 and 0.32 ± 0.01 mg/mL from DPPH and ABTS assays, respectively. Furthermore, the CSE from the maceration method which was rich in brazilin had an anti-inflammatory response by decreasing the levels of nitric oxide (NO), interleukin (IL)-6, and tumor necrosis factor (TNF)-α on LPS-stimulated RAW 264.7 macrophage cells. These results confirmed CSE as a potential source of biological components. Antioxidant and anti-inflammatory assays proved maceration was the best extraction method.

Introduction: Antidesma thwaitesianum Müll. Arg is a tropical fruit, which has been commonly used for healthy food and traditional herbal medicine. This study aimed to investigate the anti-inflammatory effects of A. thwaitesianum fruit extract (AFE) rich in 5-hydroxymethylfurfural (5-HMF) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Methods: The chemical composition of AFE was analysed by gas chromatography/mass spectrometry (GC/MS). RAW264.7 cells were used as an in vitro inflammatory response model. RAW264.7 cells were pre-treated with various concentrations of AFE or 5-HMF and subsequently treated with LPS. Cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The production levels of pro-inflammatory cytokines and mediators, including nitric oxide (NO), interleukin (IL)-1β, and tumour necrosis factor (TNF)-α were determined by the Griess assay and enzyme-linked immunosorbent assay. The protein expression of inducible nitric oxide synthase (iNOS) was examined by western blot analysis. Results: AFE had a high content of 5-HMF (61.03% ± 0.49%). Pre-treatment with AFE and 5-HMF markedly reduced LPS-induced pro-inflammatory mediators and cytokines, namely NO, IL-1β, and TNF-α, in RAW264.7 cells; this reduction correlated with downregulation of iNOS expression. Conclusion: This study suggests that A. thwaitesianum fruit extract containing 5-HMF could modulate the LPS-induced inflammatory response by inhibiting NO, IL-1β, and TNF-α production and iNOS expression. A. thwaitesianum fruit extract rich in 5-HMF could be considered a potential therapeutic agent for the prevention of inflammation.

Antidesma thwaitesianum Müll. Arg. is one of a tropical fruit which is a good source of phenolic compounds. Here, we investigated the in vitro radical scavenging activity and effect of chlorogenic acid (CGA) and A. thwaitesianum fruit extract (AFE) against H2O2-induced cytotoxicity in RAW264.7 macrophage cells. Chemical components in the extract were analyzed by colorimetric method and high performance liquid chromatography. The results exhibited that the amount of total phenolic and total flavonoid contents in AFE were 25.486 ± 0.370 mg of gallic acid equivalents (GAE)/g extract and 7.264 ± 0.312 mg of catechin equivalents (CE)/g extract, respectively, while 114 μg/g crude extract CGA was detected in AFE. AFE showed scavenging activity against ABTS and DPPH radicals, with a 50% inhibition concentration of 11.435 ± 0.381 and 2.063 ± 0.022 mg/mL, respectively. Pretreatment with both CGA (10 µg/mL) and AFE (400 µg/mL) significantly restored cell viability in H2O2-induced cytotoxicity in RAW264.7 macrophage cells, and only CGA at the concentrations of 5 and 10 µg/mL could protect cells from apoptosis. In conclusion, CGA-containing AFE has potent in vitro antioxidant activity and can increase the cell survival in H2O2-induced RAW264.7 macrophage cells. These results support the nutritional and medical value of A. thwaitesianum fruit for health-promoting benefits. Keywords: Antidesma thwaitesianum Müll. Arg., Chlorogenic acid, Antioxidant activity, Anti-apoptotic activity, RAW264.7 macrophage cells