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.

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.

Cryptolepis buchananiRoem. & Schult. is widely used in folk medicine in Southeast Asia for treating muscle tension and arthritis. This study aimed to investigate an analgesic activity of the methanol extract ofC. buchanani(CBE) in acetic acid-induced writhing response in mice, and to examine its anti-inflammatory activity in ethyl phenylpropiolate- (EPP-) induced ear edema and carrageenan-induced paw edema in rats. Its effects on cartilage degradation induced by interleukin-1β(IL-1β) in porcine cartilage explant culture were also determined. This study demonstrated that CBE significantly reduced acetic acid-induced writhing response. It also inhibited edema formation in both EPP-induced ear edema and carrageenan-induced paw edema models. In cartilage explant culture, CBE significantly reduced the sulfated glycosaminoglycan and hyaluronan released into culture media while it reserved the uronic acid and collagen within the cartilage tissues. It also suppressed the matrix metalloproteinase-2 activity with no effect on cell viability. In conclusion, CBE shows analgesic, anti-inflammatory, and chondroprotective effects in this preliminary study. Therefore, CBE may be useful as an alternative treatment for osteoarthritis.

In the original publication, the Western blot images presented in Figures 3C, 5A and 6A contained errors in image presentation

Background: Liver function tests (LFTs) measure the levels of specific enzymes and proteins in the blood that can change when the liver is damaged. Bilirubin, a byproduct of heme degradation, primarily from red blood cell breakdown (approximately 80%), is commonly included in these assessments. Although bilirubin and liver enzymes are well-established markers of liver function, they do not always indicate the presence of liver lesions. Therefore, for accurate diagnosis, changes in liver enzyme and bilirubin concentrations should be interpreted in the context of baseline characteristics such as pesticide exposure, alcohol consumption, and medication use. Objectives: To investigate the prevalence of abnormal LFTs and alterations in bilirubin concentrations among adults in Mae Ka Subdistrict, Chiang Mai, Thailand. Materials and methods: A descriptive cross-sectional study was conducted at the Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, from January to March 2024. Adults from Mae Ka Subdistrict participated in the study. A total of 102 subjects, aged 23 to 75 years (mean age 56.88±11.26 years), were included. Liver function tests, including ALT, AST, ALP, ALB, total bilirubin, and direct bilirubin, were performed using an automated analyzer (BA 400). The ALBI score and Pearson correlation were used to evaluate the relationships between liver enzymes, bilirubin levels, and baseline characteristics. A p≤ 0.05 was considered statistically significant. Data analysis was performed using SPSS version 17 and Microsoft Excel. Results: A strong correlation was observed between the use of medications for diabetes mellitus, hypertension, or hyperlipidemia and abnormal LFTs. Medication use was associated with elevations in total bilirubin (TB), ALBI score, ALT, and ALP. However, not all individuals with elevated bilirubin levels had abnormal liver enzymes, and not all individuals with abnormal liver enzymes had elevated bilirubin levels. The ALBI score identified two individuals with normal liver enzyme and albumin (ALB) levels who may require closer monitoring and further investigation for potential liver disease. Conclusion: Medication use was associated with abnormal LFTs, potentially serving as an early warning sign. The underlying non-communicable diseases (NCDs) that necessitate medication use may be the primary contributors. Early diagnosis and treatment of liver disease, along with prevention of NCDs and metabolic syndrome, may improve health outcomes in this community.