METHODS: Gerbils, 5-7 weeks old were infected by PbA via intraperitoneal injection of 1 × 106 (0.2 mL) infected red blood cells. Parasitemia, weight gain/loss, hemoglobin concentration, red blood cell count and body temperature changes in both control and infected groups were monitored over a duration of 13 days. RNA was extracted from the brain, spleen and whole blood to assess the immune response to PbA infection. Organs including the brain, spleen, heart, liver, kidneys and lungs were removed aseptically for histopathology.
RESULTS: Gerbils were susceptible to PbA infection, showing significant decreases in the hemoglobin concentration, RBC counts, body weights and body temperature, over the course of the infection. There were no neurological signs observed. Both pro-inflammatory (IFNγ and TNF) and anti-inflammatory (IL-10) cytokines were significantly elevated. Splenomegaly and hepatomegaly were also observed. PbA parasitized RBCs were observed in the organs, using routine light microscopy and in situ hybridization.
CONCLUSION: Gerbils may serve as a good model for severe malaria to further understand its pathogenesis.
OBJECTIVES: The anti-inflammatory and anti-catabolic actions of Diclofenac were compared with apigenin-C-glycosides rich Clinacanthus nutans (CN) leaf extract in osteoporotic-osteoarthritis rats.
METHODS: Female Sprague Dawley rats were randomized into five groups (n = 6). Four groups were bilateral ovariectomised for osteoporosis development, and osteoarthritis were induced by intra-articular injection of monosodium iodoacetate (MIA) into the right knee joints. The Sham group was sham-operated, received saline injection and deionized drinking water. The treatment groups were orally given 200 or 400 mg extract/kg body weight or 5 mg diclofenac /kg body weight daily for 28 days. Articular cartilage and bone changes were monitored by gross and histological structures, micro-CT analysis, serum protein biomarkers, and mRNA expressions for inflammation and catabolic protease genes.
RESULTS: HPLC analysis confirmed that apigenin-C-glycosides (shaftoside, vitexin, and isovitexin) were the major compounds in the extract. The extract significantly and dose-dependently reduced cartilage erosion, bone loss, cartilage catabolic changes, serum osteoporotic-osteoarthritis biomarkers (procollagen-type-II-N-terminal-propeptide PIINP; procollagen-type-I-N-terminal-propeptide PINP; osteocalcin), inflammation (IL-1β) and mRNA expressions for nuclear-factor-kappa-beta NF-κβ, interleukin-1-beta IL-1β, cyclooxygenase-2; and matrix-metalloproteinase-13 MMP13 activities, in osteoporotic-osteoarthritis rats comparable to Diclofenac.
CONCLUSION: This study demonstrates that apigenin-C-glycosides at 400 mg CN extract/kg (about 0.2 mg apigenin-equivalent/kg) is comparable to diclofenac in suppressing inflammation and catabolic proteases for osteoporotic-osteoarthritis prevention. Graphical abstract.