Suppressive Effects of the Standardized Extract of Phyllanthus amarus on Type II Collagen-induced Rheumatoid Arthritis in Sprague Dawley Rats

BACKGROUND

Standardized extract of Phyllanthus amarus has been shown to possess inhibitory effects on cellular and humoral immune responses in Wistar-Kyoto rats and Balb/c mice.

OBJECTIVE

In the present study, the standardized extract of P. amarus was investigated for its suppressive effects on type II collagen-induced rheumatoid arthritis (TCIA) in Sprague Dawley rats.

METHOD

The major components of the extracts, lignans and phenolic compounds were analysed by using a validated reversed phase HPLC and LC-MS/MS. A rheumatoid arthritis rat model was induced by administering a bovine type II collagen emulsion subcutaneously at the base of tail, on day 0 and 7 of the experiment. Effects of the extract on severity assessment, changes in the hind paw volume, bone mineral density, body weight and body temperature were measured. Concentrations of cytokines (TNF-α, IL-1β, IL-1α, IL-6) released, matrix metalloproteinases (MMP-1, MMP-3 MMP-9) and their inhibitor (TIMP-1), haematological and biochemical changes were also measured. ELISA was used to measure the cytokines and proteinases in the rat serum and synovial fluid according to manufacturer's instructions.

RESULTS

The extract dose-dependently modulated the progression in physical parameters (i.e. decrease in body weight, increase in body temperature, reduced hind paw volume, reduced the severity of arthritis), bone mineral density, haematological and biochemical perturbations, serum cytokines production and levels of matrix metalloproteinases and their inhibitor in the synovial fluid. Histopathological examination of the knee joint also revealed that the extract effectively reduced synovitis, pannus formation, bone resorption and cartilage destruction.

CONCLUSION

The results suggest that the oral administration of a standardized extract of P. amarus was able to suppress the humoral and cellular immune responses to type II collagen, resulting in the reduction of the development of TCIA in the rats.

Molecular typing of haemorrhagic septicaemia-associated Pasteurella multocida isolates from Pakistan and Thailand using multilocus sequence typing and pulsed-field gel electrophoresis

A comparative genetic study of 23 field isolates and vaccine strains of Pasteurella multocida associated with haemorrhagic septicaemia cases from Pakistan and Thailand was done using pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The MLST sequence type (ST) for all 20 of the 23 isolates tested was 122. The PFGE results showed one band difference between the Pakistani and the Thai isolates. Sequence type 122 is the dominant associated profile with haemorrhagic septicaemia (HS) cases in South Asia. The study supports the concept of using PFGE for short-term epidemiology and MLST for long-term epidemiology.

Natural honey modulates physiological glycemic response compared to simulated honey and D-glucose

The present study is undertaken to find out the relative glycemic tolerance of natural honey compared with simulated honey and D-glucose using oral glucose tolerance tested up to 180 min. Twenty-six healthy human subjects with mean age of 28.6 +/- 9.3 y were randomly divided into 3 groups, that is, natural honey consumers (NHC; n= 13), simulated honey consumers (AHC; n= 6), and D-glucose consumers (DGC; n= 7). After recording fasting blood glucose, the participants consumed either natural honey or simulated honey or D-glucose (1g/kg body weight). Subsequently, additional plasma glucose levels (PGLs) were recorded at 60, 120, and 180 min. At 60 min, DGC and AHC group members exhibited similar PGL elevation (that is, 52% and 47%, respectively) compared to NHC group with only 20% increment. On the other hand, after 180 min, 20% decrease in PGL was observed in the DGC group compared to 9.75% reduction in the NHC group. These observations are primarily in line with earlier studies. Results analyzed by one-way analysis of variance (ANOVA) showed significant differences between all 3 tested groups with F-statistic (19.96) and P value (< 0.005). Coefficient of variation of the NHC, AHC, and DGC groups were 14.8%, 20.2%, and 27.5%, respectively. Posthoc tests showed that glucose response was significantly lower in the NHC group at all time points (P < 0.005) compared to the AHC and DGC groups. In conclusion, natural honey stabilizes physiological glycemic response with rebound recovery of PGL.