Nyctanthes arbor-tristis Ameliorated FCA-Induced Experimental Arthritis: A Comparative Study among Different Extracts

Abstract

Nyctanthes arbor-tristis (NAT) is commonly used traditionally for the treatment of rheumatism and inflammatory diseases. Current study evaluates the antiarthritic potential of NAT using Freund's adjuvant-induced arthritic rat model. Treatments with methanolic, ethyl acetate, and n-hexane extracts were continued for consecutive 20 days. Macroscopic arthritic scoring and water displacement plethysmometry were used to evaluate arthritic development. Hematological and biochemical parameters were investigated and ankle joints were processed for histopathological evaluation. Qualitative phytochemical analysis and GC-MS analysis were conducted for identification of constituents. NAT extracts suppressed arthritic scoring, paw edema, infiltration of inflammatory cells, pannus formation, and bone erosion. The plant extracts ameliorated total leukocytes and platelet counts and nearly normalized red blood cells (RBC) counts and hemoglobin (Hb) content. The extracts were found safe in terms of hepatotoxicity and nephrotoxicity as determined by aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and urea levels. Comparative analysis showed that ethyl acetate extract produced the highest inhibition of paw edema. The major constituents found in ethyl acetate extract can be classified into three major classes, that is, terpenes, terpenoids, fatty acids, and iridoid glycosides. Current study showed that Nyctanthes arbor-tristis ameliorated experimental rheumatoid arthritis and ethyl acetate extract possessed the highest inhibitory activity.

Figure 1

N. arbor-tristis significantly inhibited arthritic development as determined by macroscopic arthritic scoring at days 12, 16, 20, 24, and 28. Mean ± SEM is used for data representation, where n = 6. ^∗P < 0.05, ^∗∗P < 0.01, and ^∗∗∗P < 0.001.

Figure 2

Plethysmometeric analysis showed that N. arbor-tristis significantly suppressed paw edema (a) and ethyl acetate extract exhibited the highest percentage suppression (b). Mean ± SEM is used for data representation, where n = 6. ^∗∗P < 0.01, ^∗∗∗P < 0.001.

Figure 3

Treatment with N. arbor-tristis extracts ameliorated infiltration of inflammatory cells (a), bone erosion (b), and pannus formation (c). Mean ± SEM is used for data representation, where n = 6. ^∗P < 0.05, ^∗∗P < 0.01, and ^∗∗∗P < 0.001. Symbol “∧” represents the comparison of ethyl acetate extract with other treated groups. # and ### indicate the comparison of negative control with arthritic control.

Figure 4

Representative microscopic figures of histopathological analysis (H&E). Figures (a–f), (g–l), and (m–r) represent negative control, arthritic control, n-hexane extract, ethyl acetate extract, methanolic extract, and reference control, respectively. Infiltration of inflammatory cells is represented by Figures (a–f), pannus formation is represented by Figures (g–l), and bone erosion is represented by Figures (m–r).

Figure 5

The data showed significant reduction in elevated counts of total leukocytes and platelets (a, b). Treatment with N. arbor-tristis extracts also nearly normalized RBC counts and Hb content (c, d). Mean ± SEM is used for data representation, where n = 6. ^∗P < 0.05, ^∗∗P < 0.01, and ^∗∗∗P < 0.001. Symbol “∧” represents the comparison of ethyl acetate extract with other treated groups. # and ### indicate the comparison of negative control with arthritic control.

Figure 6

N. arbor-tristis extracts were found safe in terms of hepatotoxicity and nephrotoxicity as nonsignificant difference was found among the levels of ALT (a), AST (b), urea (c), and creatinine (d). Mean ± SEM is used for data representation, where n = 6.

Figure 7

Plausible mechanism for the formation of iridoid ring from iridoid glycoside under GC-MS conditions.