In vivo anti-arthritic effect and repeated dose toxicity of standardized methanolic extracts of Buddleja cordata Kunth (Scrophulariaceae) wild plant leaves and cell culture.

ETHNOPHARMACOLOGICAL RELEVANCE

Buddleja cordata Humb. Bonpl. & Kunth, known by the population as Tepozán blanco, is a shrub plant used in traditional herbal medicine in Mexico for the treatment of tumors, cancer, sores, skin burns, rheumatic pains and diseases related to inflammatory processes such as arthritis; authors adjudicate this etno-medicinal effect to the presence of secondary metabolites in the plant such as verbascoside, however due to its low concentration in recent years biotechnological tools are applied as cell culture to biosynthesize these pharmacological active metabolites in greater quantities.

AIM OF THE STUDY

Evaluate the possible toxic effect after a daily administration of MeOH extracts from wild plant leaves (Bc-Wp), and cell culture (Bc-Cc) of B. cordata for 28 days, and after their anti-edematous and antioxidant activities in vivo, as well their effect on the cytokines profile during experimental arthritis induced by complete Freund's adjuvant.

MATERIALS AND METHODS

Both extracts were evaluated in CD1 male mice first in a toxicity test of repeated dose administrations (1 g/kg) for 28 days, after which pharmacological activity of both extracts was measure during experimental induced arthritis where three doses were tested, at the end of the study edema formation, body weight gain and antioxidant activity were measure in edema and ganglionic tissues. Finally, dose that exerted the best protective effect (250 mg/kg) was evaluated to quantify its effect over ganglionic tissue concentration of lymphocytes T CD4, and cytokines (IL-1β, TNF-α and IL-10), as well histological analysis in arthritic mice.

RESULTS

Both extracts (Bc-Wp and Bc-Cc) did not exert lethality, however body weight gain and food in-take were lower than in healthy mice administered with vehicles, also extract-treated animals showed a decrease in serum lipid concentration and only Bc-Wp extract treated animals decrease serum alkaline phosphatase after 28 daily administration compared to healthy un-treated mice. During experimental arthritis best inhibition effect over edema development was observed in those animals administered with both extracts at dose of 250 mg/kg (Bc-Wp and Bc-Cc) on day 28, compared to CFA un-treated mice. Also both extracts reduce oxidative damage over lipids and proteins at the same dose, in both ganglionic and edema tissue, as well antioxidant enzymatic response was reduced in both tissues compared to arthritic un-treated group. In ganglionic tissue of arthritic mice, CD4 lymphocytes concentration was reduced by Bc-Wp and Bc-Cc treatment (250 mg/kg) respectively, as well IL-1β, and TNF-α levels. Only arthritic animals treated with Bc-Cc extract at 250 mg/kg generated a significant increase of IL-10 doubling the levels compared to CFA un-treated group. Histological analysis of popliteal ganglion showed that both extracts decrease the incidence of lytic lesions, lipid inclusions and leukocyte infiltration.

CONCLUSION

Methanolic extracts of wild Buddleja cordata and its cell cultures did not generated lethality after a daily administration for 28 days at 1 g/kg, but it was observed that both showed a lipid-lowering effect. Also at dose of 250 mg/kg both extracts exerted anti-edematous, protection against the oxidation of lipid and proteins, regulation on antioxidant enzymatic response, down-regulation on lymphocytes CD4 producers of IL-1β and TNF-α, an increase in IL-10 levels, which caused a decrease in leukocyte infiltration in ganglionic tissue during experimental arthritis.