In-vitro Callogenesis and Screening of Antimicrobial Activity of Callus and Seed of Caesalpinia bonducella F.: A Threatened Medicinal Plant of Western Ghats

Aim: Caesalpinia bonducella Flem is a dioecious scrambling woody liana of Caesalpinoideae, a subfamily of Leguminosae. The plant is threatened and distributed in the deciduous forests of the Western Ghats of India. Being an important medicinal plant Caesalpinia bonducella F. attracted many scientists to exploit various activities associated with a number of phytoconstituents. The present study was undertaken to evaluate the most suitable media and suitable concentrations of plant growth regulators for in vitro Callogenesis and screening of antimicrobial activity of callus and seed of Caesalpinia bonducella.

Materials and Methods: Callus was initiated from stem explants, on 1x and 0.5x MS medium plus supplements. The effects of plant growth regulators on callus cultures were studied and observations were made. The in vitro antibacterial activity was performed by using extracts of callus and seed of Caesalpinia bonducella in petroleum ether and methanol against multidrug resistance organisms. The organic extracts of seed and callus of the plant at concentrations of 0.02 mg/ml - 0.1 mg/ml were taken and their activities were measured.

Results: The combination of 2.5 mgL-1 2,4-D with 2 mgL-1 BAP, resulted in the highest frequency and the highest mean percentage of callus formation (2.35 ± 0.294) with yellow friable callus. The results revealed that all the extracts had a variable degree of antibacterial activity.

Conclusions: It was observed that 2,4-D at 2.5 mgL-1 in combination with BAP,2.0 mgL-1 BAP resulted in early initiation, highest induction percentage, with frequency highest mean percentage of callus formation, Antimicrobial tests with methanol and diethyl ether extract of Caesalpinia bonducella seed powder against the clinical isolates showed the zone of inhibition for all the pathogens tested with concentration of methanolic extract of C. bonducella seed powder.