Harnessing the power of native biocontrol agents against wilt disease of Pigeonpea incited by Fusarium udum.

Fusarium wilt, caused by (Fusarium udum Butler), is a significant threat to pigeonpea crops worldwide, leading to substantial yield losses. Traditional approaches like fungicides and resistant cultivars are not practical due to the persistent and evolving nature of the pathogen. Therefore, native biocontrol agents are considered to be more sustainable solution, as they adapt well to local soil and climatic conditions. In this study, five isolates of F. udum infecting pigeonpea were isolated from various cultivars and characterized morphologically and molecularly. The isolate from the ICP 8858 cultivar displayed the highest virulence of 90%. Besides, 100 endophytic bacteria, 100 rhizosphere bacteria and three Trichoderma spp. were isolated and tested against F. udum isolated from ICP 8858 under in vitro conditions. Out of the 200 bacteria tested, nine showed highest inhibition, including Rb-4 (Bacillus sp.), Rb-11 (B. subtilis), Rb-14 (B. megaterium), Rb-18 (B. subtilis), Rb-19 (B. velezensis), Eb-8 (Bacillus sp.), Eb-11 (B. subtilis), Eb-13 (P. aeruginosa), and Eb-21 (P. aeruginosa). Similarly, Trichoderma spp. were identified as T. harzianum, T. asperellum and Trichoderma sp. Notably, Rb-18 (B. subtilis) and Eb-21 (P. aeruginosa) exhibited promising characteristics such as the production of hydrogen cyanide (HCN), cellulase, siderophores, ammonia and nutrient solubilization. Furthermore, treating pigeonpea seedlings with these beneficial microorganisms led to increased levels of key enzymes (POD, PPO, and PAL) associated with resistance to Fusarium wilt, compared to untreated controls. In field trials conducted for four seasons, the application of these potential biocontrol agents as seed treatments on the susceptible ICP2376 cultivar led to the lowest disease incidence. Specifically, treatments T2 (33.33) (P. aeruginosa) and T3 (35.41) (T. harzianium) exhibited the lowest disease incidence, followed by T6 (36.5) (Carbendizim), T1 (36.66) (B. subtilis), T4 (52.91) (T. asperellum) and T5 (53.33) (Trichoderma sp.). Results of this study revealed that, P. aeruginosa (Eb-21), B. subtilis (Rb-18) and T. harzianum can be used for plant growth promotion and management of Fusarium wilt of pigeonpea.

Formulation and evaluation of semisolid dosage forms of an anti-inflammatory drug.

Curcumin is one of the commonly used dietary supplements with wide pharmacological activities but the main hindrance in the commercial exploitation of curcumin is the issue with its solubility and stability. Hence, the aim of the present study was to formulate curcumin silver nanoparticles (CSNP) by chemical reduction method and to evaluate its solubility, stability as well as diffusion properties. The CSNP was combined with potent anti-inflammatory drug Diclofenac sodium (DS) to prepare gels (F1-F7), cream (F8) and ointment (F9). The DS-CSNP was subjected to in vitro and in vivo anti-inflammatory activity by albumin denaturation method and carrageenan-induced paw oedema method using albino rats, respectively. Results of the present study revealed that CSNP possess good solution stability in different pH solutions compared to pure curcumin, and the particle size as well as zeta potential were found to be 115 nm and - 5.69 mV, respectively for CSNP. Based on the results of in vitro release study and in vitro anti-inflammatory activity, formulation F4, F5, F9 and marketed product were subjected for in vivo anti-inflammatory activity. Among the three formulations, formulation F9 showed the maximum inhibition of the oedema (82.25%) at the end of 90 min followed by F5 and F4. In addition, formulations F4, F5, and F9 exhibited better in vivo anti-inflammatory activity in comparison with the marketed product which might be due to synergistic effect of the combination of curcumin silver nanoparticles and DS. In conclusion, CSNP-incorporated DS semisolid preparations were stable and can yield promising anti-inflammatory activity compared to marketed formulation; hence, these formulation can be exploited commercially in the preparation of anti-inflammatory dosage forms.