Exploitation of microbes for enhancing bacoside content and reduction of Meloidogyne incognita infestation in Bacopa monnieri L.

Despite the vast exploration of rhizospheric microbial wealth for crop yield enhancement, knowledge about the efficacy of microbial agents as biocontrol weapons against root-knot disease is scarce, especially in medicinal plants, viz., Bacopa monnieri. In the present investigation, rhizospheric microbes, viz., Bacillus megaterium, Glomus intraradices, Trichoderma harzianum ThU, and their combinations were evaluated for the management of Meloidogyne incognita (Kofoid and White) Chitwood and bacoside content enhancement in B. monnieri var CIM-Jagriti. A novel validated method Fourier transform near infrared was used for rapid estimation of total bacoside content. A significant reduction (2.75-fold) in root-knot indices was observed in the combined treatment of B. megaterium and T. harzianum ThU in comparison to untreated control plants. The same treatment also showed significant enhancement (1.40-fold) in total bacoside contents (plant active molecule) content using Fourier transform near-infrared (FT-NIR) method that analyses samples rapidly in an hour without solvent usage and provides ample scope for natural product studies.

Beta-caryophyllene modulates expression of stress response genes and mediates longevity in Caenorhabditis elegans.

Beta-caryophyllene (BCP) is a natural bicyclic sesquiterpene and is a FDA approved food additive, found as an active ingredient in essential oils of numerous edible plants. It possesses a wide range of biological activities including anti-oxidant, anti-inflammatory, anti-cancerous and local anesthetic actions. We used the well established Caenorhabditis elegans model system to elucidate the stress modulatory and lifespan prolonging action of BCP. The present study for the first time reports the lifespan extension and stress modulation potential of BCP in C. elegans. Upon evaluation, it was found that 50µM dose of BCP increased the lifespan of C. elegans by over 22% (P≤0.0001) and significantly reduced intracellular free radical levels, maintaining cellular redox homeostasis. Moreover, the results suggest that BCP modulates feeding behavior, pharyngeal pumping and body size effectively. Further, this compound also exhibited significant reduction in intestinal lipofuscin levels. In the present investigation, we have predicted possible biological molecular targets for BCP using molecular docking approaches and BCP was found to have interaction with SIR-2.1, SKN-1 and DAF-16. The prediction was further validated in vivo using mutants and transgenic strains unraveling underlying genetic mechanism. It was observed that BCP increased lifespan of mev-1 and daf-16 but failed to augment lifespan in eat-2, sir-2.1 and skn-1 mutants. Relative quantification of mRNA demonstrated that several genes regulating oxidative stress, xenobiotic detoxification and longevity were modulated by BCP treatment. The study unravels the involvement of multiple signaling pathways in BCP mediated lifespan extension.

Isolation, structure determination, and antiaging effects of 2,3-pentanediol from endophytic fungus of Curcuma amada and docking studies.

An endophytic fungus was isolated from the rhizomes of Curcuma amada (Zingiberaceae), which was identified as Fusarium oxysporum on the basis of its morphological and molecular characters. Chromatographic separation and spectroscopic analysis of the fungal metabolite (chloroform extract) led to the identification of one pure compound having molecular formula C5H12O2, i.e., 2,3-pentanediol (1). Activity analysis of compound 1 demonstrated improved antiaging (antioxidant, thermotolerance) properties against Caenorhabditis elegans, in comparison to a similar, commercially available molecule i.e., 1,5-pentanediol (2). The effective (lower) concentration of 1 significantly showed (28.6%) higher survival percentage of the worms under thermal stress (37 ºC) compared to its higher concentration (25.3%), while similar trends were followed in oxidative stress where (22.2%) higher survival percentage was recorded in comparison to untreated control. The compound 1, however, lacked potential antimicrobial activity, indicating the plausible ramification of the position of OH group in such bioactive molecules. In silico evaluation of these molecules against common as well as unique targets corroborated better antiaging potential of 1 in comparison to that of 2. The results for the first time indicated that the utilization of the endophytic fungi of C. amada could, thus, be a possible source for obtaining non-plant-based bioactive compounds having broader therapeutic applications pertaining to age-related progressions.

Longevity-promoting effects of 4-hydroxy-E-globularinin in Caenorhabditis elegans.

In modern times, there has been a major increase in the use of plants or herbal constituents for the prevention of age-related disorders. 4-Hydroxy-E-globularinin (4-HEG) is an iridoid and a major component of Premna integrifolia. This investigation represents a breakthrough in geriatrics by showing the longevity-promoting activity of 4-HEG in the animal model Caenorhabditis elegans. 4-HEG (20µM) enhanced the mean life span of worms by over 18.8% under normal culture conditions and also enhanced their survival under oxidative stress. The longevity-promoting activity was associated with reduced reactive oxygen species (ROS) levels and fat accumulation in the worms. Gene-specific mutant studies verified the role of ROS detoxification pathways and simultaneous nuclear translocation of DAF-16 in the 4-HEG-mediated effects. Quantitative real-time PCR estimations and observations of transcriptional reporters indicated that 4-HEG was able to upregulate stress-inducible genes, viz., hsp-16.2 and sod-3. Thus, 4-HEG may serve as a lead compound of plant origin for the development of important nutraceuticals superseding the aging process.