HPLC-PDA Method for Quantification of Bioactive Compounds in Crude Extract and Fractions of Aucklandia costus Falc. and Cytotoxicity Studies against Cancer Cells.

Aucklandia costus Falc. (Synonym: Saussurea costus (Falc.) Lipsch.) is a perennial herb of the family Asteraceae. The dried rhizome is an essential herb in the traditional systems of medicine in India, China and Tibet. The important pharmacological activities reported for Aucklandia costus are anticancer, hepatoprotective, antiulcer, antimicrobial, antiparasitic, antioxidant, anti-inflammatory and anti-fatigue activities. The objective of this study was the isolation and quantification of four marker compounds in the crude extract and different fractions of A. costus and the evaluation of the anticancer activity of the crude extract and its different fractions. The four marker compounds isolated from A. costus include dehydrocostus lactone, costunolide, syringin and 5-hydroxymethyl-2-furaldehyde. These four compounds were used as standard compounds for quantification. The chromatographic data showed good resolution and excellent linearity (r2 ˃ 0.993). The validation parameters, such as inter- and intraday precision (RSD < 1.96%) and analyte recovery (97.52-110.20%; RSD < 2.00%),revealed the high sensitivity and reliability of the developed HPLC method. The compounds dehydrocostus lactone and costunolide were concentrated in the hexane fraction (222.08 and 65.07 µg/mg, respectively) and chloroform fraction (99.02 and 30.21 µg/mg, respectively), while the n-butanol fraction is a rich source of syringin (37.91 µg/mg) and 5-hydroxymethyl-2-furaldehyde (7.94 µg/mg). Further, the SRB assay was performed for the evaluation of anticancer activity using lung, colon, breast and prostate cancer cell lines. The hexane and chloroform fractions show excellent IC50 values of 3.37 ± 0.14 and 7.527 ± 0.18 µg/mL, respectively, against the prostate cancer cell line (PC-3).

Optimization of indole acetic acid produced by plant growth promoting fungus, aided by response surface methodology.

Indole acetic acid (IAA) is one of the prime communicator playing a chief role in the interaction between host plant and endophytes. IAA produced by the endophytes primarily contributes to plant growth and development. Here, we optimized IAA production by an endophytic fungus Diaporthe terebinthifolli GG3F6 isolated from the asymptomatic rhizome of Glycyrrhiza glabra employing response surface methodology (RSM) and exploring its effect on the host plant biology. The methodology revealed 1.1 fold increases in IAA accumulation. The maximum IAA (121.20 µg/mL) was achieved using tryptophan substrate (1 mg/mL) in Potato dextrose broth (48 g/L) adjusted to pH 12 and incubated at 35 °C for 7 days. The significantly low p-value (p < 0.0001) of the experiment propounded that the model best fits the experimental data, and the independent variables have considerable effects on the production of IAA. Morphologically, the in-vitro grown G. glabra plants showed enhanced root and shoot growth when co-cultivated with the isolated endophytic fungal strain (GG3F6) relative to the control plants. Also, the enhanced accumulation of total phenolic (10.7 %) and flavonoid (10.2 %) in the endophyte treated plants was observed. The optimization of IAA production by an endophytic fungus using (RSM) has not been reported so far. Interestingly, 2.1 fold increase in glycyrrhizin content was recorded in GG3F6 treated in-vitro host plants as compared to the control plants. This suggested a potential use of D. terebinthifolli as a biostimulator for plant and enhanced accumulation of glycyrrhizin. The study highlights the dynamic host-endophyte interaction for exploitation in agricultural and pharmaceutical applications.