DM is a chronic, possibly deadly metabolic condition marked by inadequate or improper insulin production, resulting in high blood sugar levels. The increasing prevalence of T2DM in the general population emphasizes the need for improved and safer medical care. Consequently, the exploration of novel antidiabetic compounds is a burning need of our times. Endophytic fungi derived from medicinal plants exhibit distinctive characteristics, as they have demonstrated the potential to synthesize a range of bioactive compounds that engage various mechanisms of action targeting food metabolizing enzymes and insulin production from pancreatic β-cells (Abdel-Azeem et al., 2024). Endophytic fungi used in traditional medicine produce about 35% of the novel metabolites; some of these fungi produce compounds with carbon frameworks that have never been identified before (Toghueo et al., 2019). We therefore hypothesized that C. sativa, extensively utilized in traditional medicine by indigenous populations globally to treat a wide range of diseases, including diabetes, may harbor endophytes that produce compounds that lower blood sugar. The current report appears to be the initial study into the antidiabetic activity of endophytic fungi derived from C. sativa.
We isolated 56 endophytic fungi from various parts of C. sativa and screened them against α-amylase, α-glucosidase, DPP-IV, and pancreatic lipase for their capability to yield antidiabetic compounds. As demonstrated in this study, the antidiabetic screening of these fungal extracts using biochemical enzymatic assays revealed the antidiabetic activity of the most promising extracts with IC50 at < 100 µg/mL against α-amylase, α-glucosidase, DPP-IV, and lipase. The current investigation designates that every part of C. sativa contains one or more endophytes that can provide bioactive metabolites and therefore suggests that a rich repertoire of antidiabetic compounds may be discovered by further investigation of these endophytic fungi.
Out of the 56 fungi tested, 2 (3.7%) demonstrated significant activity (IC50 < 100 µg/mL) against α-amylase, α-glucosidase, DPP-IV, and lipase. These fungi belong to Aspergillus microsiensis (Am) and Nodulisporium verrucosum (Nv) earlier did not reported to demonstrate antidiabetic activity. Ethyl acetate extracts of both AmEE and NvEE isolated from the roots and leaves of C. sativa, respectively, were the most potent against α-amylase (IC50 87.07 ± 3.17 & 91.07 ± 4.62 µg/mL), α-glucosidase (IC50, 52.98 ± 5.48 & 60.38 ± 4.73 µg/mL), DPP-IV (IC50, 90.59 ± 3.81 & 80.19 ± 2.86 µg/mL), and lipase (IC50 73.72 ± 3.82 & 80.05 ± 4.57 µg/mL). These effects of AmEE and NvEE were comparable to their standards and were superior to those of the CREE and CLEE. Cell proliferative effects of both AmEE and NvEE on MIN6 β-cells were assessed at 24 h post-treatment with these extracts, showing a significant increase over time, culminating at 72 h of incubation. Moreover, the treatment of MIN6 β-cells to AmEE and NvEE led to the secretion of insulin observed after 48 h incubation.
A. microsiensis was first discovered in 2014, a globally red-listed fungal species of the Aspergillus genus that exhibits anti-microbial, anti-cancerous, and anti-HIV activity (Maduranga et al., 2018; Wu et al.,2019; Luyen et al., 2019). N. verrucosum has no pharmacological activity data found in the literature survey. This study presents, for the first time, the potential of N. verrucosum to yield antidiabetic compounds. GC-MS analysis of the AmEE and NvEE extracts revealed a total of approximately forty-six bioactive secondary metabolites. Among these, twelve compounds were identified as having previously reported antidiabetic activity. In AmEE, seven compounds were detected, including 2,4-Di-tert-butylphenol, 1-Nonadecene, 7,9-Di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione, Eicosyl acetate, Heptacosane, Nonacosane, and 17-Pentatriacontene. Similarly, five antidiabetic compounds were found in NvEE, such as 2-Methylcinnamic acid, 3-Isobutylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione, 1-Hexadecanol, and Tetraneurin–A, as previously reported in the literature (Table 3). The validation of mass spectra from bioactive substances was associated with the functional groups found in FTIR spectroscopy. The mass spectroscopy investigation confirmed the presence of functional groups often identified in compounds with anti-diabetic and antioxidant effects. Distinct peaks were detected in the extracts, indicating the presence of distinct functional groups and substances with potential therapeutic properties (Nischitha et al., 2022). The presence of numerous functional groups shows the complicated structure of secondary metabolites. The results indicate that more extensive chemical analyses are required to explore the potential of Am and Nv in producing antidiabetic compounds.