Synthesis of novel piperazine-based bis(thiazole)(1,3,4-thiadiazole) hybrids as anti-cancer agents through caspase-dependent apoptosis

A series of novel piperazine-based bis(thiazoles) 13a-d were synthesized in moderate to good yields via reaction of the bis(thiosemicarbazones) 7a, b with an assortment of C-acetyl-N-aryl-hydrazonoyl chlorides 8a-f. Similar treatment of the bis(thiosemicarbazone) 7a, b with C-aryl-N-phenylhydrazonoyl chlorides 10a, b afforded the expected bis(thiadiazole) based piperazine products 13b-d in reasonable yields. Cyclization of 7a, b with two equivalents of α-haloketones 14a-d led to the production of the corresponding bis(4-arylthiazol)piperazine derivatives 15a-h in good yields. The structures of the synthesized compounds were confirmed from elemental and spectral data (FTIR, MALDI-TOF, 1H, and 13C NMR). The cytotoxicity of the new compounds was screened against hepatoblastoma (HepG2), human colorectal carcinoma (HCT 116), breast cancer (MCF-7), and Human Dermal Fibroblasts (HDF). Interestingly, all compounds showed promising cytotoxicity against most of the cell lines. Interestingly, compounds 7b, 9a, and 9i exhibited IC50 values of 3.5, 12.1, and 1.2 nM, respectively, causing inhibition of 89.7%, 83.7%, and 97.5%, compared to Erlotinib (IC50 = 1.3 nM, 97.8% inhibition). Compound 9i dramatically induced apoptotic cell death by 4.16-fold and necrosis cell death by 4.79-fold. Compound 9i upregulated the apoptosis-related genes and downregulated the Bcl-2 as an anti-apoptotic gene. Accordingly, the most promising EGFR-targeted chemotherapeutic agent to treat colon cancer was found to be compound 9i.

The Cytotoxic Activity of Dammarane-Type Triterpenoids Isolated from the Stem Bark of Aglaia cucullata (Meliaceae)

The Aglaia genus, a member of the Meliaceae family, is generally recognized to include a number of secondary metabolite compounds with diverse structures and biological activities, including triterpenoids. Among the members of this genus, Aglaia cucullata has been reported to have unique properties and thrives exclusively in mangrove ecosystems. This plant is also known to contain various metabolites, such as flavaglines, bisamides, and diterpenoids, but there are limited reports on the isolation of triterpenoid compounds from its stem bark. Therefore, this research attempted to isolate and elucidate seven triterpenoids belonging to dammarane-type (1-7) from the stem bark of Aglaia cucullata. The isolated compounds included 20S,24S-epoxy-3α,25-dihydroxy-dammarane (1), dammaradienone (2), 20S-hydroxy-dammar-24-en-3-on (3), eichlerianic acid (4), (20S,24RS)-23,24-epoxy-24-methoxy-25,26,27-tris-nor dammar-3-one (5), 3α-acetyl-cabraleahydroxy lactone (6), and 3α-acetyl-20S,24S-epoxy-3α,25-dihydroxydammarane (7). Employing spectroscopic techniques, the chemical structures of the triterpenoids were identified using FTIR, NMR, and HRESITOF-MS. The cytotoxic activity of compounds 1-7 was tested with the PrestoBlue cell viability reagent against MCF-7 breast cancer, B16-F10 melanoma, and CV-1 normal kidney fibroblast cell lines. The results displayed that compound 5 had the highest level of bioactivity compared to the others. Furthermore, the IC₅₀ values obtained were more than 100 μM, indicating the low potential of natural dammarane-type triterpenoids as anticancer agents. These findings provided opportunities for further studies aiming to increase their cytotoxic activities through semi-synthetic methods.

Ethnobotanical study of plants used by the Munda ethnic group living around the Sundarbans, the world's largest mangrove forest in southwestern Bangladesh

ETHNOPHARMACOLOGICAL RELEVANCE

Indigenous knowledge of medicinal plants is an integral part of the primary health care (PHC) system in almost every society. For more than two centuries, Munda, a small ethnic group in Bangladesh, has lived around the Sundarbans, the world's largest mangrove forest. This mangrove is rich in biodiversity but is threatened by global climate change. Information on the therapeutic use of plants by Munda ethnic minorities remains completely unknown. Therefore, it needs urgent documentation.

AIM OF THE STUDY

The purpose of the study is (1) to search and compile data on the diversity of medicinal plants used by the Munda people for PHC needs, and (2) Quantitative analysis of these data to identify important medicinal plants and diseases related to treatment by this species.

MATERIAL AND METHODS

We conducted repeated field surveys and interviews among 79 Munda informants to collect ethnobotanical data. Informants were selected through random sampling techniques and interviewed using an open and semi-structured questionnaire. We reported the primary (absolute) data as use reports (URs) with frequency citation (FC). The International Classification of Primary Care-2 (ICPC-2) was followed to categorize the therapeutic use of medicinal plants, and quantitative analysis was performed using the FC and informant consensus factor (ICF).

RESULTS

The present study explored and compiled a total of 3199 medicinal URs for 98 medicinal plant species to treat 132 ailment conditions under sixteen (16) ICPC-2 pathological groups. The highest URs (948) were noted for the digestive (D) group treated by 69 plant species, where the highest ICF value was measured for the social problem (Z) disease category (ICF: 1.00). Of the recorded medicinal plants, 17 were identified as true Mangrove (MNG), 24 as Mangrove Associates (MNA), and 57 as Non-Mangrove (NMG) species. Fabaceae (13 species) represented the leading family, followed by Lamiaceae and Compositae (5 species). Herbs (43%) have shown dominant life forms, and the leaves (41%) were frequently used plant parts. The most commonly cited preparation method was juice (24%), and the prevalent mode of administration was oral (62%). Azadirachta indica A. Juss. was the most widely used therapeutic plant species based on FC (39) values. The comparative literature review study reveals that the practices of 15 plants and their ethnomedicinal use by the Munda people are still entirely unexplored and newly reported in Bangladesh. Additionally, therapeutic use of 2 species, Brownlowia tersa (L.) Kosterm., and Dalbergia candenatensis (Dennst.) Prain has not been previously reported worldwide. In addition, 51 plant species (52%) of the total plants studied enlisted on the IUCN Red List of Threatened Species.

CONCLUSION

To our knowledge, this is the first ethnobotanical study on the Munda ethnic group in Bangladesh. This study indicates that Munda people still rely on medicinal plants for PHC and have a rich and varied traditional knowledge about the therapeutic use of plants. This study also warns of the high risk of the current availability status of plants in the study area. Therefore, this study calls for urgent steps to protect and conserve high-risk plants that can be done by taking both in-situ and ex-situ measures. In addition, further phytochemical and pharmacological investigations of the important medicinal plants cited in the study have been suggested.