Antidiabetic Activity of an Ayurvedic Formulation Chaturmukha Rasa: A Mechanism Based Study.

OBJECTIVES: The objective of this study was to evaluate antidiabetic activity of Chaturmukha rasa based on streptozotocin induced diabetes model, alpha amylase inhibitory activity, alpha Glucosidase inhibitory activity and inhibition of sucrase. METHODS: Chaturmukha rasa was prepared as per Ayurvedic formulary. Antidiabetic activity was measured in experimentally streptozotocin induced rats. The dose was taken as 45 mg/kg, i.p. The antidiabetic activity of Chaturmukha rasa was compared Triphala Kwatha, a marketed formulation. Further In vitro ά-Amylase Inhibitory Assay, In vitro salivary amylase Inhibitory Assay, In vitro α-Glucosidase Inhibitory Assay and In vitro Sucrase Inhibitory Assay was performed with respect to Chaturmukha rasa. The IC50 value was calculated for all the above activity. RESULTS: Streptozotocin with Acarbose showed significant decrease in blood glucose level whereas streptozotocin with Triphala kwatha showed more decrease in blood glucose level than Streptozotocin with Acarbose. The combination of Streptozotocin + Triphala kwatha + Chaturmukha rasa showed a significant decrease in blood glucose level on 21st day. In vitro ά-Amylase Inhibitory Assay the Chaturmukha rasa showed IC50 value 495.94 µl when compared with Acarbose 427.33 µl, respectively. In the α-Glucosidase Inhibitory Assay Chaturmukha rasa showed IC50 value 70.93 µl when compared with Acarbose 102.28 µl, respectively. In vitro Sucrase Inhibitory Assay Chaturmukha rasa showed IC50 value 415.4 µl when compared with Acarbose 371.43 µl, respectively. CONCLUSION: This study supports that Chaturmukha rasa may inhibit diabetes by inhibition of salivary amylase or alpha Glucosidase or sucrase. This may be the mechanism by which Chaturmukha rasa inhibits diabetes. Further this study supports the usage of Chaturmukha rasa for the management of diabetes.

Phototriggered Release of Tumor-Imaging and Therapy Agents from Lyophilized Multifunctional Polyacrylamide Nanoparticles.

The success of polyacrylamide nanoparticles in drug delivery spurred the creation of variations in surface functional groups. We report herein a simple, reproducible, and efficient approach for the creation of modifiable nanoparticles that are characterized by their long-term stability and high loading efficiency. In our experiments, a hydrophobic photosensitizer, such as 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH), was able to be postloaded at more than 90% efficiency across all types of nanoparticles (NPs). Moreover, the NPs have tunable release kinetics, ranging from 9% to 23%, released by 96 h in 1% serum albumin, depending on the surface modification used. Additionally, it was observed that the NPs had a photorelease mechanism where >60% of the payload was released when exposed to at least 2 J of light. This held true with the photosensitizer and hydrophobic chemotherapeutics like curcumin. To test the impact these modifications have in vitro, two different bladder cancer cell lines were chosen (UMUC3 and T24). These nanoparticles increase the efficacy of the photosensitizer by 4-fold in UMUC3, with the cationic and amino-functionalized particles having the highest efficacy. This increase in efficacy, high uptake, and favorable subcellular localization makes the cationic modification of the nanoparticle extremely attractive for future studies.

Whole body and local hyperthermia enhances the photosensitizing efficacy of 3-[(1'-hexyloxy)ethyl]-3-Devinylpyropheophorbide-a (HPPH).

BACKGROUND AND OBJECTIVES: In this study, we evaluated the impact of hyperthermia in photosensitizing efficacy of 3-[(1'-hexyloxy)ethyl-3-devinylpyropheophorbide-a (HPPH or Photochlor) for the treatment of cancer by photodynamic therapy (PDT). STUDY DESIGN/MATERIALS AND METHODS: The outcome of both whole body hyperthermia (WBH) and local hyperthermia (LH) in combination with HPPH-PDT was determined in BALB/c and nude mice bearing Colon26 and U87 tumors, respectively. LH was performed by using an indigenously designed heating device, that was heated to the required temperature using a circulating water bath. The device which has flexible membrane on one side was placed on skin above the tumor. The temperature of the tumor was monitored using a thermocouple sensor placed on the surface of the tumor capable of measuring the temperature within 0.1°C. Uptake of the photosensitizer in tumors was determined by fluorescence using an IVIS or a Nuance Imaging System. The PDT was performed by exposing the tumors to 665 nm laser loght, (135 J/cm2 , 75 mW/cm2 ) at the maximal uptake time of HPPH. Tumor size was measured daily using vernier calipers. RESULTS: The improved PDT efficacy (long-term percentage tumor cure) in combination with hyperthermia is possible due to an increase in tumor-uptake of the photosensitizer (PS), confirmed by in vivo fluorescence imaging and also by increased tumor perfusion and decreased hypoxia as have been reported previously (Sen et al. [2011] Cancer Res. 71:3872-3880 In Vivo. 20:689-695). Interestingly, compared to whole body hyperthermia, the 14 C- HPPH biodistribution data under local hyperthermia showed similar tumor-uptake in BALB/c mice bearing Colon26 tumors, but significantly lower uptake in other organs and in the blood. CONCLUSION: Our study demonstrates that both, fever range whole body and local hyperthermia in combination with HPPH-PDT enhances the long-term tumor cure of BALB/c and nude mice implanted with Colon26 and U87 tumors respectively. Lasers Surg. Med. 50:506-512, 2018. © 2018 Wiley Periodicals, Inc.

Highly Effective Dual-Function Near-Infrared (NIR) Photosensitizer for Fluorescence Imaging and Photodynamic Therapy (PDT) of Cancer.

We report herein the synthesis and biological efficacy of near-infrared (NIR), bacteriochlorin analogues: 3-(1'-butyloxy)ethyl-3-deacetyl-bacteriopurpurin-18-N-butylimide methyl ester (3) and the corresponding carboxylic acid 10. In in vitro assays, compared to its methyl ester analogue 3, the corresponding carboxylic acid derivative 10 showed higher photosensitizing efficacy. However, due to drastically different pharmacokinetics in vivo, the PS 3 (HPLC purity >99%) showed higher tumor uptake and long-term tumor cure than 10 (HPLC purity >96.5%) in BALB/c mice bearing Colon 26 tumors. Isomerically pure R- and S- isomers of 3 (3a and 3b, purity by HPLC > 99%) under similar treatment parameters showed identical efficacy in vitro and in vivo. In addition, photosensitizer (PS) 3 showed limited skin phototoxicity and provides an additional advantage over the clinically approved chemically complex hematoporphyrin derivative as well as other porphyrin-based PDT agents, which makes 3 a promising dual-function agent for fluorescence-guided surgery with an option of phototherapy of cancer.

Polyacrylamide-based biocompatible Nanoplatform enhances the tumor uptake, PET/fluorescence imaging and anticancer activity of a chlorophyll analog.

In this report we demonstrate the outstanding advantages of multifunctional nanoplatforms for cancer-imaging and therapy. The non-toxic polyacrylamide (PAA) nanoparticles (size:18-25 nm) formulation drastically changed the pharmacokinetic profile of the ¹²4I- labeled chlorophyll-a derivative (formulated in 10% ethanol in PBS) with a remarkable enhancement in tumor uptake, and significantly reduced uptake in spleen and liver. Among the various nanoformulations investigated, the ¹²4I- labeled photosensitizer (dose: 0.6142 MBq), and the cyanine dye-nanoparticles (CD-NP) conjugate (dose 0.3 µmol/kg) in combination showed great potential for tumor imaging (PET/NIR fluorescence) in BALB/c mice bearing Colon26 tumors. Compared to free non-labeled photosensitizer, the corresponding PAA nanoformulation under similar treatment parameters showed a remarkable enhancement in long-term tumor cure by PDT (photodynamic therapy) and provides an opportunity to develop a single nanoplatform for tumor-imaging (PET/fluorescence) and phototherapy, a practical "See and Treat" approach.

Gold nanocage-photosensitizer conjugates for dual-modal image-guided enhanced photodynamic therapy.

We have demonstrated that gold nanocage-photosensitizer conjugates can enable dual image-guided delivery of photosensitizer and significantly improve the efficacy of photodynamic therapy in a murine model. The photosensitizer, 3-devinyl-3-(1'-hexyloxyethyl)pyropheophorbide (HPPH), was noncovalently entrapped in the poly(ethylene glycol) monolayer coated on the surface of gold nanocages. The conjugate is stable in saline solutions, while incubation in protein rich solutions leads to gradual unloading of the HPPH, which can be monitored optically by fluorescence and photoacoustic imaging. The slow nature of the release in turn results in an increase in accumulation of the drug within implanted tumors due to the passive delivery of gold nanocages. Furthermore, the conjugate is found to generate more therapeutic singlet oxygen and have a lower IC50 value than the free drug alone. Thus the conjugate shows significant suppression of tumor growth as compared to the free drug in vivo. Short-term study showed neither toxicity nor phenotypical changes in mice at therapeutic dose of the conjugates or even at 100-fold higher than therapeutic dose of gold nanocages.

Hexylether derivative of pyropheophorbide-a (HPPH) on conjugating with 3gadolinium(III) aminobenzyldiethylenetriaminepentaacetic acid shows potential for in vivo tumor imaging (MR, Fluorescence) and photodynamic therapy.

Conjugates of 3-(1'-hexyloxyethyl)-3-devinyl pyropheophorbide-a (HPPH) with multiple Gd(III)aminobenzyl diethylenetriamine pentacetic acid (ADTPA) moieties were evaluated for tumor imaging and photodynamic therapy (PDT). In vivo studies performed in both mice and rat tumor models resulted in a significant MR signal enhancement of tumors relative to surrounding tissues at 24 h postinjection. The water-soluble (pH: 7.4) HPPH-3Gd(III) ADTPA conjugate demonstrated high potential for tumor imaging by MR and fluorescence. This agent also produced long-term tumor cures via PDT. An in vivo biodistribution study with the corresponding (14)C-analogue also showed significant tumor uptake 24 h postinjection. Toxicological evaluations of HPHH-3Gd(III)ADTPA administered at and above imaging/therapeutic doses did not show any evidence of organ toxicity. Our present study illustrates a novel approach for the development of water-soluble "multifunctional agents", demonstrating efficacy for tumor imaging (MR and fluorescence) and phototherapy.

Diacyllipid micelle-based nanocarrier for magnetically guided delivery of drugs in photodynamic therapy.

We report the design, synthesis using nanochemistry, and characterization of a novel multifunctional polymeric micelle-based nanocarrier system, which demonstrates combined function of magnetophoretically guided drug delivery together with light-activated photodynamic therapy. Specifically, the nanocarrier consists of polymeric micelles of diacylphospholipid-poly(ethylene glycol) (PE-PEG) coloaded with the photosensitizer drug 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH), and magnetic Fe3O4 nanoparticles. The nanocarrier shows excellent stability and activity over several weeks. The physicochemical characterizations have been carried out by transmission electron micrography and optical spectroscopy. An efficient cellular uptake has been confirmed with confocal laser scanning microscopy. The loading efficiency of HPPH is practically unaffected upon coloading with the magnetic nanoparticles, and its phototoxicity is retained. The magnetic response of the nanocarriers was demonstrated by their magnetically directed delivery to tumor cells in vitro. The magnetophoretic control on the cellular uptake provides enhanced imaging and phototoxicity. These multifunctional nanocarriers demonstrate the exciting prospect offered by nanochemistry for targeting photodynamic therapy.

A novel approach to a bifunctional photosensitizer for tumor imaging and phototherapy.

Optical imaging has attracted a great attention for studying molecular recognitions because minute fluorescent tracers can be detected in homogeneous and heterogeneous media with existing laboratory instruments. In our preliminary study, a clinically relevant photosensitizer (HPPH, a chlorophyll-a analog) was linked with a cyanine dye (with required photophysical characteristics but limited tumor selectivity), and the resulting conjugate was found to be an efficient tumor imaging (fluorescence imaging) and photosensitizing agent. Compared to HPPH, the presence of the cyanine dye moiety in the conjugate produced a significantly higher uptake in tumor than skin. At a therapeutic/imaging dose, the conjugate did not show any significant skin phototoxicity, a major drawback associated with most of the porphyrin-based photosensitizers. These results suggest that tumor-avid porphyrin-based compounds can be used as "vehicles" to deliver the desired fluorescent agent(s) to tumor. The development of tumor imaging or improved photodynamic therapy agent(s) by itself represents an important step, but a dual function agent (fluorescence imaging and photodynamic therapy) provides the potential for tumor detection and targeted photodynamic therapy, combining two modalities into a single cost-effective "see and treat" approach.